Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion...
Transcript of Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion...
![Page 1: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/1.jpg)
Technological Aspects: High Voltage
Dan Faircloth
Ion Source Section Leader
Rutherford Appleton Laboratory
![Page 2: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/2.jpg)
Talk Outline
• High voltage and ion sources • Electric field calculation • Electrical breakdown • Insulators • Partial breakdown • Statistical variability • Factors affecting breakdown voltage • Cables and terminations • Ancillary equipment • Earthing and safety
![Page 3: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/3.jpg)
Uses of High Voltages in Ion Sources
• Extracting beams (up to 50 kV)
• Accelerating beams (up to 28000 kV)
• Initiating discharges / pre-ionising gases (up to 20 kV)
• Focusing and deflecting beams (up to 50 kV)
• Suppressing unwanted particles (up to 5 kV)
![Page 4: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/4.jpg)
Ion sources are particularly challenging for HV design
Explosive gasses (e.g. Hydrogen)
High temperatures
Other contaminants (e.g. Cs)
Magnetic fields
Large amounts of charge carriers
Stray beams: electrons and ions
Compact design
![Page 5: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/5.jpg)
Main Aim of High Voltage Design for Ion Sources
Produce reliable breakdown
... where we want it
prevent breakdown
...where we don’t want it
The two regions are only mm apart!
![Page 6: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/6.jpg)
High Voltage Breakdown
• Electric field strength is the primary factor
• In general high voltage breakdown is most likely to occur where the electric field is highest, but this depends on: Materials and gasses
Pressures
Temperatures
Surfaces
Magnetic fields
Stray beams
Charges
Photons
![Page 7: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/7.jpg)
Electric Field
• Potential gradient, electric field strength, electric field intensity, stress, E
• Units of Vm-1, kVm-1, kVmm-1, kVcm-1
• Equations, Analytical , Empirical, Numerical
dVE =
![Page 8: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/8.jpg)
Maxwell’s Equations
t∂∂
+=×∇DJH
t∂∂
−=×∇BE
0=⋅∇ B
ρ=⋅∇ D
For electrostatic fields:
0=×∇ E
ρ=⋅∇ D
φgrad−=E
ED ε=
ερφ =∇2
Laplace’s Equation 02
2
2
2
2
2
=∂∂
+∂∂
+∂∂
zyxφφφ
or
ερφφφ
=∂∂
+∂∂
+∂∂
2
2
2
2
2
2
zyxPoisson’s Equation
if ρ = 0:
![Page 9: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/9.jpg)
Using Laplace's Equation
Infinite parallel plates:
d
V 0
02
2
2
2
2
2
=∂∂
+∂∂
+∂∂
zyxφφφ
02
2
=∂∂
∴xφ
0=∂∂
+∂∂
zyφφ
φ does not vary with y or z:
1cx=
∂∂
⇒φ
21)( cxcx +=⇒φ
E
At x = 0, and at x = d, 0=φ V=φ
xdVx =∴ )(φ
dVc =∴ 1 02 =cand
φgrad−=E
dV
−=∴E
dV
=⇒ E
![Page 10: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/10.jpg)
Similarly.... 0112
2
2
2
2 =∂∂
+∂∂
+
∂∂
∂∂
⋅zrr
rrr
φϕφφ
r1
r2
φ1
φ2
( )1
2
1
211 lnln
ln)( rr
rr
r −
−
+=φφφφ
−
=
1
2
21
ln)(
rrr
rE φφ
−
=
1
21
21max
lnrrr
E φφ
Fine for simple geometries...
![Page 11: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/11.jpg)
Finding Electric Field Distributions
Teledeltos paper
Silver Paint
Manually find equipotentials
Power supply, voltmeter and probe
![Page 12: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/12.jpg)
Automated
Electrolytic tank
Finding Electric Field Distributions
![Page 13: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/13.jpg)
Thankfully we have Computers
![Page 14: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/14.jpg)
ερφφφ
=∂∂
+∂∂
+∂∂
2
2
2
2
2
2
zyx
Numerically Solving Poisson’s Equation
Direct methods • Gaussian elimination • LU decomposition method
Iterative methods • Mesh relaxation methods
- Jacobi - Gauss-Seidel - Successive over-relaxation method (SOR) - Alternating directions implicit (ADI) method
• Matrix methods - Thomas tridiagonal form - Sparse matrix methods: Stone’s Strongly Implicit Procedure (SIP) Incomplete Lower-Upper (ILU) decomposition - Conjugate Gradient (CG) methods: Incomplete Choleski Conjugate Gradient (ICCG) Bi-CGSTAB - Multi–Grid (MG) method Take your pick!
Apply discrete form to finite elements
![Page 15: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/15.jpg)
... but you won’t be the first
There are many solvers available to download Standard Masters degree project Written in every language, run on every platform
Mostly 2D Poor geometry input Poor meshing Poor post processing No/poor support If you want a free 2D solver:
![Page 16: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/16.jpg)
Commercial 3D Modelling Software
Plus others...
![Page 17: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/17.jpg)
Electrical Discharges
Arc Discharge
Glow Discharge
Log I
Breakdown Voltage
µA
nA
A
100 A A
ppro
xim
ate
Curr
ent R
ange
Thermal Arc Discharge
70 V
Dark Discharge Townsend Breakdown
Voltage Between Anode and Cathode
Background Ionisation
![Page 18: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/18.jpg)
Arc Discharge
Glow Discharge
Breakdown Voltage
µA
nA
A
100 A A
ppro
xim
ate
Curr
ent R
ange
Thermal Arc Discharge
70 V
Dark Discharge Townsend Breakdown
Voltage Between Anode and Cathode
Background Ionisation
Quark Gluon Plasma
Fusion
Z-Pinch 1M A
1G A
![Page 19: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/19.jpg)
Breakdown Voltage
µA
nA
App
roxi
mat
e Cu
rren
t Ran
ge
70 V
Dark Discharge Townsend Breakdown
Voltage Between Anode and Cathode
Background Ionisation
![Page 20: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/20.jpg)
Electrical Breakdown
• Global Breakdown – Complete rupture or failure of the insulation
between two electrodes
• Local Breakdown – Partial breakdown of part of the insulation
between two electrodes
![Page 21: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/21.jpg)
• Global break down can only occur when a highly conductive channel is formed between the two electrodes
• The journey towards high voltage breakdown depends on the degree of non uniformarity of the electric field
• Geometry of electrodes and materials and environment all play a critical role
![Page 22: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/22.jpg)
Avalanche
dxndn xx α=
John Townsend "Townsend discharge"
1897
E
xx enn α
0=
- +
By integration and nx = n0 at x = 0 x = 0
![Page 23: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/23.jpg)
Avalanche - + Electron
Swam
![Page 24: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/24.jpg)
Avalanche - +
x
ρ
Electron Swam
![Page 25: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/25.jpg)
Avalanche - +
x
E
E0
![Page 26: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/26.jpg)
Avalanche - +
x
E
Electron Swam
E0
![Page 27: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/27.jpg)
- +
Streamer
![Page 28: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/28.jpg)
- +
Streamer
Cathode directed streamer
Anode directed streamer
![Page 29: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/29.jpg)
- +
Streamer
CRACK
![Page 30: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/30.jpg)
Townsend Secondary Ionisation Coefficient, γ
dxndn xx α=
John Townsend "Townsend discharge"
1897
xx enn α
0=
Self sustaining discharge resulting in breakdown when:
1=deαγ
mpion γγγγ ++=
)1(10
−−= d
d
eeII α
α
λ
Townsend Criterion for Breakdown
γ is the number of secondary electrons produced per electron in the primary avalanche
![Page 31: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/31.jpg)
Paschen Curve
Friedrich Paschen 1889
Shorter mean
free path
![Page 32: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/32.jpg)
Paschen Curve
Friedrich Paschen 1889
Operating just below the Paschen Minimum:
Longer gaps have
lower breakdown voltages!
![Page 33: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/33.jpg)
Vacuum Breakdown Processes
![Page 34: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/34.jpg)
Vacuum Breakdown
Extraction conditioning Kilpatrick
Insulating micro- inclusions can also cause field enhancement
![Page 35: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/35.jpg)
Insulators
Something has to hold up the electrodes
![Page 36: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/36.jpg)
Surface Breakdown
Electrons Photons Neutral Gas Molecules Neutral Surface Molecules Positive Ions (Gas Molecules) Negative Ions (Gas Molecules) Positive Ions (Surface Molecules) Negative Ions (Surface Molecules)
Ambient Electric
Field
Localised Electric
Field
Insulator surfaces are the weakest part of the insulation system
![Page 37: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/37.jpg)
Impulse voltages applied to a rod-plane gap with PTFE insulator between
![Page 38: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/38.jpg)
Surface Charging
Dust Figure
Charge Distribution
+36 kV Impulse Charge Distribution
-70 kV Impulse
Polarity is very important if the gap is
asymmetrical
![Page 39: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/39.jpg)
Triple junctions always exist at some scale
Plane Electrodes
Insulator
Detail
Triple Junction Region
![Page 40: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/40.jpg)
Triple Junction Effect 1.00
0.93
0.86
0.79
0.72
0.65
0.58
0.51
0.44
0.37
0.30
Field Strength (kVm-1)
Equi
pote
ntia
ls
4mm Triple Junction
INSULATOR AIR
Fiel
d St
reng
th
INSULATOR AIR
2mm Triple Junction
INSULATOR AIR
INSULATOR AIR
1mm Triple Junction
INSULATOR AIR
INSULATOR AIR
0.5mm Triple Junction
INSULATOR AIR
INSULATOR AIR
PTFE (εr = 2.2) ambient field of 0.5 kVmm-1
![Page 41: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/41.jpg)
Triple Junction Effect
1mm triple junction ambient field of 0.5 kVmm-1
1.50
1.37
1.24
1.11
0.98
0.85
0.72
0.59
0.46
0.33
0.2
Field Strength (kVmm-1)
Equi
pote
ntia
ls
Fiel
d St
reng
th
εr = 1.0
INSULATOR AIR
INSULATOR AIR
εr = 2.2
INSULATOR AIR
INSULATOR AIR
εr = 3.6
INSULATOR AIR
INSULATOR AIR
εr = 7.0
INSULATOR AIR
INSULATOR AIR
![Page 42: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/42.jpg)
Common Insulators Material Relative
Permittivity, εr
Dielectric Strength (kV/mm)
Air 1 3
PTFE 2.2 19.7
Al2O3 8-10 13.4
Mica 6 118
Epoxy Resin 3.6 20
SF6 1.002 7.5
Oil 2.5 - 4 10 - 15
![Page 43: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/43.jpg)
Triple Junction Screening
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
Field Strength (kVmm-1)
No Screening Inside
Insulator Outside
Ring
1 mm PTFE triple junction ambient field of 0.5 kVm-1
![Page 44: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/44.jpg)
Triple Junction Screening
No Screening Recessed Insulator
Inside and Recessed
1 mm PTFE triple junction ambient field of 0.5 kVm-1
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
Field Strength (kVmm-1)
![Page 45: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/45.jpg)
![Page 46: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/46.jpg)
![Page 47: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/47.jpg)
Antenna power feed sparking
![Page 48: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/48.jpg)
A simple 2D model of the antenna power feed
![Page 49: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/49.jpg)
Demonstrated fields in excess of 3 kV mm-1
5.4 kV mm-1
![Page 50: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/50.jpg)
Partial Discharges
Cb Cv
Cx
Cy
Void
![Page 51: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/51.jpg)
Insulator Materials Depends on application! For example: Al2O3 is commonly used in sources in vacuum AlN is used when a high thermal conductivity is required Macor is used when a complex shape needs to be machined Porcelain is used in compression Epoxy resin is used to impregnate and pot Mica is used for thin high voltage withstand Glass is used when visible transparency is required
![Page 52: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/52.jpg)
Corona •Corona is another type of partial discharge occurring in very divergent fields
•Divergent fields are caused by sharp points
Equipontentials
![Page 53: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/53.jpg)
Corona •Corona is another type of partial discharge occurring in very divergent fields
•Divergent fields are caused by sharp points
Electric Field
![Page 54: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/54.jpg)
Corona •Corona is another type of partial discharge occurring in very divergent fields
•Divergent fields are caused by sharp points
•Discharge behaviour is dependant on polarity
+ Negative point
-
- Positive point
+
![Page 55: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/55.jpg)
Electrode Design •Minimise Electric Field by making smooth rounded electrodes •Shield any sharp points with corona shields
![Page 56: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/56.jpg)
![Page 57: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/57.jpg)
Breakdown strength of Air
In air at normal room conditions two electrodes require about 30 kV for each cm of spacing to breakdown (as a rule of thumb)
Or 3 kVmm-1
![Page 58: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/58.jpg)
Statistical Variability
Even with identical conditions the same electrode gap will breakdown at different voltages each time the voltage is applied. This is because of the statistical nature of high voltage breakdown: no two sparks are ever the same.
![Page 59: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/59.jpg)
![Page 60: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/60.jpg)
Environmental conditions
Higher temperatures and lower pressures lead to lower flashover voltages. A correction factor for V50% can be found from this equation:
where P is in mmHg and t is in degrees centigrade.
tP
+×
273386.0
-6 2
10
18
26
34
42
50
5860
0 660 72
0 780
0%
20%
40%
60%
80%
100%
120%
Percentage change in V50%
Temperature (Deg C)
Presure (mmHg)
Humidity can also affect breakdown voltage
![Page 61: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/61.jpg)
Polarity is important in Non Uniform Gaps
![Page 62: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/62.jpg)
Geometry Scaling factors
![Page 63: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/63.jpg)
Type of Applied
Voltage is Important
![Page 64: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/64.jpg)
Additional Complications
• Magnetic Fields
• Xrays
• Space charge
• Insulator surface charge
• Stray beam
• Contamination
![Page 65: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/65.jpg)
High Voltage Design High voltage platform or
internal isolation?
Pros and cons
![Page 66: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/66.jpg)
Cables and Terminations
Correct termination of high voltage cables is essential
![Page 67: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/67.jpg)
![Page 68: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/68.jpg)
![Page 69: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/69.jpg)
Connectors or Bushings?
Depends on...
• Application
• Maintenance
• Permanence
![Page 70: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/70.jpg)
![Page 71: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/71.jpg)
![Page 72: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/72.jpg)
![Page 73: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/73.jpg)
![Page 74: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/74.jpg)
![Page 75: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/75.jpg)
Big Bushings
800 kV Outdoor
![Page 76: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/76.jpg)
Commercial Insulators
• Dirt and Dust • Sheds • Tracking A well designed
insulation system is one you don’t ever have to worry about
![Page 77: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/77.jpg)
High voltage platforms don’t have to be too complicated, but...
![Page 78: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/78.jpg)
![Page 79: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/79.jpg)
![Page 80: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/80.jpg)
Clean lab conditions!
![Page 81: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/81.jpg)
![Page 82: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/82.jpg)
Water and home-made insulators don’t mix
![Page 83: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/83.jpg)
![Page 84: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/84.jpg)
![Page 85: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/85.jpg)
Commercial insulators are relatively cheap (≈€200) and will work in all conditions
![Page 86: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/86.jpg)
Power to the Platform
How to get power to the equipment on the HV platform?
• Motor alternator set
• Isolating transformer
• Waveguide DC break
![Page 87: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/87.jpg)
![Page 88: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/88.jpg)
Solid Insulation Isolation
Transformer
1:1
![Page 89: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/89.jpg)
Oil Filled Isolation
Transformer
Pro: Compact design Con: Bund required
Oil dielectric strength 10 – 15 kVmm-1
![Page 90: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/90.jpg)
RF Waveguide DC Breaks
Air Vacuum
Water Cooled
![Page 91: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/91.jpg)
Voltage Dividers SF6 Filled
1
2
Compensated
If R1C1 = R2C2
For all frequencies
SF6 dielectric strength 2.5 times air = 7.5 kVmm-1
![Page 92: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/92.jpg)
Insulation Test Equipment
Current limited test of insulation withstand strength
![Page 93: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/93.jpg)
Power Supply Technologies
• Semiconductors: Thyristor, IGBT, GTO • Tube- tetrode • PFN • Cascade rectifier (Greinacher/ Cockcroft–Walton
multiplier ) • Vandergraph, peloton • Linear (Usually front end only) • Switched mode-transformer -HV Diode and
Capacitor
![Page 94: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/94.jpg)
High Voltage Power Supply Manufacturers
![Page 95: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/95.jpg)
Custom Built Power Supplies
• Tight specification is essential
• Or of course you could make your own if it is specialised e.g. pulsed extraction.
![Page 96: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/96.jpg)
Tetrode used for ISIS 17 kV pulsed extraction power supply
![Page 97: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/97.jpg)
![Page 98: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/98.jpg)
Earthing Solid single point earth
![Page 99: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/99.jpg)
High voltage platform “Local earth”
![Page 100: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/100.jpg)
Safety
• Electric Shocks can kill
• Stored energy in capacitors
½CV2 = 0.5 x 1 µF x 30 kV = 450 J
• X-rays
![Page 101: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/101.jpg)
Electric Shocks
Hand to hand resistance: 100 kΩ dry/thick skin 1 kΩ wet/broken skin • The stratum corneum
breaks down 450–600 V leaving 500 Ω
• You can feel 5 mA • 60 mA can fibrillate the
heart
![Page 102: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/102.jpg)
HV Safety Philosophy
1. Impossible to accidently lock someone in the HV area.
2. Ability to shut down the power inside and outside the HV area.
3. Impossible to power on the HV without locking the area.
4. Impossible to enter the HV area without making it safe.
![Page 103: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/103.jpg)
![Page 104: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/104.jpg)
![Page 105: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/105.jpg)
![Page 106: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/106.jpg)
![Page 107: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/107.jpg)
![Page 108: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/108.jpg)
![Page 109: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/109.jpg)
HV Safety Philosophy
1. Impossible to accidently lock someone in the HV area.
2. Ability to shut down the power inside and outside the HV area.
3. Impossible to power on the HV without locking the area.
4. Impossible to enter the HV area without making it safe.
![Page 110: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/110.jpg)
![Page 111: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/111.jpg)
HV Safety Philosophy
1. Impossible to accidently lock someone in the HV area.
2. Ability to shut down the power inside and outside the HV area.
3. Impossible to power on the HV without locking the area.
4. Impossible to enter the HV area without making it safe.
![Page 112: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/112.jpg)
![Page 113: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/113.jpg)
![Page 114: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/114.jpg)
![Page 115: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/115.jpg)
![Page 116: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/116.jpg)
![Page 117: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/117.jpg)
![Page 118: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/118.jpg)
![Page 119: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/119.jpg)
![Page 120: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/120.jpg)
![Page 121: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/121.jpg)
HV Safety Philosophy
1. Impossible to accidently lock someone in the HV area.
2. Ability to shut down the power inside and outside the HV area.
3. Impossible to power on the HV without locking the area.
4. Impossible to enter the HV area without making it safe.
![Page 122: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/122.jpg)
![Page 123: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/123.jpg)
![Page 124: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/124.jpg)
Automatic Earthing System
![Page 125: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/125.jpg)
Automatic Earthing System
![Page 126: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/126.jpg)
Earth Stick
![Page 127: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/127.jpg)
![Page 128: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/128.jpg)
Earth stick should be hung just inside the entrance of the high voltage area
![Page 129: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/129.jpg)
You can never prevent humans from circumventing safety systems...
But you must make sure that they require some effort to wilfully bypass
Complacency and familiarity can kill
![Page 130: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/130.jpg)
Cautionary tale of Dr. Jon Osterman...
Example of very bad safety systems:
![Page 131: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/131.jpg)
![Page 132: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/132.jpg)
Let that be a lesson!
![Page 133: Technological Aspects: High Voltage - CERN · Technological Aspects: High Voltage Dan Faircloth Ion Source Section Leader . Rutherford Appleton Laboratory . Talk Outline • High](https://reader030.fdocuments.in/reader030/viewer/2022041222/5e0be2b5500a203f087b8a85/html5/thumbnails/133.jpg)
Thank you for listening