Beam Current MeasurementsThe State of Art

D. BelohradCERN, Geneva, Switzerland

May 18, 2011

PART I

What is the beam current/charge

What is its origin

The Intensity Measurement

3

· Movement of electrically charged particles generates a current· Beam = charged particles which move around the accelerator

I Beam intensity / Beam charge:I either an equivalent DC currentI or number of charged particles in a ’region of interest’

I Region of interest (ROI):specific time interval corresponding to a measured

structure→ next slide

I The number of charges:

NP =Q

e=

∫ROI ibeam(t)dt

e≈ I · t

e(1)

Q is a measured charge, e = 1.602× 10−19 C.

ibeam is the beam current intercepted by measurement device

Region of interest

4

Repetition rate

t [µs]

Batch length

Fine structure t [µs]

• Repetition rate = CW to seconds

• Batch length = ns to ms or CW

• Bunch spacing = ps to ms

• Bunch length σ = fs to nsσ

IDC,eq

IDC

Bunch spacing

Q =∫

ROI ib(t)dt

Bunch pattern example

Repetition rate

t [µs]

Batch length

Fine structure t [µs]

• Repetition rate = CW to seconds

• Batch length = ns to ms or CW

• Bunch spacing = ps to ms

• Bunch length σ = fs to nsσ

IDC,eq

IDC

Bunch spacing

Q =∫

ROI ib(t)dt

Bunch pattern example

I LINACs: equivalent DC current in a batch

I electron machines/fine structure: bunch charge

I circulating beam: bunch charge / DC beam current

I other, e.g. total charge over a revolution period

Additional information, e.g. amount of debunched beam

Region of interest

5

Repetition rate

t [µs]

Batch length

Fine structure t [µs]

• Repetition rate = CW to seconds

• Batch length = ns to ms or CW

• Bunch spacing = ps to ms

• Bunch length σ = fs to nsσ

IDC,eq

IDC

Bunch spacing

Q =∫

ROI ib(t)dt

Bunch pattern example

Repetition rate

t [µs]

Batch length

Fine structure t [µs]

• Repetition rate = CW to seconds

• Batch length = ns to ms or CW

• Bunch spacing = ps to ms

• Bunch length σ = fs to nsσ

IDC,eq

IDC

Bunch spacing

Q =∫

ROI ib(t)dt

Bunch pattern example

I LINACs: equivalent DC current in a batch

I electron machines/fine structure: bunch charge

I circulating beam: bunch charge / DC beam current

I other, e.g. total charge over a revolution period

Additional information, e.g. amount of debunched beam

PART II

What measurement methods are available?

What can measure the charge

7

What can give precise information about the charge?I a measurement instrument:

I provide deterministic absolute measurement valueI must be calibrated

I direct calibration - not many devices availableI indirect calibration - uses directly calibrated devices

I uncertainty of the measurement and calibration standards

I dynamic range and noise levels are of utmost importance

I Can provide: instant current, average current, bunch charge,turn charge etc.

I used for machine protection (e.g. Reeg, H. et al., EPAC2006)

Charge measurement devices

8

I non-intercepting - inductive/capacitive coupling to the beam

→ insignificant impact on the beam→ couple to EM image current ’treatment’I inductive: FBCTs, DCCTs, WCMs, striplines (EM coupling)I capacitive: BPMs, all sorts of button-style pick-upsI magnetic sensors: SQUIDs, Magneto-resistive sensors, CCCs,

nDCCT

I intercepting - direct interaction with the beam

→ absorption of significant part of the energyI Faraday cups (beam stoppers), SEM grids, screens, Ionisation

chambersI even Wire scanners can provide intensity

Charge measurement devices

9

I non-intercepting - inductive/capacitive coupling to the beam

→ insignificant impact on the beam→ couple to EM image current ’treatment’I inductive: FBCTs, DCCTs, WCMs, striplines (EM coupling)I capacitive: BPMs, all sorts of button-style pick-upsI magnetic sensors: SQUIDs, Magneto-resistive sensors, CCCs,

nDCCT

I intercepting - direct interaction with the beam

→ absorption of significant part of the energyI Faraday cups (beam stoppers), SEM grids, screens, Ionisation

chambersI even Wire scanners can provide intensity

Charge measurement devices

10

I non-intercepting - inductive/capacitive coupling to the beam

→ insignificant impact on the beam→ couple to EM image current ’treatment’I inductive: FBCTs, DCCTs, WCMs, striplines (EM coupling)I capacitive: BPMs, all sorts of button-style pick-upsI magnetic sensors: SQUIDs, Magneto-resistive sensors, CCCs,

nDCCT

I intercepting - direct interaction with the beam

→ absorption of significant part of the energyI Faraday cups (beam stoppers), SEM grids, screens, Ionisation

chambersI even Wire scanners can provide intensity

PART II

What measurement methods are available?

A) Non-DC beam current measurementsWhat is needed to get the beam signal?

How to process the beam signal?Calibration?

B) DC beam current measurementsDCCT and its calibration

MR sensors

PART II

What measurement methods are available?A) Non-DC beam current measurements

What is needed to get the beam signal?How to process the beam signal?

Calibration?

B) DC beam current measurementsDCCT and its calibration

MR sensors

PART II

What measurement methods are available?A) Non-DC beam current measurements

What is needed to get the beam signal?How to process the beam signal?

Calibration?

B) DC beam current measurementsDCCT and its calibration

MR sensors

Non-DC: What is needed to get the beam signal

14

A) Non-DC beam current measurements

We might use these to get the beam signal:

Faraday cupsBPMs and capacitive pick-ups

WCMsFBCTs

Note:Faraday cups measure down to DC as well, but ...

Non-DC: What is needed to get the beam signal

15

A) Non-DC beam current measurements

We might use these to get the beam signal:

Faraday cupsBPMs and capacitive pick-ups

WCMsFBCTs

Note:Faraday cups measure down to DC as well, but ...

Faraday cups

16

Measurement of low to mA currents

Ibeam

Rl Vout ≈ Rl · Ibeam

Long transmission line

I → U

Faraday cup

Ibeam

Rl Vout ≈ Rl · Ibeam

Long transmission line

I → U

Faraday cup

Provides pA resolution with excellent absolute accuracy

Faraday cups

17

Generated secondary particles can escape the cup

Ibeam

Rl Vout ≈ Rl · Ibeam

Long transmission line

I → U

Faraday cup

Ibeam

Rl Vout ≈ Rl · Ibeam

Long transmission line

I → U

Faraday cup

Install longer cup, or ...

Faraday cups

18

Generated secondary particles can escape the cup

Ibeam

Rl Vout ≈ Rl · Ibeam

Long transmission line

I → U

HV

Electrostatic deflector

Ibeam

Rl Vout ≈ Rl · Ibeam

Long transmission line

I → U

HV

Electrostatic deflector

deflect them back using HV higher than mean SE energy

Implementations

19

SE deflection using electrostatic shieldingSE deflection using electrostatic shielding

SE deflection using electrostatic shieldingSE deflection using electrostatic shielding

I USR/FLAIR anti-protonstorage

I mainly for proton beams

I p− measurements limited dueto 100 MeV+ p-p−

annihilation

I 1 µA down to fA, res. < 5 fA

Harasimowicz, J. et al., BIW2010

Properties

20

Extremely accurate measurements down to pA levels, used asabsolute calibration standard

I cup heat-load with intense beams require active cooling

I emission of secondary particles

I may have problems with attraction of particles flying around(e.g. electron showers)

Signal transmission bandwidth in hundreds of MHz. For electronmachines/fine beam structures appropriate HIBW connection tothe current meter must be provided to tens of GHz

→ Fast Faraday Cups (FFC), e.g. ELETTRA

FFC principle of operation

21

2.4mm Vacuum Feedthrough

Beam attenuators

Bellows for Fine Tuning

Faraday Cup

Stripline Circuit

C. Deibele, Fast Faraday Cup, SNS

2.4mm Vacuum Feedthrough

Beam attenuators

Bellows for Fine Tuning

Faraday Cup

Stripline Circuit

C. Deibele, Fast Faraday Cup, SNS

Ferianis., M. et al. DIPAC 2003Up to 40 GHz transmission bandwidth

Implementations

22

C. Deibele, Fast Faraday Cup, SNSC. Deibele, Fast Faraday Cup, SNS

Non-DC: What is needed to get the beam signal

23

We might use these to get the beam signal:

Faraday cupsBPMs and capacitive pick-ups

WCMsFBCTs

Wall image current

24

Any moving charged particle is accompanied with EM field:

FWHM ≈ 1.4a

γ

l [m]

λb[C

m−1]

2av

r [mm]

B[T]

Skin depth dependent

Distribution of the mirror charge and flux lines

FWHM ≈ 1.4a

γ

l [m]

λb[C

m−1]

2av

r [mm]

B[T]

Skin depth dependent

Distribution of the mirror charge and flux lines

E field looks as a pillbox for relativistic speeds and causes a chargedeposit on the inner wall of the vacuum chamber. Depositedcharge moves with particle and generates current = Wall ImageCurrent (WIC). B field gets attenuated

Non-intercepting & Wall image current

25

As beam signal is “the source” of the information about the beamcharge, we need to intercept it

I couple to EM field produced by the beam currentI diverge the wall image currentI install the detector in the vacuum chamber

I Why?I Electric field: cancelledI Magnetic field: Attenuation by ≈ 8.7 dB by one skin-depth

length: non-magnetic conductor→ δ =√10·1032π

√ρf :

1 kHz 10 kHz 100 kHz 1 MHz 10 MHz

Copper [mm] 2.1 0.66 0.21 0.066 0.021

I 3mm copper tube: A≈50 dB @ 10MHzI radio with ≈30dB dynamic range to intercept weakest beam

signal attenuated by 50 dB?

Non-intercepting & Wall image current

26

As beam signal is “the source” of the information about the beamcharge, we need to intercept it

I couple to EM field produced by the beam currentI diverge the wall image currentI install the detector in the vacuum chamber

I Why?

I Electric field: cancelledI Magnetic field: Attenuation by ≈ 8.7 dB by one skin-depth

length: non-magnetic conductor→ δ =√10·1032π

√ρf :

1 kHz 10 kHz 100 kHz 1 MHz 10 MHz

Copper [mm] 2.1 0.66 0.21 0.066 0.021

I 3mm copper tube: A≈50 dB @ 10MHzI radio with ≈30dB dynamic range to intercept weakest beam

signal attenuated by 50 dB?

Non-intercepting & Wall image current

27

As beam signal is “the source” of the information about the beamcharge, we need to intercept it

I couple to EM field produced by the beam currentI diverge the wall image currentI install the detector in the vacuum chamber

I Why?I Electric field: cancelledI Magnetic field: Attenuation by ≈ 8.7 dB by one skin-depth

length: non-magnetic conductor→ δ =√10·1032π

√ρf :

1 kHz 10 kHz 100 kHz 1 MHz 10 MHz

Copper [mm] 2.1 0.66 0.21 0.066 0.021

I 3mm copper tube: A≈50 dB @ 10MHzI radio with ≈30dB dynamic range to intercept weakest beam

signal attenuated by 50 dB?

Capacitive pick-up

28

is(t)

Vo(t) R

ba

C

h

ib(t)

+++++--------

+++++--------

Principle of capacitive pick-up

is(t)

Vo(t) R

ba

C

h

ib(t)

+++++--------

+++++--------

Principle of capacitive pick-up

I conductive electrode subjected to charge deposit → chargeflows through R

I RC filter limits the BW (C includes cables if electrodeimpedance not matched!)

I split the electrodes and you get capacitive BPM

Capacitive pick-up

29

I sensitivity ≈ 10 nV/nA, resolution down to 20 pA/e

I Intensity measurement using sum signal:∫v(t)dt = Q · Z2 · Φ

2πI sum suppresses first order position dependenceI using math third and fifth order can be eliminated as well, but:

Pick-up electrode size mattersPick-up electrode size matters

I Pickups/BPMs are many. Averaging over a ring increasesresolution (e.g. ESFR storage ring 224 BPMs factor of 15,Scheidt, MOPD64)

Button pick-up

30

Possible realisationsPossible realisations

Non-DC: What is needed to get the beam signal

31

We might use these to get the beam signal:

Faraday cupsBPMs and capacitive pick-ups

WCMsFBCTs

To measure intensity using WCMs

32

is(t) R

ib(t)

Ceramics insertion

vs(t)

2a

FWHM ≈ 1.4a

γ

LHF

LLF

Cgap

Wall Current Monitor

is(t) R

ib(t)

Ceramics insertion

vs(t)

2a

FWHM ≈ 1.4a

γ

LHF

LLF

Cgap

Wall Current Monitor

I Direct measurement of a wall current

I Bandwidth from few kHz to tens GHz range (e.g. RHIC 3 kHzto 6 GHz, Cameron, PAC99)

Practical implementation ...

33

WCM for CERN CTF3, Odier, P. DIPAC2003, D’Elia, EPAC08WCM for CERN CTF3, Odier, P. DIPAC2003, D’Elia, EPAC08

I BW≈100kHz-20GHzI Ferrite to diverge LF via external bypassI signal from 8 feedthroughs combined using resistive combiners

Practical implementation ...

34

Suwada, T., KEKSuwada, T., KEK

I 2.5Ω ceramics resistance (Alumina+carbon powder)I 4 pick-up electrodes + combinerI up to 2.5GHz BW

Non-DC: What is needed to get the beam signal

35

We might use these to get the beam signal:

Faraday cupsBPMs and capacitive pick-ups

WCMsFBCTs

To measure intensity using FBCTs

36

R0

Ns

RF connection

Measurement output

ib(t)

Ceramic gapNp

50ΩCalibration input

Fast Beam Current Transformer

R0

Ns

RF connection

Measurement output

ib(t)

Ceramic gapNp

50ΩCalibration input

Fast Beam Current Transformer

I Bandwidth from few Hz to GHz rangeI typ. resolution 2-5 pC, but sub pC optimisations ongoing

(< 1 pC see Werner, MOPD65)I measurement winding optimised to match cable on HFI Not always High-µ material (ex. Reeg, H., GSI, FCT using

Ferroxcube 3E25, τ ≈ 1 µs)

To measure intensity using FBCTs

37

ib(t)

Ls = L0 · n2

R

CVc

I(t) = c1e−λ1t + c2e

−λ2t, λ1,2 =R

2Ls±

√√√√√√√R2

4L2s

− 1

LsC

is(t)

1 : n

FBCT equivalent lumped circuit

ib(t)

Ls = L0 · n2

R

CVc

I(t) = c1e−λ1t + c2e

−λ2t, λ1,2 =R

2Ls±

√√√√√√√R2

4L2s

− 1

LsC

is(t)

1 : n

FBCT equivalent lumped circuit

Works as RLC circuit, can be used in two measurement modes:

I R2

4L2s− 1

LsC> 0: time constant τ = Ls/R,

Is = Ib/n→integrated signal related to charge

I R2

4L2s− 1

LsC< 0: C charged during pulse, then resonant

discharge→ discharge amplitude proportional to # of charges(e.g. Clarke-Gayther, EPAC96)

Practical implementation ...

38

Resonant-mode FBCT:

Reeg, H., Resonant mode BCT for GSI HEBT linesReeg, H., Resonant mode BCT for GSI HEBT lines

I peak detector to detect the voltage over capacitorI 4 dynamic ranges down to 10 pC resolution

I offset/zero value fluctuations due to noise rectification of thepeak detector circuit

I precision of calibration due to uncertain coupling efficiency ofsingle turn cal. winding

Non-DC: What is needed to get the beam signal

39

We have used one of these to get the beam signal:

Faraday cupsBPMs and capacitive pick-ups

WCMsFBCTs

and we get this ...

Missing DC component must be compensated

t [ns/µs]

I b[A]

Beam signal provided by above devices, τ short wrt beam repetition

Missing DC component must be compensated

t [ns/µs]

I b[A]

Beam signal provided by above devices, τ short wrt beam repetition

and then we have to process it by the electronics ...

Non-DC: processing electronics

40

like this ... (electronics guy prefers FPGA over Matlab)

Numericprocessing

BLRADC ApplicationFPGA

Memory

VME64xcontroller

Signal processing

Numericprocessing

BLRADC ApplicationFPGA

Memory

VME64xcontroller

Signal processing

Note: BLR = Base Line RestorerThis method work only if sampling rate is appropriate.

Non-DC: processing electronics

41

ADC BLR

Dynamic rangenon-linearity

residual offsetslew-rate and BW

Dynamic rangeINL & DNL

sampling rateresolution

Based on beamtemporalproperties

(e.g. bunch pattern)

NOISESystematic

ApplicationFPGA

Memory

VME64xcontroller

Signal processing

ADC BLR

Dynamic rangenon-linearity

residual offsetslew-rate and BW

Dynamic rangeINL & DNL

sampling rateresolution

Based on beamtemporalproperties

(e.g. bunch pattern)

NOISESystematic

ApplicationFPGA

Memory

VME64xcontroller

Signal processing

Base line restorer must be based on temporal properties of thebeam: one must know, where the beam cannot be. However,working with integrated value makes restoration more difficult →maybe doing that before integration is a good idea ...

BTW: this is the LHC FBCT system

Non-DC: processing electronics

42

ADCBLR

Dynamic rangenon-linearity

residual offsetslew-rate and BW

Dynamic rangeINL & DNL

sampling rateresolution

NOISESystematic

ApplicationFPGA

Memory

VME64xcontroller

Signal processing

ADCBLR

Dynamic rangenon-linearity

residual offsetslew-rate and BW

Dynamic rangeINL & DNL

sampling rateresolution

NOISESystematic

ApplicationFPGA

Memory

VME64xcontroller

Signal processing

BLR & integrator are analogue processing blocks, difficult to tune...

Non-DC: analogue BLR example

43

Schottky diode based analogue BLRSchottky diode based analogue BLR

t[ns]

t[ns]

t[ns]

Vc(t)

Von(t)

Vt(t)

Sampling points

BLR signals

t[ns]

t[ns]

t[ns]

Vc(t)

Von(t)

Vt(t)

Sampling points

BLR signals

Non-DC: analogue integrator example

44

Clockand

synchronisation

Beam synchronous timing

CfRg

−

+

Vout = −∫ t0

Vin

RgCf± VIQ1 ∓ VIQ2

Vin ADCIib & Vio

compensation

MOSFETdriver

VIQ2

Ccomp

MOSFET driver

VIQ1

CfRg

−

+

Vout = −∫ t0

Vin

RgCf± VIQ1 ∓ VIQ2

Iib & Vio

compensation

MOSFETdriver

VIQ2

Ccomp

MOSFET driver

VIQ1

ADC

FPGAprocessingof

twoparalleldatastream

s

Streaming data integration

Clockand

synchronisation

Beam synchronous timing

CfRg

−

+

Vout = −∫ t0

Vin

RgCf± VIQ1 ∓ VIQ2

Vin ADCIib & Vio

compensation

MOSFETdriver

VIQ2

Ccomp

MOSFET driver

VIQ1

CfRg

−

+

Vout = −∫ t0

Vin

RgCf± VIQ1 ∓ VIQ2

Iib & Vio

compensation

MOSFETdriver

VIQ2

Ccomp

MOSFET driver

VIQ1

ADC

FPGAprocessingof

twoparalleldatastream

s

Streaming data integration

Well, very complex for such small thing as integrator

Devices calibration

45

Faraday cups electronics chain calibration by DC currentPickups compared to DCCTs or FBCTs, or to Faraday cupWCMs compared to DCCTs or FBCTs, or to Faraday cupFBCTs absolute calibration using current or charge source

Matching the measurement result with known current/chargepermits to calculate gain.DC current sources of no-use for FBCTs → require pulsed source,calibration signal discharged into calibration turn.

t [µs]

V [V ]

∆t

NP =∫∆t0 i(t)dt

e = C·Vce = k · 〈acquired value〉

Charge mode calibration

Vc

t [µs]

I [mA]

∆t

Ic

NP = Ic·∆te = k · 〈acquired value〉

Current mode calibration

Two pulse-mode calibration methods

t [µs]

V [V ]

∆t

NP =∫∆t0 i(t)dt

e = C·Vce = k · 〈acquired value〉

Charge mode calibration

Vc

t [µs]

I [mA]

∆t

Ic

NP = Ic·∆te = k · 〈acquired value〉

Current mode calibration

Two pulse-mode calibration methods

Absolute accuracy of 1 to 5 % of the measurement full scale.

Pulsed current source

46

for those interested, e.g.:

VHV

HV off

ADC

HV

Lx

RlRel

Rc

Cc

Rd

Q2Q1

ADC

Ic

Rm

IcalibVcalib

LoadInPrecharge

Rc

Cc

t[ns]

ILx[A]

Pulsed current sink

VHV

HV off

ADC

HV

Lx

RlRel

Rc

Cc

Rd

Q2Q1

ADC

Ic

Rm

IcalibVcalib

LoadInPrecharge

Rc

Cc

t[ns]

ILx[A]

Pulsed current sink

Calibration by charge

47

for those interested:

t[ns]

iLx[A]

Q = Cc ·HV

VHV

HV off

ADC

HV

Q2

LoadIn

Rc

Cc

Lx

RlRel

Charge-type calibrator

t[ns]

iLx[A]

Q = Cc ·HV

VHV

HV off

ADC

HV

Q2

LoadIn

Rc

Cc

Lx

RlRel

Charge-type calibrator

Concluding Non-DC electronics components

48

There are of course other methods how to obtain the chargeinformation from the beam signal acquired by discussed devices,e.g.:

I observation of initial amplitude of resonant-mode transformer

I observation of specific harmonic frequency of the beam

I integrating current transformer (e.g. Vos., SL/94-18, CERN)

I dark current monitor (see today’s talk of D. Lipka, WEOC03)

See the references section at the end of this presentation ...

PART II

What measurement methods are available?A) Non-DC beam current measurements

What is needed to get the beam signal?How to process the beam signal?

B) DC beam current measurementsHow DCCTs and Magneto-resistance sensors work

DCCT - principle of operation

50

t

B[T ] B[T ]

H [Am−1] H [Am−1]

−Imod[A] Imod[A]

t[s]

t[s]

|A| |A|

1 3 5 7 f

fmod

f

fmod

1 3 5 72 4 6

Vmod[V ]

~

+

-

+

-

+ -

+

-

f2

Ib = q · pulse length

βc

f1

I/V generator

Vdc

Idc

Ib = 0 Ib > 0

Saturationthreshold

Harmonics production

DCCT: principle of operation

t

B[T ] B[T ]

H [Am−1] H [Am−1]

−Imod[A] Imod[A]

t[s]

t[s]

|A| |A|

1 3 5 7 f

fmod

f

fmod

1 3 5 72 4 6

Vmod[V ]

~

+

-

+

-

+ -

+

-

f2

Ib = q · pulse length

βc

f1

I/V generator

Vdc

Idc

Ib = 0 Ib > 0

Saturationthreshold

Harmonics production

DCCT: principle of operation

DCCT design issues

51

I Modulation current/voltage:I what signal: triangular, sine, squareI high voltage/current amplitude to drive cores into saturationI generator signal purity (minimise even components of fmod)

when non-linear loadI Choice of modulation frequency limits the modulator BW:

I crystalline material (NiFe): few hundreds HzI amorphous/nanocrystalline material (Fe, Co-based): few kHz

I Magnetic material used:I µr ≥ 50000

I low BH curve area

I low coercive fieldHc ≈ 1 A/m

I wound using combinationof mg. material + Mylar(typ. 20/5 µ ratio) tominimise eddy currentlosses

I low magnetostriction

I small magnetic domains tominimise Barkhausen noise

B-H granularity ! mg. domains sizeB-H granularity ! mg. domains size

DCCTs usage & limitations

52

To be used for precise DC current measurements

I measures everything: debunched, ghost and satellites,circulating beams

I due to feedback linear over 6 decades

I FS=〈10mA; 100A〉, resolution down to 1 µA, BW≤50 kHz

Calibration mostly using commercial DC current sources:

I Yokogawa GS200: accuracy ±0.03 % of setting + 5 µA

I Keithley 224: accuracy ±0.05 % of setting + 10 µA on 20 mA

Development heading to resolve:

I offset suppression & temp. dependence (≈ 5 µ A/K)

I material procurement

DCCT - material procurement is fancy stuff

53

H. Reeg: B-H curve measurements, Vitrovac 6025FH. Reeg: B-H curve measurements, Vitrovac 6025F

Vitrovac ordered with the same specification at different time.(VacuumSchmelze production technology didn’t change!)

Interesting study: MR sensors

54

Usage of magneto-resistance (GMR, AMR) andmagneto-impedance sensors to get the beam info: GSI novel-DCCT

Hape, M. et al., DIPAC2005Hape, M. et al., DIPAC2005

Beam currents in hundreds-A range, clip-on configuration

Invite you to see next talk by Wolfgang Vodel

Overview on Cryogenic Current Comparators for Beam Diagnostics

THANK YOU FOR YOUR ATTENTION

This presentation would not be possible without kind participation of manypeople around the world - thanks a lot:

P. Cameron, M. Heron, K. Scheidt, H. Reeg, D. Lipka, P. Forck, M. Wendt,A. Peters, M. A. Ibrahim, M. Wilinski, W. Vodel, P. Odier, S. Smith,

M. Ferianis, E. C. Deibele, M. Werner, K. Wittenburg

PART III

References used

Faraday cups

57

I Yu. Antipov et al.: “THE COMPACT FARADAY CUP FOR RADIOBIOLOGICAL RESEARCHES IN IHEPACCELERATORS BEAMS”, Institute for High Energy Physics, Protvino, Moscow region, Russia

I J. Harasimowicz, C. P. Welsch: “FARADAY CUP FOR LOW-ENERGY, LOW-INTENSITY BEAMMEASUREMENTS AT THE USR”, Cockcroft Institute, Warrington WA4 4AD, UK, and Department ofPhysics, University of Liverpool, Liverpool L69 7ZE, UK.

I T. Houck et al.: “FARADAY CUP MEASUREMENTS OF THE PLASMA PLUME PRODUCED AT ANX-RAY CONVERTER”, Lawrence Livermore National Laboratory, Livermore, California 94550 USA

I A.F.D. Morgan: “DESIGN OF THE FARADAY CUPS IN DIAMOND”, Diamond Light Source, UK

Wall Current Monitors

58

I T. Suwada et al.: “RECALIBRATION OF A WALL-CURRENT MONITOR USING A BEAM-INDUCEDFIELD FOR THE KEKB INJECTOR LINAC”, KEK, 1-1 Oho, Tsukuba-shi, Ibaraki-ken, 305, Japan

I A. D’Elia et al: “HIGH BANDWIDTH WALL CURRENT MONITOR FOR CTF3”, CERN, Geneva,Switzerland

I P. R. Cameron et al.: “THE RHIC WALL CURRENT MONITOR SYSTEM” , BNL, FNAL, USA

I A. D’Elia et at: “High Bandwidth Wall Current Monitor”, EUROTEV report, September 1, 2008

I C. D. Moore et al.: “Single Bunch Intensity Monitoring System Using an Improved Wall Current Monitor”,FERMI, USA

Fast Beam Current Transformers

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I A. Burns et al.: “NOISE REDUCTION ON THE LEP BUNCH CURRENT MEASUREMENT SYSTEM”,CERN, CH–1211 Geneva 23, Switzerland

I Michael A. Clarke-Gayther: “A HIGH STABILITY INTENSITY MONITORING SYSTEM FOR THE ISISEXTRACTED PROTON BEAM”, RAL, Didcot, United Kingdom

I A. Higashiya et al.: “DEVELOPMENT OF A BEAM CURRENT TRANSFORMER FOR THE X-FELPROJECT IN SPRING-8”, SPring-8, JAPAN

I H. Reeg et al.: “CURRENT TRANSFORMERS FOR GSI’S KEV/U TO GEV/U ION BEAMS - ANOVERVIEW”, GSI, Germany

I M. Kesselman et al.: “BEAM CURRENT MONITOR CALIBRATOR FOR THE SPALLATION NEUTRONSOURCE”, Brookhaven National Laboratory, Upton NY 11973, USA

DCCTs

60

CARE-N3 EU sponsored workshop on DC current transformers, in particular:

I P. Odier: “DCCT TECHNOLOGY REVIEW”, CARE Workshop, Lyon, France

Intensity measurements talks

61

I Robert C. Webber: “Tutorial on Beam Current Monitoring”

I F. Gougnaud et al.: “THE FIRST STEPS OF THE BEAM INTENSITY MEASUREMENT OF THESPIRAL2 INJECTOR”, CEA, IRFU, SIS / Saclay, France

Other Intensity Measurements

62

I C. R. Rose et al.: “DESCRIPTION AND OPERATION OF THE LEDA BEAM-POSITION / INTENSITYMEASUREMENT MODULE”, Los Alamos National Laboratory, Los Alamos, NM 87545

I A.G.Afonin et al.: “WIDE RANGE EXTRACTED BEAM INTENSITY MEASUREMENT AT THE IHEP”,IHEP, Protvino, Russia

I R. Thirman-Keup et al.: “MEASUREMENT OF THE INTENSITY OF THE BEAM IN THE ABORT GAPAT THE TEVATRON UTILIZING SYNCHROTRON LIGHT”, FNAL, Batavia, IL 60510, USA

I P.-A. Duperrex et al.: “CURRENT AND TRANSMISSION MEASUREMENT CHALLENGES FOR HIGHINTENSITY BEAMS”, PSI, Villigen, Switzerland

I T.J. Ma et al.: “BUNCH-BY-BUNCH BEAM CURRENT MONITOR FOR HLS”, NSRL, School of NuclearScience and Technology, University of Science and Technology of China, Hefei 230029, P. R. China

I M. Dehler et al.: “STRIPLINE DEVICES FOR FLASH AND EUROPEAN XFEL”, PSI, Switzerland,DESY, Hamburg, Germany

I P. Moritz et al.: “Diamond Detectors with Subnanosecond Time Resolution for Heavy Ion SpillDiagnostics”, GSI, Germany

Squids / MR sensors

63

I T. Sieber et al.: “INTENSITY AND PROFILE MEASUREMENT FOR LOW INTENSITY ION BEAMS INAN ELECTROSTATIC CRYOGENIC STORAGE RING”, MPI-K Heidelberg, Germany

I M. Schwickert et al.: “BEAM DIAGNOSTIC DEVELOPMENTS FOR FAIR”, GSI, Darmstadt, Germany

I Markus Hape et al.: “HIGH DYNAMIC MAGNETIC BEAM CURRENT MEASUREMENTS BY MEANSOF OPTIMISED MAGNETO-RESISTANCE (MR) SENSOR ENGINEERING”, GSI Darmstadt, Germany

I W. Vodel et al.: “CURRENT STATUS OF THE SQUID BASED CRYOGENIC CURRENTCOMPARATOR FOR ABSOLUTE MEASUREMENTS OF THE DARK CURRENT OFSUPERCONDUCTING RF ACCELERATOR CAVITIES”, DESY Hamburg, Germany

I A. Peters et al.: “RECENT IMPROVEMENTS OF A CRYOGENIC CURRENT COMPARATOR FOR nAION BEAMS WITH HIGH INTENSITY DYNAMICS”, GSI, Darmstadt, Germany

I T. Watanabe et al.: “DEVELOPMENT OF BEAM CURRENT MONITOR WITH HTS SQUID AND HTSCURRENT SENSOR”, RIKEN Nishina Center for Accelerator-Based Science, Wako-shi, Saitama 351-0198Japan

I T.Tanabe et al.: “A CRYOGENIC CURRENT MEASURING DEVICE FOR THE LOW-INTENSITY BEAMAT THE STORAGE RING TARN II”, KEK, Tanashi, Tokyo, Japan

I T. Watanabe et al.: “DEVELOPMENT OF BEAM CURRENT MONITOR WITH HIGH-Tc SQUID ATRIBF”, RIKEN Nishina Center for Accelerator-Based Science, Wako-shi, Saitama 351-0198, Japan

PART IV

Extras

Intensity measurements during LHC orbit bump

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DCCTFBCT, varies by ≈1 %/mm with respect to the DCCT

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×1011 LHC Beam 2 Intensity measurement during the orbit bump

DCCTFBCT, varies by ≈1 %/mm with respect to the DCCT

≈1 %/mm bunch position dependency of the FBCT toroid