ATF2
Magnets
Measurements of the ATF2 FF sextupoles and status report
26th/27th August 2008
Cherrill Spencer, Magnet Designer and member of ATF2 Magnet Group
26/27th August 2008 ATF2 FF Sextupoles Msts 2
ATF2
Magnets
Reporting tonight on the last three ATF2 magnets I have responsibility for:
SF6, SF5 and SD4.
Their beamline positions are shown in the diagram above.
They will have cavity-type beam position monitors in their apertures, the BPM will be on the downstream end of the sextupole
26/27th August 2008 ATF2 FF Sextupoles Msts 3
ATF2
Magnets
Requirements for the FF sextupoles: SD4, SF5, SF6, from the V4.0 ATF2 MAD deck
Name K2L m-2 Pole at 30° (looking down beam)
Integrated Gradient’ strength
Aperture Diameter
mm
SF6 8.564562 North 37.14 T/m 40-50
SF5 -0.790868 South 3.43 T/m 40-50
SD4 14.909987 North 64.655 T/m 40-50
∫G’.dl calculated for a 1.3 GeV beam, using
K2L= 2BptLeff/r2(Bρ) and G’ = 2Bpt/ r2
26/27th August 2008 ATF2 FF Sextupoles Msts 4
ATF2
Magnets
3 OLD SLAC sextupoles chosen to be used for FF sextupoles: all same style. Will meet
requirements and have room for QBPM
Style name= 1.625SX3.53Bore diameter= 41.28 mm
Core length =89.66mm
26 turns of 0.255” sq hollow Cu conductor per coil
Used old magnets to save money
26/27th August 2008 ATF2 FF Sextupoles Msts 5
ATF2
Magnets
1.625SX3.53 after refurbishment, on magnetic measuring stand at SLAC
This is how some of the Synflex hoses will be placed: 2 inputs and 3 returns. 2 coils per water circuit.
26/27th August 2008 ATF2 FF Sextupoles Msts 6
ATF2
Magnets
FF sextupole on new support
Here are the copper power terminals
Here are some copper pipes that carry LCW & current from coil to coil
New Al support
26/27th August 2008 ATF2 FF Sextupoles Msts 7
ATF2
Magnets
Drawing of newly designed and made support. Will send copies of parts & assembly drawings to KEK.
26/27th August 2008 ATF2 FF Sextupoles Msts 8
ATF2
Magnets
Side view of 2 FF sextupoles on their new supports
Are 3 thermal switches, at exits of the 3 water circuits. This is terminal block where their wiring goes
Each sextupole has 4 tooling balls and they have been fiducialized on a CMM. Data will be sent to KEK.
26/27th August 2008 ATF2 FF Sextupoles Msts 9
ATF2
Magnets
Each magnet’s poletips were measured on a CMM. Only poles# 1&2 are removable
Terminal Side
Radial Distance (0.8125)
Actual Angle of Pole w.r.t
CSY
Deviation Angle to
Pole (act-nom)
RadiansMicro
Radians
Pole Tip Distance (1.625)
Pole Tip 1 0.81259 89.99818 -0.00182 -0.00003 32 1.62578Pole Tip 2 0.81319 270.00990 0.00990 0.00017 173Pole Tip 3 0.81307 30.00924 0.00924 0.00016 161 1.62520Pole Tip 4 0.81214 210.03683 0.03683 0.00064 643Pole Tip 5 0.81205 329.99841 -0.00159 -0.00003 28 1.62409Pole Tip 6 0.81204 150.00534 0.00534 0.00009 93
+X
+Y
0°
90°
180°
270°
26/27th August 2008 ATF2 FF Sextupoles Msts 10
ATF2
Magnets
“Non-terminal” end mechanical measurements from CMM. Tooling balls were fiducialized while on CMM.
Non Terminal
Side
Radial Distance (0.8125)
Actual Angle of Pole w.r.t
CSY
Deviation Angle to
Pole (act-nom)
RadiansMicro
Radians
Pole Tip Distance (1.625)
Pole Tip 1 0.81225 90.02671 0.02671 0.00047 466 1.62635Pole Tip 2 0.81314 269.99037 -0.00963 -0.00017 168Pole Tip 3 0.81249 30.00029 0.00029 0.00001 5 1.62468Pole Tip 4 0.81220 210.07422 0.07422 0.00130 1295Pole Tip 5 0.81211 329.98648 -0.01352 -0.00024 236 1.62525Pole Tip 6 0.81314 150.04443 0.04443 0.00078 775
Gap Nominal (0.3378)
Terminal Side
Non Terminal
Side 3-5 0.33852 0.339564-6 0.33929 0.33936
Fabrication tolerances. Aperture: 1.625+/- 0.001”
Interpole gaps: 0.3378 +/- 0.002 “
26/27th August 2008 ATF2 FF Sextupoles Msts 11
ATF2
Magnets Thermal test on FF sext SN#1, 35 amps
23
24
25
26
27
28
29
11:5
7:30
12:0
4:30
12:1
1:30
12:1
8:30
12:2
5:30
12:3
2:30
12:3
9:30
12:4
6:30
12:5
3:30
13:0
0:30
13:0
7:30
13:1
4:30
13:2
1:30
13:2
8:30
13:3
5:30
13:4
2:30
13:4
9:30
13:5
6:30
14:0
3:30
14:1
0:30
14:1
7:30
14:2
4:30
14:3
1:30
14:3
8:30
14:4
5:30
14:5
2:30
Time of temperature measurements
Var
iou
s te
mp
erat
ure
s, D
eg C
LCW at manifold (in & out)
Magnet coil (purple)
LCW supply at magnet ( Yellow)
LCW return at magnet ( light blue)
Ambient temperature
Magnet run at 35 amps for 3 hours, ∆P=118psi. At KEK will be 80 psi. Coil temperature increased by ~ 0.5ºC
26/27th August 2008 ATF2 FF Sextupoles Msts 12
ATF2
Magnets
Integrated strength measured from 0.4 to 50 amps: lower strength range than originally designed for.
Integral G'dl V current, without 0.4 & 0.83 amps
y = 2.2400x + 0.8653
R2 = 1.0000
0
20
40
60
80
100
120
0 10 20 30 40 50 60
Current, amps
Inte
gra
l G
'.dl,
Tes
la/m
IntG'.dl V I without 2 lowest I
Linear (IntG'.dl V I without 2 lowest I)
From this data on SN#1 can predict these 3 operating currents:
SD4 ~28.5 amps
SF5 ~ 1.4 amps
SF6 ~ 16 amps
Each magnet has a 50 amp PS.
Low current & low voltage of SF5 will be dealt with by adding a ~0.25ohm air-cooled resistor in series with SF5
26/27th August 2008 ATF2 FF Sextupoles Msts 13
ATF2
Magnets
Harmonics measured at the 3 nominal currents on SN#1. Quoted at 1cm radius as percentage of sextupole.
• Multipole harmonic tolerances quoted in table 3.7 in section 3.2 of the ATF2 Proposal (August 2005).
• 1st allowed harmonic = 18-pole – normal tolerance < 30.6%; skew tolerance < 3.74%
• Measured 0.018% at all 3 currents, all normal ☺• Other harmonics’ tolerances and measurements at 1.4, 16 and 27.9 A
– Octupole normal< 0.66% ; skew<0.21%
– Measured 0.11%; 0.14%, 0.14% ☺
– 10-pole normal< 3.53% ; skew< 0.48%
– Measured 0.03%; 0.008%; 0.008% ☺
– Are mixtures of normal and skew by the measured angles of their poles
• Will measure harmonics on next 2 sextupoles & send values to Glen White for him to put in his model of FF to see if effects the spot size.
26/27th August 2008 ATF2 FF Sextupoles Msts 14
ATF2
Magnets
Y coord of magnetic center as current was changed in a Beam Based Alignment Sequence of Currents
Nominal Current :16 amps, then 10.8, 12.7 and 14.5 amps
-50
-49.5
-49
-48.5
-48
-47.5
-47
-46.5
-46
-45.5
-45
8 9 10 11 12 13 14 15 16 17
Current, amps
Y c
oo
rd o
f m
agn
etic
cen
ter,
mic
ron
sMagnetic center moved by about 1 micron during the complete sequence of BBA currents.
Also true at 28 amps.
Actually the FF sextupoles will be aligned by a different method, not by changing their current.
26/27th August 2008 ATF2 FF Sextupoles Msts 15
ATF2
Magnets
Present status and predicted shipping
• 2nd sextupole on the magnetic measuring stand. Waiting on Alignment Crew to align.
• Expect to be measured by Friday 29th Aug.• 3rd sextupole will be measured next week• Crates are ready. Shipping ~ Sept 8th• LCW hoses will be made next week.• Shipping paperwork starting ( 2 sextupoles are
SLIGHTLY radioactive, just over the reporting limit). Will report details to Terunuma-san & arrange with him where to ship to
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