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