Towards the coating of 3 MBB dipolesStatus report

SPS-U

Coating tests on MBB 096 with liner

• Test #1– Liner 2 meters, 2 cathodes, 1 anode, sputtering power 400 W (limited by

geometry and arcs at the extremities)– Thickness non homogeneous– SEY non homogeneous as a consequence

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Test #1

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Test #1

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Coating tests on MBB 096 with liner• Test #2

– Liner 2 meters, 2 cathode, 2 anodes, sputtering power 700 W– Max temperature on liner during coating 120 °C (specified for the

vacuum chambers 150 °C at the sides, 300 °C on top)

– More uniform dark colour– SEY:

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SEY for test #2

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0.6

0.7

0.8

0.9

1.0

1.1

1.2

0 200 400 600 800 1000 1200 1400 1600 1800

energy [eV]

SEY

MBB_C80_20090216_1

MBB_C80_20090216_2

MBB_C80_20090216_3

MBB_L80_20090216_1

MBB_L80_20090216_2

MBB_L80_20080216_3

a-C on MBB 867 Liner #2 , 2 positions

Under way• Test #3

– Liner 2 meters, 2 cathodes, 2 anodes– Better insulation of and shielding of feedthroughs and of cathodes

extremities– Test for higher power sputtering and temperature limit.

• Cleaning of MBB 085 and MBB 040– Si-O-Si and HC were detected on all three dipoles before cleaning– Cleaning of MBB 096 was successful but not 100% conform to UHV

specs

• Modification of vacuum chambers– Piquages on MBB 096, 085, 040 done– Piquages to be done on MBB 51470 and QD 51510 in the tunnel (week

10, 2-6.3)– Studs for RF shields being welded on MBB 085, 040 (MBB 096 done)

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Coating plans• MBB 096

– Start assembly 19.2– Coating– Dismount 24.2 (store under N2)

• MBB 085– Start assembly 24.2– Coating– Dismount 27.2 (store under N2)

• MBB 040– Start assembly 27.2– Coating– Dismount 4.3 (store under N2)

• Last delivery date– Monday 9.3

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Sample for C magnet, coated with a-C on 1.10.2008

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0.0

0.2

0.4

0.6

0.8

1.0

1.2

0 200 400 600 800 1000 1200 1400 1600 1800

energy [eV]

SEY

SPS_2_20081001_1

SPS_2_20081001_2

SPS_2_20090217_1

SPS_2_20090217_2

SPS-SEY insertion sample, after 4 months in static vacuum

Liners

• Liner #1: inox• Liner #2: a-C coated from last year• We are still testing the Zr coating parameters for the liner #3

– Problems in temperature control for obtaining the right “rough” zirconium

• Liner #4 to be defined

• Installation schedule to be defined both for C-magnet sample and for liners

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