sps kicker-magnet outgassing with different bunch spacing's

1 ECLOUD Workshop: Nov. 20-21, 2008

Mike Barnes, AB/BT

SPS Kicker-Magnet SPS Kicker-Magnet Outgassing with Different Outgassing with Different

Bunch Spacing'sBunch Spacing's

M.J. Barnes, E. Mahner & V. Senaj

Acknowledgements:V. Baglin, E. Benedetto, F. Caspers, E. Chapochnikova,

K. Cornelis, L. Ducimetière, G. Papotti, G. Rumolo


Mike Barnes, AB/BT

II. Overview of PresentationOverview of Presentation

• Brief description of a kicker magnet; • During MD of August 12th to 14th, 2008 interlocks (trips) due to pressure rise, with 50ns beam, at MKDV1 and ion traps.

• Summary, for SPS kicker magnets, of temperature and pressure;

• Significant temperature rise of some kicker magnets noted, at some bunch spacing's; this is thought to be understood and independent of out-gassing;• Out-gassing summary for a bunch spacing of 25ns, 50ns or 75ns.

• During MD of October 6th to 8th, 2008 pressure rise-noted at MKDV1, but no trips (however, interlocks due to ion traps).

• Summary of out-gassing for SPS kicker magnet, from MD, of high resolution vacuum measurements.

• Overall summary.


Mike Barnes, AB/BT

PS

LHC

SPS

PS ComplexPS

LHC

SPS

PS Complex

30 x MKD

12 x MKBV

8 x MKBH

MKQH

2 x MKDV

3 x MKDH

MKQV

5 x MKE

4 x MKQAV

4 x KKQAH

4 x MKQAV

4 x KKQAH

4 x MKI4 x MKI

30 x MKD

12 x MKBV

8 x MKBH

4 x MKI

4 x MKE5 x MKE4

MKQH

2 x MKDV

3 x MKDH

MKQV

3 x MKE6

4 x MKP

PS

LHC

SPS

PS ComplexPS

LHC

SPS

PS ComplexPS

LHC

SPS

PS ComplexPS

LHC

SPS

PS Complex

30 x MKD

12 x MKBV

8 x MKBH

MKQH

2 x MKDV

3 x MKDH

MKQV

5 x MKE

4 x MKQAV

4 x KKQAH

4 x MKQAV

4 x KKQAH

4 x MKQAV

4 x KKQAH

4 x MKQAV

4 x KKQAH

4 x MKI4 x MKI4 x MKI4 x MKI

30 x MKD

12 x MKBV

8 x MKBH

4 x MKI

4 x MKE5 x MKE4

MKQH

2 x MKDV

3 x MKDH

MKQV

3 x MKE6

4 x MKP

SPS & SPS & LHCLHC KICKER SYSTEMS KICKER SYSTEMS


Mike Barnes, AB/BT1 cell

Simplified view of a transmission Simplified view of a transmission line kicker magnet line kicker magnet

Transition pieces, between magnet tank and magnet frame, installed in some kicker magnets.

MKE magnet:

FERRITE

Return Conductor

Go Conductor

Vap

Hap

Cross-Section of MKDV1 (Vertical) ApertureMKDV1:

Pumps

Pressure Gauge

Pipe: ~16cm ID & ~49cm long


Mike Barnes, AB/BT

SUMMARY OF SPS KICKER SUMMARY OF SPS KICKER APERTURES & MATERIALSAPERTURES & MATERIALS

SPS

KICKER

COMMENTS Hap (mm) Vap (mm) MAGNETIC MATERIAL

Max. Pressure [MD Aug 2008] (1s

resolution)

MKP-SMKP-L

Beryllium for return cond.

101141

6154

8C11 Ferrite8C11 Ferrite

Not significantly: ~2e-8mbar

MKQH Inserts with Silver paint

135 33.9 8C11 Ferrite 75ns beam: ~3e-7mbar

MKQV 56 102 8C11 Ferrite 50ns beam: ~2e-7mbar

MKDV1A

MKDV25656

7583

8C11 Ferrite8C11 Ferrite

50ns beam: ~1e-6mbar50ns beam: ~7e-7mbar

MKDH1/2MKDH3

Glass fibre 96105

5660

Laminated Si SteelLaminated Si Steel

50ns beam: ~1e-7mbar50ns beam: ~5e-8mbar

MKE-SMKE-L

Silver/Glass stripes for L10

135147.7

3235

8C11 Ferrite8C11 FerriteB

MKE6 (50ns):~4e-7mbarMKE4 No: : ~3e-8mbar

Aluminium (Anticorodal 110) generally used for conductors.A Remnant field estimated to be <1 G for 8C11 and ~5G for 4E2;B Except “L9” @ MKE6 4E2 ferrite (higher degassing rate than 8C11) FERRITE

Vap

Hap


Mike Barnes, AB/BT

MKDV Temperature & Pressure on 12, MKDV Temperature & Pressure on 12, 13 & 1413 & 14thth August 2008 August 2008

0.0E+00

5.0E-08

1.0E-07

1.5E-07

2.0E-07

2.5E-07

3.0E-07

3.5E-07

4.0E-07

4.5E-07

5.0E-07

12-08-08 0:00

12-08-08 6:00

12-08-08 12:00

12-08-08 18:00

13-08-08 0:00

13-08-08 6:00

13-08-08 12:00

13-08-08 18:00

14-08-08 0:00

14-08-08 6:00

14-08-08 12:00

14-08-08 18:00

15-08-08 0:00

Date & Time

Pre

ss

ure

(m

ba

r)

26

28

30

32

34

36

38

40

42

44

46

Te

mp

era

ture

(C

)

MKDV1: pressureMKDV2: pressureMKDV1: TemperatureMKDV2: Temperature

25ns beam

3 batches 50ns beam @ 01:43:immediate trip

50ns beam 05:13 to 07:00

75ns beam to 01:30

Normally: MKDV1 temperature>MKDV2 and pressure < 6e-8 mbar (as per 25ns beam);

For 75ns beam MKDV2 temperature > MKDV1 and pressure < 6e-8 mbar;

For 50ns beam MKDV temperature is not an issue, but pressure is an issue!.

8s resolution for pressure.

See next 2 slides.

8s resolution:

Note: Ecloud monitors show maximum Ecloud with 25ns bunch spacing.


Mike Barnes, AB/BT

MKDV Pressure on 14/08/2008, MKDV Pressure on 14/08/2008, between 01:20hrs & 02:10hrs.between 01:20hrs & 02:10hrs.

0.00E+00

1.00E-07

2.00E-07

3.00E-07

4.00E-07

5.00E-07

6.00E-07

7.00E-07

8.00E-07

9.00E-07

1.00E-06

14-08-08 1:20

14-08-08 1:25

14-08-08 1:30

14-08-08 1:35

14-08-08 1:40

14-08-08 1:45

14-08-08 1:50

14-08-08 1:55

14-08-08 2:00

14-08-08 2:05

14-08-08 2:10

Date & Time

Pre

ss

ure

(m

ba

r)

26

28

30

32

34

36

38

40

42

44

46

Te

mp

era

ture

(C

)MKDV1: pressureMKDV2: pressureMKDV1: TemperatureMKDV2: Temperature

75ns beam to ~01:30

Started 1 batch 50ns beam at 1:32hrs,

continuously.

Single shot of 4 batches of 50ns beam at 2:05hrs: interlock.

One shot of 2 batches of 50ns beam at

1:42hrs.


1:43hrs: interlock.

Information from: Giulia Papotti:

Summary: 50ns beam causes pressure rise; high pressure with 3 or 4 batches per shot.

1s resolution


Mike Barnes, AB/BT

MKDV Pressure on 14/08/2008, MKDV Pressure on 14/08/2008, between 05:00hrs & 07:00hrs.between 05:00hrs & 07:00hrs.

0.0E+00

1.0E-07

2.0E-07

3.0E-07

4.0E-07

5.0E-07

6.0E-07

7.0E-07

8.0E-07

9.0E-07

14-08-08 5:00

14-08-08 5:10

14-08-08 5:20

14-08-08 5:30

14-08-08 5:40

14-08-08 5:50

14-08-08 6:00

14-08-08 6:10

14-08-08 6:20

14-08-08 6:30

14-08-08 6:40

14-08-08 6:50

14-08-08 7:00

Date & Time

Pre

ssu

re (

mb

ar)

26

27

28

29

30

31

32

33

34

35

Te

mp

era

ture

(C

)

MKDV1: pressureMKDV2: pressureMKDV1: TemperatureMKDV2: Temperature

Started 1 batch 50ns beam at 5:13hrs.


5:39hrs.

Four shots of 4 batches of 50ns beam at 5:41hrs: interlock.

Four shots of 4 batches of 50ns beam

at 5:45hrs.

Two shots of 4 batches of 50ns beam

at 5:49hrs.

Information from: Giulia Papotti:

One batch per shot of 50ns beam from

6:05hrs to 7:00hrs.

Summary: 50ns beam causes pressure rise; high pressure with 3 or 4 batches per shot.

1s resolution


Mike Barnes, AB/BT

SPS Kickers: Vacuum, August SPS Kickers: Vacuum, August 14, 200814, 2008

August 14, 2008

0.0E+00

1.0E-07

2.0E-07

3.0E-07

4.0E-07

5.0E-07

6.0E-07

7.0E-07

8.0E-07

9.0E-07

1.0E-06

0:000:30

1:001:30

2:002:30

3:003:30

4:004:30

5:005:30

6:006:30

7:00

Time

Pre

ss

ure

(m

ba

r)

MKDV1

MKDV2

MKE6: August 14, 2008

0.0E+00

5.0E-08

1.0E-07

1.5E-07

2.0E-07

2.5E-07

3.0E-07

3.5E-07

4.0E-07

0:000:30

1:001:30

2:002:30

3:003:30

4:004:30

5:005:30

6:006:30

7:00

Time

Pre

ss

ure

(m

ba

r)

MKE1 (serigraphed)

MKE2 (No cells serigraphed)

MKE3 (2 cells serigraphed)

75ns beam

3 batches, 50ns 4 batches, 50ns

4x4 batches, 50ns

50ns beam

August 14, 2008

0.0E+00

1.0E-08

2.0E-08

3.0E-08

4.0E-08

5.0E-08

6.0E-08

7.0E-08

8.0E-08

9.0E-08

1.0E-07

0:301:00

1:302:00

2:303:00

3:304:00

4:305:00

5:306:00

6:307:00

Time

Pre

ss

ure

(m

ba

r)

MKDH1

MKDH2

MKDH3

75ns beam

75ns beam


4 batches, 50ns3 batches, 50ns

4x4 batches, 50ns

4x4 batches, 50ns

50ns beam

50ns beam

MKDV1: Hap=56mm, Vap=75mmMKDV2: Hap=56mm, Vap=83mm

MKDH1: Hap=96mm, Vap=56mmMKDH2: Hap=96mm, Vap=56mmMKDH3: Hap=105mm, Vap=60mm

MKE1: Hap=147.7mm, Vap=35mmMKE2: Hap=147.7mm, Vap=35mmMKE3: Hap=135mm, Vap=32mm

Transition pieces Ferrite

No transition piecesFerrite

No transition pieces.0.35mm laminated steelNo temperature probes.

1s resolution

- 4E2 ferrite, 1 of 2

pumps inoperative

0.00E+00

1.00E-08

2.00E-08

3.00E-08

4.00E-08

5.00E-08

6.00E-08

7.00E-08

8.00E-08

9.00E-08

Time

Pre

ss

ure

(m

ba

r)

MKE1MKE2MKE3MKE4MKE5

75ns beam

3 batches, 50ns

4 batches, 50ns 4x4 batches, 50ns

50ns beam

MKE1: Hap=147.7mm, Vap=35mmMKE2: Hap=147.7mm, Vap=35mmMKE3: Hap=135mm, Vap=32mmMKE4: Hap=135mm, Vap=32mmMKE5: Hap=147.7mm, Vap=35mm

Transition pieces

MKE4


Mike Barnes, AB/BT

SPS Kickers: Vacuum, August SPS Kickers: Vacuum, August 14, 200814, 2008

August 14, 2008

0.0E+00

1.0E-07

2.0E-07

3.0E-07

4.0E-07

5.0E-07

6.0E-07

7.0E-07

8.0E-07

9.0E-07

1.0E-06

0:000:30

1:001:30

2:002:30

3:003:30

4:004:30

5:005:30

6:006:30

7:00

Time

Pre

ss

ure

(m

ba

r)

MKDV1

MKDV2

0.0E+00

2.0E-09

4.0E-09

6.0E-09

8.0E-09

1.0E-08

1.2E-08

1.4E-08

1.6E-08

1.8E-08

2.0E-08

0:000:30

1:001:30

2:002:30

3:003:30

4:004:30

5:005:30

6:006:30

7:00

Time

Pre

ssu

re (

mb

ar)

MKP4

MKP3

MKP2

MKP1

75ns beam

75ns beam


4 batches, 50ns

3 batches, 50ns

4x4 batches, 50ns

4x4 batches, 50ns

50ns beam

50ns beam

MKDV1: Hap=56mm, Vap=75mmMKDV2: Hap=56mm, Vap=83mm

12xMKP-S: Hap=101mm, Vap=61mm4xMKP-L: Hap=141mm, Vap=54mm

No transition piecesFerrite

1s resolution

SPS MKQ: 14th August 2008

1.0E-09

5.1E-08

1.0E-07

1.5E-07

2.0E-07

2.5E-07

0:000:30

1:001:30

2:002:30

3:003:30

4:004:30

5:005:30

6:006:30

7:00

Time

Pre

ss

ure

(m

ba

r)

MKQH (ceramic substrate for impedance reduction)

MKQV

75ns beam4 batches, 50ns

3 batches, 50ns

4x4 batches, 50ns

50ns beam

MKQH: Hap=135mm, Vap=33.9mmMKQV: Hap=56mm, Vap=102mm

MKQH less sensitive to 50ns & more sensitive to 75 bunch spacing….No temperature probes.


Mike Barnes, AB/BT

MKDV1 Kicker: Vacuum, MKDV1 Kicker: Vacuum, October 6October 6thth to 8th, 2008 to 8th, 2008

30

32

34

36

38

40

42

44

46

48

500

6/1

0 0

0:0

0

06

/10

03

:00

06

/10

06

:00

06

/10

09

:00

06

/10

12

:00

06

/10

15

:00

06

/10

18

:00

06

/10

21

:00

07

/10

00

:00

07

/10

03

:00

07

/10

06

:00

07

/10

09

:00

07

/10

12

:00

07

/10

15

:00

07

/10

18

:00

07

/10

21

:00

08

/10

00

:00

08

/10

03

:00

08

/10

06

:00

08

/10

09

:00

08

/10

12

:00

08

/10

15

:00

08

/10

18

:00

08

/10

21

:00

09

/10

00

:00

Date (2008) & Time

Tem

per

atu

re (

C)

0.0E+00

5.0E-08

1.0E-07

1.5E-07

2.0E-07

2.5E-07

3.0E-07

3.5E-07

4.0E-07

4.5E-07

5.0E-07

Pre

ssu

re (

mb

ar)

MKDV1MKDV2MKDV1

50ns

bea

m

50ns beam, intensity scan

50ns beam

450e

10

ppba

tch

75ns

be

am

23:5

5: n

om.

Inte

nsity

25ns beam

4 ba

tche

s

1 bu

nch

3 ba

tche

s

high intensity

8s resolution

See next side


Mike Barnes, AB/BT

• Volume of MKDV1 tank is ~0.3m3;• 3 ion pumps for each magnet, rated at 350 l/s each (1050 l/s total);• ideal τ for decay of pressure of 0.3s;• 3τ is ~ consistent with measurement (16cm ID, 49cm long pipes connecting to pump...).

MKDV1 Kicker: Vacuum, MKDV1 Kicker: Vacuum, October 7October 7thth, 2008: 50ns beam, 2008: 50ns beam

16ms resolution

~4s2s

21.6s supercycle

BCT data courtesy of Elena Benedetto


Mike Barnes, AB/BT

MKDV Pressure Peak versus MKDV Pressure Peak versus Bunch Intensity (4 batches)Bunch Intensity (4 batches)

50ns bunch spacing; The instantaneous pressure rises in MKDV kickers

shows a clear threshold effect with intensity.

MKDV1

MKDV2

(mba

r)

Plot courtesy of Karel Cornelis


Mike Barnes, AB/BT

SummarySummary 50ns bunch spacing causes immediate pressure rise (surface

effect-e.g. electron cloud) for both MKDV1 & MKDV2 – but MKDV1 is more significant;

Pressure rise shows an intensity threshold (>6x1010 protons/bunch);

Measured pressure rise appears to be real as pressure fall is reasonably consistent with installed pumping rate;

Pressure rise is dependent upon: Beam intensity; Number of batches; Bunch length (K. Cornelis presentation to SPSU 18/11/2008);

MKE6, MKDH, MKDH & MKQV kickers all show immediate pressure rise with 50ns bunch spacing ….. But MKQH sensitive to 75ns bunch spacing;

• But Ecloud monitors show maximum Ecloud with 25ns bunch spacing...


Mike Barnes, AB/BT

Questions & CommentsQuestions & Comments


Mike Barnes, AB/BT

MKE: Beam Coupling MKE: Beam Coupling Impedance ReductionImpedance Reduction

Beam coupling impedance is reduced using conductive stripes (serigraphy), i.e. interleaved comb structure, directly printed onto the ferrite blocks and a reliable contact to the metallic HV plates at either side;

Capacitive coupling between stripes (stripes carry beam image current).

Printed strips in MKE-L10

Interdigital comb structure 20mm spacing

surface discharge

sps kicker-magnet outgassing with different bunch spacing's

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