LCABD WP7 : Cavity BPMs

A. Aryshev, S. T. Boogert (JAI@RHUL), G. Boorman, A. Heo, Y. Honda, J.Y. Huang, S.J. Hwang, N. Joshi, J.Y. Kim, Y.

Kim, A. Lyapin, D. McCormick, S. Molloy, J. Nelson, Y.J. Park, S.J. Park, C. Swinson,T. Tauchi, N. Terunuma, G.

White.LC-ABD meeting16th March 2010

SLAC, KNU, PAL, KEK, JAI-RHUL, UCL KEK, ATF

https://www.pp.rhul.ac.uk/twiki/bin/view/JAI/BeamPosition

1

BPM work

• ATF2

• Demonstrator system for ILC/CLIC final focus system

• Partially funded LCABD/EuCARD

• Large scale high-resolution system

• Diamond (NLS)

• Designed cavity for NLS

• Prototype fabrication stage

• CLIC

• Low Q cavity system

• ATF2 tests with ILC train as test system

2

BPM work

• ATF2

• Demonstrator system for ILC/CLIC final focus system

• Partially funded LCABD/EuCARD

• Large scale high-resolution system

• Diamond (NLS)

• Designed cavity for NLS

• Prototype fabrication stage

• CLIC

• Low Q cavity system

• ATF2 tests with ILC train as test system

3

ATF2 BPM layout

• S-band : 4 (dipole) +1 (ref)

• Variable attenuation and gain, unlocked local oscillator

• C-band : 33 (dipole) + 4 (ref)

• Locked LO system

• Attenuation : 20 db in all channels (2 BPMs no attenuation)

• 10 corrector calibrated

• 23 mover calibrated

1308.69

M M M M

M

M

M

M M M M M M M M M M M M M MM

REF

3FF

M M M M M M

MFB

1FF

MFB

2FF

MW

4X

nBPM

3 2 1R

Cn

IPB

PM

2 1R

CIP

MW

3X

ICT1

X

M M

MR

EF1

X

LW2X

MW

2X

LW1X

MW

1X M M M M Ms

Ms

Ms M M M MsM

REF2FF

MR

EF1FF

MS-2FF

M1-IP

(M2-IP)

M-PIP

MW

1IP

MS-PIP M

BS1-IP

ICT-

DU

MP

M-D

UM

P

MS-

1FF

160.36°

QD

10B

FF

QF5

BFF

BH

3X(Z

X3X

)

QF7

X

ZH3X

QD

8XZV

6X

KE

X2

QF9

XZH

4X

ZV7X

QK

1XQ

D10

X

ZH5X

QF1

1X

ZV8X

QK

2XQ

D12

X

ZH6X

QF1

3X

QD

14X

ZH7X

QF1

5X

ZV9X

QK

3XQ

D16

X

ZH8X

QF1

7X

QK

4X

ZV10

XQ

D18

X

ZH9X

QF1

9X

ZV11

X

QD

20X

ZH10

X

QF2

1X

ZV1F

F

QM

16FF

QM

15FF

QM

14FF

QM

13FF

QM

12FF

QM

11FF

QD

10A

FF

QF9

BFF

SF6

FF

QF9

AFF

QD

8FF

QF7

FF

B5F

F

QD

6FF

SF5

FF

QF5

AFF

QD

4BFF

SD

4FF

QD

4AFF

B2F

F

B1F

F

QF3

FF

QD

2BFF

QD

2A

SF1

FF

QF1

FF

SD

0FF

QD

0FF

IP

BD

UM

P

ZH1F

F

QD

10B

FF

QF5

BFF

BH

3X(Z

X3X

)

QF7

X

ZH3X

QD

8XZV

6X

KE

X2

QF9

XZH

4X

ZV7X

QK

1XQ

D10

X

ZH5X

QF1

1X

ZV8X

QK

2XQ

D12

X

ZH6X

QF1

3X

QD

14X

ZH7X

QF1

5X

ZV9X

QK

3XQ

D16

X

ZH8X

QF1

7X

QK

4X

ZV10

XQ

D18

X

ZH9X

QF1

9X

ZV11

X

QD

20X

ZH10

X

QF2

1X

ZV1F

F

QM

16FF

QM

15FF

QM

14FF

QM

13FF

QM

12FF

QM

11FF

QD

10A

FF

QF9

BFF

SF6

FF

QF9

AFF

QD

8FF

QF7

FF

B5F

F

QD

6FF

SF5

FF

QF5

AFF

QD

4BFF

SD

4FF

QD

4AFF

B2F

F

B1F

F

QF3

FF

QD

2BFF

QD

2AFF

SF1

FF

QF1

FF

SD

0FF

QD

0FF

IP

BD

UM

P

ZH1F

F

1308.69

M M M M

M

M

M

M M M M M M M M M M M M M MM

REF

3FF

M M M M M M

MFB

1FF

MFB

2FF

MW

4X

nBPM

3 2 1R

Cn

IPB

PM

2 1R

CIP

MW

3X

ICT1

X

M M

MR

EF1

X

LW2X

MW

2X

LW1X

MW

1X M M M M Ms

Ms

Ms M M M Ms

Ms M

sMR

EF2FF

MR

EF1FF

MS-2FF

M1-IP

(M2-IP)

M-PIP

MW

1IP

MS-PIP M

BS1-IP

ICT-

DU

MP

M-D

UM

P

MS-

1FF

160.36°

QD10X

QD11X

QD12XQD16X

QD17X

QD18X

QD19X

MREF1XQD20XQD21X

MREF3FFMREF2FFMREF1FFQM16FF

QM15FF

QM14FF

QM13FF

QM12FF

QM11FF

QM10(AB)FF

QM9(AB)FF

QD8FF

QF7FF

QD6FF

QF5(AB)FF

QD4(AB)FF

QF3FF

QD2(AB)FFSF1FFSF1FF

QF1FF

QD0FF

M-PIP

C-Band BPMsS-Band BPMs

CorrectorMover MFB2FFM-PIP

4

ATF2 BPM layout

1308.69

M M M M

M

M

M

M M M M M M M M M M M M M MM

REF

3FF

M M M M M M

MFB

1FF

MFB

2FF

MW

4X

nBPM

3 2 1R

Cn

IPB

PM

2 1R

CIP

MW

3X

ICT1

X

M M

MR

EF1

X

LW2X

MW

2X

LW1X

MW

1X M M M M Ms

Ms

Ms M M M MsM

REF2FF

MR

EF1FF

MS-2FF

M1-IP

(M2-IP)

M-PIP

MW

1IP

MS-PIP M

BS1-IP

ICT-

DU

MP

M-D

UM

P

MS-

1FF

160.36°

QD

10B

FF

QF5

BFF

BH

3X(Z

X3X

)

QF7

X

ZH3X

QD

8XZV

6X

KE

X2

QF9

XZH

4X

ZV7X

QK

1XQ

D10

X

ZH5X

QF1

1X

ZV8X

QK

2XQ

D12

X

ZH6X

QF1

3X

QD

14X

ZH7X

QF1

5X

ZV9X

QK

3XQ

D16

X

ZH8X

QF1

7X

QK

4X

ZV10

XQ

D18

X

ZH9X

QF1

9X

ZV11

X

QD

20X

ZH10

X

QF2

1X

ZV1F

F

QM

16FF

QM

15FF

QM

14FF

QM

13FF

QM

12FF

QM

11FF

QD

10A

FF

QF9

BFF

SF6

FF

QF9

AFF

QD

8FF

QF7

FF

B5F

F

QD

6FF

SF5

FF

QF5

AFF

QD

4BFF

SD

4FF

QD

4AFF

B2F

F

B1F

F

QF3

FF

QD

2BFF

QD

2A

SF1

FF

QF1

FF

SD

0FF

QD

0FF

IP

BD

UM

P

ZH1F

F

QD

10B

FF

QF5

BFF

BH

3X(Z

X3X

)

QF7

X

ZH3X

QD

8XZV

6X

KE

X2

QF9

XZH

4X

ZV7X

QK

1XQ

D10

X

ZH5X

QF1

1X

ZV8X

QK

2XQ

D12

X

ZH6X

QF1

3X

QD

14X

ZH7X

QF1

5X

ZV9X

QK

3XQ

D16

X

ZH8X

QF1

7X

QK

4X

ZV10

XQ

D18

X

ZH9X

QF1

9X

ZV11

X

QD

20X

ZH10

X

QF2

1X

ZV1F

F

QM

16FF

QM

15FF

QM

14FF

QM

13FF

QM

12FF

QM

11FF

QD

10A

FF

QF9

BFF

SF6

FF

QF9

AFF

QD

8FF

QF7

FF

B5F

F

QD

6FF

SF5

FF

QF5

AFF

QD

4BFF

SD

4FF

QD

4AFF

B2F

F

B1F

F

QF3

FF

QD

2BFF

QD

2AFF

SF1

FF

QF1

FF

SD

0FF

QD

0FF

IP

BD

UM

P

ZH1F

F

1308.69

M M M M

M

M

M

M M M M M M M M M M M M M MM

REF

3FF

M M M M M M

MFB

1FF

MFB

2FF

MW

4X

nBPM

3 2 1R

Cn

IPB

PM

2 1R

CIP

MW

3X

ICT1

X

M M

MR

EF1

X

LW2X

MW

2X

LW1X

MW

1X M M M M Ms

Ms

Ms M M M Ms

Ms M

sMR

EF2FF

MR

EF1FF

MS-2FF

M1-IP

(M2-IP)

M-PIP

MW

1IP

MS-PIP M

BS1-IP

ICT-

DU

MP

M-D

UM

P

MS-

1FF

160.36°

QD10X

QD11X

QD12XQD16X

QD17X

QD18X

QD19X

MREF1XQD20XQD21X

MREF3FFMREF2FFMREF1FFQM16FF

QM15FF

QM14FF

QM13FF

QM12FF

QM11FF

QM10(AB)FF

QM9(AB)FF

QD8FF

QF7FF

QD6FF

QF5(AB)FF

QD4(AB)FF

QF3FF

QD2(AB)FFSF1FFSF1FF

QF1FF

QD0FF

M-PIP

C-Band BPMsS-Band BPMs

5

ATF2 : System status

• C-band (6.5 GHz dipole mode)

• Good phase stability

• Amplitude stability ~few %

• Resolution order 1 micrometre

• S-band system (2.8 GHz dipole mode)

• IQ rotation (phase) instability

• Not present in calibration tone ~48 hours

• Becomes bistable with DR-RF ramp (can we try to avoid using DR-RF ramp for dispersion)

6

ATF2 introduction

• Work from December 2009 ATF2 operation

• Resolution studies

• All BPMs 20 dB attenuators (apart from ...)

• MFB2FF and MQM16FF full resolution (no attenuators)

• Chosen because magnets nominally off, can centre beam in BPM (both x and y) without disturbing optics

• Full system analysis (one file 1000 pulses all BPMs)

• Orbit reconstruction

• X-Y coupling

• QM16FF and MFB2FF resolution7

Reference orbit

• Cut on reference amplitude and QD10Xx position

• Bad extracts

• Low charge

8

Jitter in cavity BPMs

• Subtract reference orbit

• S-Band BPMs clearly have some problem

• Clear jitter dependence on beta-function

• Typically y jitter less 50 μm

9

X-Y correlation/coupling

• X-Y correlation for each BPM

• Scales suppressed but appears too large to be mechanical roll

• X-Y Coupling

• Need to remove to compute resolution

• S-band bistable although beam appears stable

QD10X

M-PIP

10

X-Y coupling subtracted

• Top plots are gradient and offset for the X-Y correlation can be large (-0.8)

• Lowest RMS vertical position jitter 0.61

• Need to perform full MIA/SVD style analysis

11

FB2 & QM16 calibration

• Centre BPM on beam, don’t have to worry about quad centre

• Range ±150 μm

• Quality of calibration is excellent

• Perfect for studies of BPM sensitivity

12

Towards high resolution

• Relationship between BPM EM centre and magnet

• Determine signal levels for normal quadrupoles well centred on beam (BBA)

• Can system tolerate this?

• Need to understand BBA offsets compared with high resolution dynamic range

• Require

• Might always be difficult horizontally as beam jumps out of un-saturated dynamic range

• Vertically probably o.k, what about the sextupoles? Large BBA offset

• SF6FF {x,y} = {2750, 604}

• SF5FF {x,y} = {2325, -205}

13

Towards high stability

• Need to inject calibration tone all the time

• Presently signal level too low

• Decision to inject all pulses with calibration tone

• Mix latter part of waveform with calibration tone frequency

• Extract scaling per pulse

• Apply to amplitude/phase for each digitized waveform

• Complex code upgrade will be run parallel to existing system

• Allows maximum time to test and debug (freeze existing operational version)

14

BPM system performance

• Kick beam using correctors

• ZH4X

• ZH6X

• Compare

• Optics model (R matrices)

• Orbit response with BPM measurements normalised by kick strength

Strip-lines C-band S-band

Y. Renier

15

BPM work

• ATF2

• Demonstrator system for ILC/CLIC final focus system

• Partially funded LCABD/EuCARD

• Large scale high resolution system

• Diamond (NLS)

• Designed cavity for NLS

• Prototype fabrication state

• CLIC

• Low Q cavity system

• ATF2 tests with ILC train as test system

16

Diamond/NLS BPM

• Started from ATF2 design

• Improved splitting between X and Y dipole modes

• Fully rounded edges for easy machining

• Cross compared CST-MWS, Gdfdl, HFSS etc codes

• Started with SLAC ACD EM codes

17

BPM work

• ATF2

• Demonstrator system for ILC/CLIC final focus system

• Partially funded LCABD/EuCARD

• Large scale high resolution system

• Diamond (NLS)

• Designed cavity for NLS

• Prototype fabrication state

• CLIC

• Low Q cavity system

• ATF2 tests with ILC train as test system

18

CLIC Main beam BPM

• Start from either low Q design

• CLIC design

• Requirement ~5 k MB BPMs

• Bunch separation, 0.5 ns

• Macropulse length 156 ns

• Require beam position information

• 10 ns (c.f 300 ns ATF2)

• Require low Q cavity design

• Ph.D project work of N. Joshi (DITANET)

19

ATF Multi train mode

• Preparation for new extraction scheme of ATF2 and analogue of CLIC BPMs

• Cavity decay time ~ 300 ns

• Change digital filter parameters

• Clear amplitude and phase changes

• Possible to extract position

151 ns bunch separation

20

Summary

• ATF2 CBPMs

• Large system working reasonably well

• Most of the system used routinely for model verification, dispersion measurement and beam based alignment

• Diamond CBPM (UCL-RG/JAI/Diamond)

• Design work finished

• Fabrication started

• CLIC main beam CBPM (funded CERN/JAI/DITANET)

• Design work started

• Some tests possible at ATF221