Status of CLIC BPM design and tests

07/11/2012 Lars Søby 1

• Design status for DB and MB

• Tests in CLEX

• Status of BPMs for test modules

• Outlook

CLIC Module Working Group

On behalf of: Alfonso Morell, Andrei Lunin, Alexei Luapin, Stewart Bogeert, Thibaut LefevreFrancis Cullinan, Sebastien Vilalte, Manfred Wendt, Jack Towler

07/11/2012 Lars Søby 2

BPM

CLIC Module Working Group

T1 module

•Resonant cavity beam position monitor prototype for CLIC main beam

•Low quality factor to provide multiple position measurements within a single train•Made from four stainless steel parts successfully

brazed together in April•RF characterization before and after brazing:

Cavity Position Reference

Resonant frequency/GHz 15.012 14.997

Loaded quality factor 198 150

Temperature stability of both cavities measuredCavity Temperature stability/kHz/oC

Position -359

Reference -308

Difference 51

07/11/2012 Lars Søby 3

Main beam BPM

CLIC Module Working Group

•Pick-up to be installed at the end of the CTF3 probe beam line in January 2013.•Horizontal and vertical mover stages for sensitivity measurement and calibration•OTR screen to ensure good beam transmission•Schottky diode detectors for initial measurements•Electronics designed for beam test of single BPM

07/11/2012 Lars Søby 4

MB BPM beam tests

CLIC Module Working Group

07/11/2012 Lars Søby 5

Main beam BPM

Design of acquisition electronics with commercial ADC is ongoing and will be installed in CLEX in a second test phase.

After evaluation of beam tests with one BPM and optimization of the designs, 3 BPMs will be installed in CLEX or ATF2 to measure the achievable resolution <50nm somewhere in 2014.

http://ibic12.kek.jp/prepress/papers/mopa18.pdf

CLIC Module Working Group

07/11/2012 Lars Søby 6

Drive beam BPM Compact model, fits into the quadrupole

vacuum chamber. Length L chosen for transfer function to

have zeros at 12 GHz (bunch cancellation in the middle of the train).

SiC damping ring added to absorb trapped modes at 12 GHz and above.

CLIC Module Working Group

Working around 20MHz

Frequency responsenot as expected

Incident

Reflected

7

450 Strip line BPM: Rough approximation of the original

07/11/2012 Lars Søby CLIC Module Working Group

Slide from M. Wendt Due to the fact that the transverse dimensions are comparable to the longitudinal ones, fields are not strictly TEM.

07/11/2012 Lars Søby CLIC Module Working Group 8

100 Stripline BPM:

Slide from M. Wendt

07/11/2012 Lars Søby CLIC Module Working Group 9

100 Small Strip line BPM:

Slide from M. Wendt

07/11/2012 Lars Søby 10CLIC Module Working Group

Diplexer 35MHz, 2nd order

T-bridge filter 20MHz, 1st order

T-bridge filter 4MHz, 1st order

ADCGSE to Diff

Digital attenuator

BPM

LAPP electronics

Signal from present 45 deg. design

450 Strip line BPM:

http://ibic12.kek.jp/prepress/papers/mopa16.pdf

07/11/2012 Lars Søby 11

Drive beam BPM beam tests

Girder 8

CLIC Module Working Group

8 channels, Fs=96Msps (CTF3 clock).

Lapp electronics to be used in this beam test.

07/11/2012 Lars Søby 12

Status of BPMs for Lab. modules

DB strip line Mock-up

• 4 DB Strip line Mock-ups manufactured for the two TM0 lab-modules. • 4 DB BPS manufactured by IFIC are at CERN for the TM1, TM4 lab modules.• 1 TM1 MB cavity BPM + vacuum chamber Mock-up has been manufactured. • TM4 MB BPM mock-up design not started yet!

BPS

MB Cavity BPM Mock-up

CLIC Module Working Group

TM0

TM1, 4

TM1

07/11/2012 Lars Søby 13

Tests in CLEX

4 DB Stripline mock-ups delivered

4 DB BPS delivered + 1 MB TM1 Vacuum assembly

Status of BPMs for modules

To be decided by BI before Christmas!

TM4?

CLIC Module Working Group

14

• DB BPM– The DB strip line BPM works well as an RF PU, but

does not suppress the 12GHz signals as foreseen in the 450 design, and have spurious resonances below 12 GHz.

– Signals from a 100 strip line BPM in a 11 mm diameter beam pipe demonstrate the concept.

– Beam tests will go ahead in CLEX for completeness, using external filtering.

– New designs will have to be evaluated such as, buttons, coaxial BPM…

Summary and outlook

07/11/2012 Lars Søby CLIC Module Working Group

15

• MB BPM– The MB cavity BPM has been thoroughly evaluated in

laboratory and looks promising. – Beam tests will be made in Califes beginning 2013.– After optimization of the design resolution

measurements tests will be done in either CLEX or ATF3.• Test modules– For lab modules a design of a TM4 MB BPM + chamber

must be started.– For the CLEX TMO nor yet clear for BI what to install as

DB BPM. Decision before Christmas.

Summary and outlook

07/11/2012 Lars Søby CLIC Module Working Group