Status of CLIC BPM design and tests
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Transcript of Status of CLIC BPM design and tests
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
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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
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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
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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
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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
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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.
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100 Stripline BPM:
Slide from M. Wendt
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100 Small Strip line BPM:
Slide from M. Wendt
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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
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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.
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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
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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
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• 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
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• 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