1. T-480
i) will likely want to repeat some measurements in July run, but will have limited
manpower: S. Molloy + SLAC people
ii) analysis of Run 1 data needs better bpm calibration data; highest priority is for
a time window spanning the T-480 run periods May 5-7
2. T-474
i) Analysis of Run 1 data:
- T-474 analysis meeting held May 17; next meeting June 1
- need to determine optimal DDC parameters for each cavity (esp. for BPM3-5)
- algorithm for saturated pulses needs improvement
- need t0 determination for runs w/ internal clock
- perform calibrations using all calibration runs after above is done
- reprocessing of data after above is done
- initial focus on data after final alignment on May 5
- need to determine any alignment moves needed before july run
- notes on bpm problems during run 1:
- 41Q was bad and 11Q was dead throughout run
- 32X and 9X were dead for parts of run
- 41Y is 3MHz off frequency; large x-y coupling if large x offset; needs special
treatment; need to add isolator for July run
ii) Zygo laser for july run
- Mike H. and Zen had good success commissioning this during Run 1; laser and optics
were aligned and VME readout of data commissioned; 1/2-hour of data was taken and
logged. Good resolution and stability (~10nm?) was achieved in the test setup.
- system layout is done and can start to implement this
- will need 5 15-m fibers (1 for laser and 1 each for signals from 3 bpm retroreflectors +
1 spare) to be run in conduit from VME module to beamline
iii) electronics
- will use 2 spare SIS channels in ChA for energy bpm 24X,Q
- need to check if temperature monitoring for bpms has adequate resolution
- need to do more studies on external clocking with 119MHz; Doug and Yury will set up to
do some tests with a cw signal and the LO to do a tone test. Need to understand
issues of sensitivity to phase. Improved resolution wrt internal clocking is possible
though.
iv) magnets
- need to write a work order for Terry Tuck to work on refurbishing magnets
- plan to have a phone meeting with Dubna week of May 22; Bino and Alexei will be visiting
there that week.
3. Linac BPMs 3BPM3-5
i) for July run, record waveforms on fast scope; need to commission fast scope in ESA
and be able to communicate with it remotely
4. T-475
i) need BSY access for further improvements to shielding and to add ~3mm Pb pre-radiator
5. T-FONT
i) toroid for total flux measurement? may be able to commission toroid to measure
flux in range 5e5 - 5e8, overlapping with other toroids that read 1e8 - 1e11, and
compatible with low current toroid being set up for ANITA tests
ii) plan to reinstall 3PR3 just upstream of BPM module for flux profile measurement. Would
start up with existing Al-oxide screen with primary beam and then switch this to
a scintillator and middle for secondary beam. Need to recommission cableplant and
provide air to the air cyclinder for in/out control. Can also locate spill counter
near this to try to cross-calibrate with toroid and extend to lower fluxes than toroid
can provide.
iii) with above 2 methods for flux measurement, ESA setup is set up to quickly switch back
and forth between primary beam and secondary beam; another alternative for profile
measurement is to make a wire card for 3WS1 with a thick wire or ribbon foil (looking at
SEM signal is also a possibility), but this limits ability to switch back to primary beam
if we need to know spotsizes at 3WS1--for example for T-480 studies. Will need to work
with MFD if we want to do this and will want a ceramic card if we want to look at SEM
signals.
iv) need 4 1/2" heliax cables from ChA to 3C2 location; they should be TDRed to have same
length to 100ps. This for the bpm signals.
iv) The BPM module is being built; the carbon and lead are ordered. Ray has identified
support stands to be used and modified.
v) We need to submit the test beam proposal in the next week; this is needed for evaluation
by radiation physics.
6. Bunch length measurements for July
i) Doug indicated that plan to install a toroid spool piece previously associated with 3WS1,
minus the toroid, to have an exposed ceramic gap. Will install a pyroelectric detector
(they're much cheaper at $500ea compared to 200GHz diode estimated at $5K each). Will
provide alignment capability to look at different angles; rf emission is very forward.
May have a dc motor to change position, or may take access to do this manually.
7. DAQ
i) Zen has coped the Run 1 data to mstore.
NEXT MEETING: MAY 22
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