Notes from ESA meeting held March 13:
Agenda for meeting can be found at
http://www-project.slac.stanford.edu/ilc/testfac/ESA/meetings/agenda13mar2006.html
1. T-474
i) M. Slater reported on optimizing 3 parameters used in the DDC that processes data from
23MHz to dc: i) bandpass of low pass filter, ii) cutoff of filter and iii) trigger offset.
Mark finds a factor 2 improvement by increasing the bandpass from 3MHz to 7.5MHz. He
achieves 1.5-micron single bpm resolution, comparing X41-X42 on Run 121 for a single
corrector setting. The bandwidth optimization may be bpm-dependent, so will investigate
that.
ii) Mark has finished processing the January data.
ii) Mark and Yury will also look for analyzing drifts in relative bpm offsets for different
time scales.
iii) Yury reported that bpm 32 waveforms were bad during january run and information from that
bpm is not useful. Need BSY access (has been requested, but not scheduled) to investigate.
BPM31 data looks good but can't determine resolution. Combined jitter and resolution is
about 20-30 microns.
iv) Yury reported on crosstalk measurements. BPM41 clearly sees 2 peaks in Fourier transform
and there is significant x-y coupling, in part due to a large offset which can be corrected
with the alignment we will do. Yury wants to add isolators, which we've now located from
Steve Smith.
v) Doug reported that the Zygo laser was not sent to Notre Dame and will remain at SLAC.
2. 3BPM3-5
i) will bring to ESA this week
ii) Doug needs 2 single-width Camac stepper motor controllers for the x,y mover control on 3BPM4
3. T-480
i) the last 3 collimators are being shipped from the UK by March 14.
ii) Bruno, Matt Hayes and Ray met on 3/10. Sandwiches should be machined week of March 13.
2 sandwiches have significant differences and Bruno is documenting these.
4. T-FONT
i) some changes were made to the bpm spool piece design. Daresbury has drawings and is
starting soon on this. Christine is communicating with Alexander for this. She will travel
to the UK March 14 for 2 weeks.
ii) the BPM to be used will stay at SLAC, since it's radioactive. Visual inspection has been
done and it matches the drawings sent to Daresbury.
5. Bunch length diagnostics
i) Doug has ordered the last pieces needed. Some parts will arrive after he departs March 29
(back at SLAC April 24) for KEK. Sean will take care of final installation. He's at KEK
only for April 6-13.
ii) Doug has a 95GHz rf source for testing/calibrating the two 100GHz diodes we'll use. Joe
Frisch is working on a transimpedance amplifier to match the high impedance diodes to
the 50-ohm transmission cable.
6. DAQ
i) Doug is providing a circuit to condition the 119MHz for the SIS adc. It's ready to test.
ii) Work is needed for accommodating the extra 2 SIS modules for logging data to disk.
iii) current server barely keeps up with 4 SIS in system and data at 10Hz. Need to
install new fast server PC; should be ok.
iv) the SIS triggers don't currently have a DAQ veto implemented. Need to do this.
7. ESA misc. (Carsten)
i) will mount 4 earthquake frames on beamline this week
ii) spreader bar calculation is done for hoisting SPEAR girders
iii) water is off on beamline
iv) electrical safety walkthru on 3/13
v) other test beam experiments in may/june possible in ESA: ANITA? and T-469?
vi) grounding check of ESA was done -- 20 ohms to ground was found; will be fixed over next
3 months
vii) reminder that users need to inform Carsten of work being done in ESA
viii) BaBar down will start march 27, so want to complete ESA rigging by March 24
8. EMI (Gary Bower)
i) plan on 3 antennas covering range up to 2.5GHz. Need to buy high frequency antenna from
AH Systems. 2 lower frequency antennas can be borrowed from GLAST.
9. Beam optics
i) Frank is working on the ELEGANT simulations. Not getting expected results yet.
ii) Q30 range for quad emittance scans was fixed March 15.
iii) Mike to contact Rick Iverson about online model.
10. Chicane magnets
i) Ray met with Dieter Walz to discuss plans. He has obtained drawings with specs and
tolerances. Plan to machine off few mm on pole faces. No modifications to nose pieces,
used for field shaping, should be needed. Beam is small and well centered in magnets.
Next meeting March 20
There are minutes attached to this event.
Show them.
