FONT meeting notes of October 5 + 12 2007
Present:
Hamid, Tony, Ben, Colin, Robert (Oxford)
Alexander (DL)
Christine (Tunbridge Wells)
Phil (SLAC)
Javier (Valencia)
1. Hardware updates
-------------------
Ben has made good progress with the UART transmission programming.
He can empty RAMs and write ASCII or Matlab files.
He has set up a bench test system using one FB board to drive the other.
Colin will help with the beam trigger simulation.
Hamid has cabled up the Xilink Virtex5 development board and checked its
basic functionality. (Ben's UART code should also work with V5).
With Colin he has checked the new ADC noise and finds it meets the specs.
Hamid also tested the PROMs on the 2 recently-loaded FONT4 boards and
finds they work ok.
Colin reported that the new power supply is in.
Alexander has examined 3 amplifier types for the new BPM processor - see
file on www.
The RFMD and Macom devices are candidates for the input amplifier; the
Minicircuits device is needed for the synchronous detector reference signal.
All are quite fast and have decent bandwidth: 600 - 1800 MHz, and good gains.
The RF2360 looks good overall.
2. Preparations for ATF visits
------------------------------
Ben and Christina will go out to KEK on October 24th, arriving 25th.
They need to book the dormitory accommodation.
They have gathered the equipment needed.
Christina has prepared a work list for the BPM processor tests - ad hoc
modifications to the boards to be discussed with Colin.
**ACTION: CHRISTINA
Ben has a parasitic programme of FONT4 board readout tests.
Ben will put the DAQ code on the new PC. A travelling case has been identified
and needs to be ordered.
** ACTION: BEN
Colin noted the usefulness of examining the kicker-gap adjustment mechanism
in case we decide to improve the position readback. Ben will look into it.
** ACTION: BEN
We need to think about the December visit dates. Alexander and Colin will
think about the numbers of shifts needed.
** ACTION: COLIN, ALEXANDER
3. Simulation work
------------------
Tony reported on his updated beam-beam pair simulations - see file on www.
Of the gamma gamma -> e+e- events 71% are virtual/real, 23% virtual/virtual
and 6% real/real.
Not included in CAIN or GUINEAPIG are various polarisation effects and 2nd
order processes.
Tony has included Sokolov-Ternov polarisation terms for the Breit-Wheeler
process in CAIN. He finds a factor of two reduction in pairs below 10 MeV
and that the pairs are completely depolarised. Looking over the 7 machine
parameter sets for 500 GeV c.m. energy he finds 10-20% fewer pairs.
He is close to completing the implementation of the 2nd order processses.
There are many narrow resonances that need to be integrated over.
Colin noted the need to benchmark the calculations wherever possible.
Javier had presented the updated ILC intra-train FB simulations at the
recent ILC LET meeting. He confirmed with Glen the effect of the reduced
wakefield effects in the ILC cavities. He will discuss also with Daniel
next week at CERN. He will run multiple seeds to check the luminosity
distribution.
At the CLIC meeting next week Javier will present the non-linear collimation
scheme for CLIC, and Tony the beam-beam effects for CLIC, as well as
reporting on the FESA results.
4. FONT papers
--------------
Glenn had emailed from Hungary. He will draft a FONT4 paper for eventual
submission to NIM. Tony agreed to start drafting a paper on the FESA simulations
and experimental results.
Next meeting:
-------------
Friday October 19: 08.00 SLAC / 16.00 UK
best wishes,
Phil
There are minutes attached to this event.
Show them.