# Minutes of 81st FFIR/BDSIM and 4th ILC-Asia WG4 meeting on 10/20/2004

The 4th meeting was held on Oct.20 10:00 am at rm.425 bldg no.3.
The meeting memo was wriiten by Kaoru Yokoya (KEK).

(1) Synchrotron radiation profile (Kuroda)
Presented a simple analytic formula to estimate the region
at QD showered by synchrotron radiation from upstream.
In the next meeting
* Tauchi will draw this result on his plot with phi=3.2mrad
* Kuroda will compare the formula with a simulation from
the collimator (The result can be different due to
the nonlinearity of the orbit)
(2) ATF2
* Kuroda presented the optics
(transparencies, pdf, 6 pages, 183KB)
* 3 optics with similar beam size (sigmax*=3.5um, sigmay*=36nm)
* computed the vibration tolerance for given emittance increase,
assuming the position can be corrected by feedback.
* computed the alignment tolerance under the correction
center-of-mass orbit + QD z-mover + SX x-y mover
+ dispersion correction.
Showed severe results for magnet roll (<0.1mrad)
* Discussion
* <0.1mrad roll is feasible. Sugawara will report the floor
motion at ATF in the next meeting.
* Alignment tolerance under center-of-mass orbit correction
is also needed
* Kuroda was asigned for the presentation of ATF2 at the
ILC workshop. Should mention about
(a) Comparison of real LC and ATF2 optics. What is the
effect of large emittance at ATF2.
(b) See if the hardware tolerances be considerably
different from real LC
(c) What is required on the stability of ATF beam
(d) What can be expected from ATF2 if extraction from ATF
at 300ns interval is possible
* Tauchi will report on the relation between ATF2 and
nanoBPM in the next meeting.
* Tauchi will show the layout of ATF2 in the next meeting.
Must be extended to GLCTA direction.
(3) Report of ILC US Workshop (Kumada)
Email from Kumada was presented.
(4) Workshop Program
* Sanuki presented the present draft
* Tauchi's talk on crossing angle and Kuroda's on ATF2
should be included
* 5 min presentation from individual labs are planned
on the 1st dat (1.5 hours). Is this needed?
* Other suggested presentation from Japan(Asia)
(a) Impact of photon-photon collision for the 2nd IP (Takahashi,
Hiroshima.U)
(b) background simulation (program) (Sanuki)
(c) final doublet technology (conventional, large bore and compact super,
permanent) (Iwashita, Kyoto.U)

### The next meeting will be on 27 October, 2004,10:00 - at 3 gokan, 425 .