This meeting was devoted to ATF2 design discussion
Mauro Pivi: ATF2 optics & possibilities
to compress the bunch
- Mauro presented an updated ATF2 optics where Kuroda-san added a chicane
at the end of the extraction line, to separate the gammas from the laser
wire scanners from the main beam, and matched it to NLC-like FF. Mauro also
looked at the possibility to compress the bunch in the existing extraction
line optics, without an additional bunch compressor. The compression is
complicated by the large second order term T566. It appears that compression
of a factor of two or so may be possible, for the cost of increase of the
energy spread to approximately +-1%. This estimation was done using Gaussian
shape of the bunch, and in reality the profile is different, which can be
used as an advantage. Compression should be checked with real tracking.
Preservation of the beam emittance should be considered.
Marc Ross: IP BPM suggested by V.Vogel and
requirements to the IP
- Marc described the idea of the 1nm resolution IP BPM suggested
by V.Vogel. One of the requirements of this design is to have 6mm
diameter beam pipe near the IP, about 250mm long. Implications of this
should be evaluated
Andrei Seryi: Discussion of magnets
- Andrei considered reducing the length of the quadrupole from present
0.5m to 0.2m. This would allow to increase the pole-tip field, and be
more close to the existing magnets, and also provide more space for BPMs.
He also considered the aperture requirements if we were to assume the
most aggressive energy spread of +-1% square distribution (that would
correspond to compressed bunch). In this case the apertures for the most
critical magnets have to be at least 15mm.
Cherrill Spencer: Ideas for ATF2
- Cherrill presented existing designs of earlier built inexpensive
air-cooled magnets that can be used for part of the magnets of AFT2 (in
particular for QM series).
Marc Ross: Existing magnets for ATF2
- Marc described and showed photos of existing quadrupoles that can be
used for QM series of ATF2 magnets. This quads have 0.5inch bore
diameter and they are 6 inches long. The vacuum chamber going in and out
of these quads have to be reduced.