Mauro Pivi: ATF2 Optics - Kuroda & Okugi Design
- Mauro Pivi presented optics of the existing extraction line at ATF, and
also the suggested extraction line optics that could bring the beam to GLCTA
area designed by T.Okugi. Mauro converted them from SAD to MAD.
- M.Pivi and T.Okugi are also working on comparison of S.Kuroda's ATF2
final focus optics with MAD and SAD. The bandwidth calculated by SAD is
similar, though slightly smaller in Y, most probably because MAD does not
include certain aberrations when the bandwidth is computed (this is
known issue in MAD). Comparison of tracking with SAD and Turtle are ongoing.
Andrei Seryi: Comparison of Kuroda vs. scaled NLC Optics for ATF2
- A.Seryi has shown optics of existing extraction lines combined with
S.Kuroda's final focus and also with the final focus scaled from the NLC
optics. Tracking results show that bandwidth in both cases is larger than
ATF extracted beam energy spread. The latter version has wider bandwidth,
since it was optimized from the start together with the extraction line.
- Two more optics of (extraction + ff) will be produced: those with GLCTA
Comparison of optics would involve comparison of tolerances, tenability, and
possibility to scale to 1TeV.
Mark Woodley: Vertical Dispersion in the ATF Extraction Line
Mark Woodley reported about studies of vertical dispersion correction made
in 2000 in the ATF extraction line. In that case, vertical dispersion was
detected in the wire scanner area and corrected using vertical bump in the
dispersion area. Further modeling has shown that
correctors could not produce the observed amount of vertical dispersion,
unless a sextupole error is present in the bends. This was later confirmed,
that the bends indeed have sextupole component close to the limit of
This is described
in this report.
These sextupole components need to be taken into account when any correction
of the second order dispersion is considered in the ATF extraction line.
(Presently, there are two skew quads installed in the high dispersion
points, for vertical dispersion correction, and other four in the wire
Okugi-san commented about the GLCTA extraction line design, that this was
designed for bunch compressor, and correction of second order dispersion was
not considered. Also, this optics does not have instrumentation section, as
the existing extraction, and this needs to be added to the beamline before
the final focus.
Yuri Nosochkov: Extraction Line for 20mrad
Crossing Angle IR
Yuri Nosochkov presented nearly finalized design of the extraction line for
20-mrad x-ing angle. Tracking show no losses of disrupted beam. Further
tests need to include disrupted beam from collisions of non-ideal beams, and
beams with offsets. If there will be no losses detected in that case, the
apertures of the quads can be reduced. Manufacturability of these quads are
now being studied.
Clay Corvin: CF Considerations for Straw Man
- Clay Corvin presented draft layouts for ILC and described what
limitations, in terms of locations of the dumps, separations of the IR
halls, space needed for drive-in ramps, location and size of muon walls,
etc., have been considered during the NLC design. These lessons and
experience will be now applied to design of the ILC IR layouts.