Agenda and Summary:
1) Zero Degree Extraction Using an Electrostatic Separator -- Lew Keller
2) Beam dump for ILC -- Dieter Walz
FLUKA sumulations of water dump -- Heinz Vincke
Zero Degree Extraction Using an Electrostatic
Separator:
Lew studied using an electrostatic separator for a zero degree crossing
angle, attempting to solve the problems of the TESLA TDR design, namely the
losses on septum, losses on SR mask, large electric field needed for 1TeV. The
proposed solutions are: extract in horizontal plane, move the SR mask closer to
the IP, reduce the max field to 50 kV/cm at 1TeV (twice lower than in TESLA TDR).
The latter is possible due to advantageous optics where the defocusing quad QD2A
provides about 1.8mrad of additional kick. The design seems to represent
considerable improvement in comparison with TDR. The charged beam and
beamstrahlung losses appear tolerable for the "nominal" beam parameter set. Some
of the open issues are the very small (<1E-9 mbar) pressure required for
electrostatic separator, losses of scattered synchrotron radiation and radiative
bhabhas on the electrostatic plates, detailed design of extraction line and
possibility of diagnostics, much higher losses in high luminosity parameter
sets.
Beam dump for ILC :
Dieter presented the concept of a water dump for ILC. Heinz presented simulations of water dump with FLUKA. The notes are posted. The design work hasn't finished and the notes may be updated.
Andrei Seryi, 08/12/05