Gilbert Guignard, 20 June 2003
CLIC meetings minutes, for 2002 and beginning of 2003.
Meeting of January 18, 2002
Michael Poehler
Status of the work on civil engineering and layout for
CLIC, which included a tentative layout of the central area with the injection
complexes, was given.
Meeting of February 15, 2002
Oliver Forstner
Title: Ion Post Acceleration with REX-ISOLDE
REX-ISOLDE is a post-accelerator for radioactive ions
from the ISOLDE facility. In REX-ISOLDE ions are captured in a Penning trap
(REXTRAP) and then transported to an EBIS (Electron Beam Ion Source). The
following LINAC accelerates the ions to 2.2 MeV/u final energy. In this talk,
an overview of REX-ISOLDE was given and the low-energy section (REXTRAP-
EBIS) was described in more detail.
Meeting of March 1, 2002
Williame Coosemans
Réseau de métrologie pour main and drive linac, simulations
influences des phénomènes de variation gravimétrique
Steve Hutchins
Alignment techniques based on lasers
Meeting of March 8, 2002
Daniel Schulte
Short view of simulation results related to the pre-alignment
strategy discussed in the preceding meeting on alignment techniques.
Nicolas Leros
Beam based correction by structure displacements.
Jan Prochnow
Study of the realization of the structure beam-position
monitors – BPMs.
Meeting of May 3, 2002
Mathias Brandin, Uppsala University
Preliminary exploration of the use of a high-frequency,
high-gradient two-beam accelerator based on CLIC as an X-ray Free Electron
Laser driver.
Meeting of May 17, 2002
Greg Penn, Scientific Associate from Berkeley University
The relationship between axial-symmetric beams with
coupled transverse motion, electron beams created in a magnetic field , and
highly elliptical beams have been discussed. Different definitions of emittance
used for coupled beams were compared for clarification. This has applications
to generating high quality elliptical beams, as in FNAL photo-injector flat
beam experiment, and to transforming a ribbon beam into a large round beam
in a reversible way.
Helmut Burkhardt
Simulation of muon background in GEANT4, covering the
muon-pair production in electro-magnetic showers by high energy photons.
Meeting of May 24, 2002
Ian Wilson
Review of the activities carried out in 2001 on the
CLIC study and the test facilities.
Meeting of May 31, 2002
R. Chebab, LAL, IN2P3-CNRS et Université Paris-Sud, Orsay
Title: A channeling experiment at CERN for a future
positron source (WA103).
The experiment WA103, which concerns a new kind of positron source using
channeling radiation of multi-GeV electrons in tungsten crystals to obtain
a large number of e+e- pairs, has been worked out on the X5 transfer line
of the SPS in 2000 and 2001. The incident electron energy was between 5 and
40 GeV, working mainly at 6 and 10 GeV. Crystal and amorphous targets of
different thicknesses has been used. The data gathered on this experiment
has been partly analyzed. Some results related to the momentum and angular
distributions of the emitted positrons, obtained after reconstruction of
the positron tracks in the main detector, the drift chamber, were presented.
A rapid status on the R&D activities, for this kind of source, was also
given.
T.Suwada, KEK, Japan
Title: Positron production experiment in Tungsten crystal
using 4 and 8 GeV channeling electrons at the KEKB injector linac.
Intense positron sources are widely investigated for
the next-generation linear colliders and B-factories. A new method utilizing
an axially oriented crystal as a positron-production target is one of the
bright schemes since it provides a powerful photon source through channeling
and coherent bremstrahlung processes when high-energy electrons penetrate
the target. A series of positron-production experiments with crystal tungstens
hit by 4 and 8 GeV single-bunch electron beams were carried out at the KEKB
8-GeV injector linac. Three tungsten crystals with different thicknesses
(2.2, 5.3 an 9.0 mm) and those combined with amorphous tungsten plates were
tested on a precise goniometer. The positron production yields were measured
with a magnetic spectrometer in the positron momentum range from 5 to 20
MeV/c. The angle of the crystal axis with respect to the electron beam direction
was controlled by measuring the relative intensities of the produced positrons
as a function of the rotational angle of the goniometer. The results showed
that the enhancements of the positron yield from crystal targets compared
to amorphous targets of the same thickness at 20 MeV/c were from 1.5 to 3.7
and from 1.8 to 5.1, depending on the target thickness for 4 and 8 GeV electrons,
respectively.
Meeting of June 21, 2002
Presentation by W.Wuensch, F.Zimmermann, P.Royer and
S.Redaelli of the most interesting topics from EPAC2002 Conference, with
an emphasis on the papers submitted there in connection with CLIC/CTF activities.
Meeting of June 28, 2002
Lars Groening, GSI, Darmstadt
Report on the Coherent Synchrotron Radiation Workshop,
which took place in Berlin at the beginning of February 2002.
Meeting of August 2, 2002
Thibaut Lefèvre
The laser-wire test experiment carried out on CTF2,
analysis of the results, investigations-observations and future plans.
Greg Penn, LBL, California
Simulations of gamma production and background for the
laser-wire of CTF2 to compare with the experiment, and numerical study on
the basic effects due to a laser-wire in a CLIC beam, production of degraded
e-, impact in a detector, effects of losses, next steps.
Meeting of October 4, 2002
R.Assmann and S.Redaelli
CLIC stabilization results and measurements on water
induced quadrupole vibrations.
F, Zimmermann
Quantum mechanics limitations on beam demagnification
and luminosity.
Meeting of October 10, 2002
Greg Loew, SLAC, Stanford, California
Title: Report from the International Linear Collider Technical Review Committee.
The Committee was set by ICFA in 2001 with the charge
to assess the four linear collider approaches, which are developed to meet
an energy of 500 GeV c.m. with a luminosity on the order of 1034
cm-2s-1, and their potential extendibility to higher
energies. The activities of the committee started about a year before and
reached at the time of the meeting the point where a final report summarizing
them has been put together. Greg Loew gave an overview of the assessments
that the report contains about the technology, performance and reliability
of each design, together with the R&D work that remains to be done.
Meeting of October 18, 2002
Frank Zimmermann
Design recipe for a compact final focus and a first
draft design for an FF test at CTF3.
Maxim Korostelev
Damping ring design status report.
Meeting of January 24, 2003
Maxim Korostelev
Advanced presentation of the talk, which was given then
in the Damping Ring Workshop at Daresbury (January 27-29) with the most recent
developments on the subject at the time.
Meeting of February 10, 2003
The usual CLIC meeting left the stage to an open ESGARD
information meeting (most of the day) which was in particular important for
the CLIC team members. Following a general presentation of the European Frame
Program 6 (FP6) and an introduction of the Integrated Activity concept, the
Network Activities (NA) and Joint Research Activities (JRA) planned to be
proposed for Accelerator R&D were presented to the community of interested
people. Were covered the net-working activities on e+e- linear accelerator
and collider, on the neutrino beams and on high-energy/high-intensity proton
beams, as well as the joint research activities on Superconducting Cavity
Technology, on Super-conducting RF Technology, on Photo-Injectors, on High
Intensity Proton Pulsed Injector, on High Field Magnets and on Accelerator
remote control/operation.
Meeting of February 28, 2003
Jean-Pierre Delahaye
Organization of the CLIC Study after the AC restructuring.