Minutes of the CLIC Meeting - 15 September 2006
Agenda:
|
Highlights of LINAC'06 Conference
Summary
of Experimental Results for the
Cu HDS60 Structure
|
Speakers:
|
Steffen Döbert, Alberto
Rodriguez |
Abstract
The first HDS
structure test has been concluded. The main experimental results of
this test will be presented including conditioning history, breakdown
rate experiments and pulse length and repetition rate dependences.
Steffen
presented a summary of the
LINAC'06
conference in Knoxville, TN, USA. Four papers were presented from our
group with a talk about CTF3 by Günther. It was felt that a
general talk about CLIC was missing.
About 2/3 of the topics were related to heavy ions and protons. In
particular, the main facilities presented were:
- FAIR (GSI):
facility is approved, it's in the design and development phase, still
looking for collaborations
- SNS: has been commissioned with beam and is working well at low
power, the power will have to be increased in the future
- ISAC (Triumph, Vancouver): SC booster for radioactive particles
- CERN high intensity proton linac (Linac4, SPL).
For electrons, many contributions
were about FEL's and ERL's (energy recovery linacs). Desy's XFEL
project and FLASH (TTF as a user facility) were presented. Daresbury is
very active for a ERL prototype, that is close to approval.
SPRING8 with the NC C-band linac fed by a thermionic gun obtained a
gradient of 35 MV/m and reported the first lasing. SLAC's LCLS
commissioning is foreseen for next January.
A lot of work is ongoing for RF guns, especially aimed at a good vacuum
for the productin of polarized electrons. Many projects dealt with
military applications based on high power FELs.
ILC had not too many contributions and only one oral presentation. The
posters were mainly basic SC RF R&D. Japan has a program to reach
the gradient of 35MV/m for the standard cavities with 95% yield. 120
cavities are planned to be built in the next 3-4 years. In parallel,
other higher gradient designs are pursued. Good single cell results
have been obtained but a large spread is still present.
Other topics covered were laser and plasma acceleration where some
progress is visible. Laser accelerations can produce GeV e- beam with
reasonable beam properties. One talk presented the outcome of the
report
of the future of elementary particle physics of the EPP2010
committee. This ranked 'R&D needed to make a the US competitive in
the science and technology needed for the the International Linear
Collider' second after LHC exploitation.
Alberto
showed the results of the latest tests of the Cu HDS60, that was
both forward and backwards mounted to compare the different behaviour.
He showed the results for the backwards case. The ~400 hours of beam
time for the tests were accumulated during 20 days. This indicates that
about a month is needed for tests of a structure, including mounting
and conditioning time. Increasing the repetition rate of the beam will
certainly reduce the time for the tests.
Breakdown rate experiment results were shown for the two different
aquisition systems for different pulse length. The rates differ
slightly, probably due to speed limitations of the old system. For the
first time, breakdown rates as low as 10-5 were directly
measured.
A pulse length dependance study shows that the maximum power could be
consistent with a t1/3 dependance.
The results of a repetition rate dependance study still need further
analysis and verification.
Finally, Alberto presented photos of the structure after the tests that
showed that the first cell on each side is different in colour. Also
signs of some activity inside the damping slots all along the structure
were visible.
copy of Alberto's
transparencies (PowerPoint
format)
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Frank
Tecker - Last updated 15-09-2006