Abstracts Brochure - CERN

THPLS078
THPLS079
THPLS080
THPLS081
29-Jun-06 16:00 - 18:00 THPLS — Poster Session
Tests of a New Bunch Cleaning Technique for the Advanced Light Source
The Advanced Light Source at the Lawrence
F. Sannibale, W. Barry, M.J. Chin (LBNL)
Berkeley National Laboratory is a third generation
synchrotron light source operating at
1.9 GeV and optimized for the production of soft x-rays. The machine usually operates with 400 mA of stored electrons
equally distributed among 276 contiguous buckets over the total of 328 available. The main reason for having this gap
is for allowing users to perform experiments where a long relaxation time for their sample is required. For such users,
a higher current bunch the "camshaft" is placed in the middle of the gap. Due to imperfect injection and to particle
diffusion from different bunches, the "empty" buckets present a level of purity of the order of 0.1% respect to the
camshaft current. This situation represent a signficant limitation for some users. In order to improve this situation,
we are testing a bunch cleaning technique that allows for the cleaning the gap to much better purity levels without
affecting either the camshaft or the other 276 bunches. In this paper we report on the results obtained so far.
Bunch Diffusion Measuments at the Adavanced Light Source
The Advanced Light Source (ALS) at the
F. Sannibale, W.E. Byrne, J. Guo (LBNL) A.S. Tremsin (UCB) Lawrence Berkeley National Laboratory is a
third generation synchrotron light source operating
at 1.9 GeV and optimized for the production of soft x-rays. Twice per years a special user operation shift of 2
weeks, is done dedicated to experiments where a long relaxation time for the samples is required. During these shifts,
the storage ring is injected with a two opposite bunches pattern with about 30 mA of stored current per bunch. Most
of the experiments require that all the other 326 remaining buckets must be clean from particles at a level of purity of
better than 0.01% of the total stored current. For this reason after the injection, we use a special procedure that cleans
the "empty" buckets to the required purity level. Particle diffusion from the main bunches must be avoided otherwise
the purity level will get progressively worst and an additional cleaning could be required after some time. In this
paper we present the measurements we did for the characterization of particle diffusion in the present ALS lattice.
Progress on Diagnostics Upgrades for ALS Top-off Mode
T. Scarvie, W. Barry, F. Sannibale (LBNL)
In preparation for top-off mode at the Advanced
Light Source, some old diagnostics
systems are being refurbished and several
new ones created. This paper catalogs the progress made on these top-off related upgrades. In particular, results
from our first booster-to-storage-ring transfer line synchrotron radiation monitor are shown, and progress on
the future storage ring bunch-by-bunch current monitor is presented.
Operational Experience with the Undulator Based Fs-slicing Source at the ALS
To improve the flux and brightness of the fs-
C. Steier, D. Robin, W. Wan, W. Wittmer, A. Zholents (LBNL) slicing source at the ALS, an upgrade project
has been completed. The new beamline uses
an in-vacuum undulator as a radiator, a high repetition rate fs laser and other upgrades to provide several orders
of magnitude higher flux than the original bend magnet beamline. In order to separate the fs-slices of the electron
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