| Paper |
Title |
Other Keywords |
Page |
| MOXMA02 |
Commisioning Experience of SNS
|
linac, target, injection, beam-transport |
6 |
| |
- M. A. Plum
ORNL, Oak Ridge, Tennessee
| |
The Spallation Neutron Source accelerator complex consists of a 2.5 MeV H- front-end injector system, a 186 MeV normal-conducting linear accelerator, a 1 GeV superconducting linear accelerator, an accumulator ring and associated beam transport lines. The linac was commissioned in five discrete runs, starting in 2002 and completed in 2005. The accumulator ring and associated beam transport lines were commissioned in two runs in February and April 2006. With the completed commissioning of the SNS accelerator, the facility has begun initial low-power operations. In the course of beam commissioning, most beam performance parameters and beam intensity goals have been achieved at low duty factor. A number of beam dynamics measurements have been performed, including emittance evolution, transverse coupling in the ring, beam instability thresholds, and beam distributions on the target. The commissioning results, achieved beam performance and initial operating experience of the SNS linac will be presented.
|
|
|
Slides
|
|
|
| TUPMA034 |
Operation Experience of Top-up injection at Taiwan Light Source
|
injection, storage-ring, photon, insertion-device |
151 |
| |
- G.-H. Luo, H.-P. Chang, C.-T. Chen, J. Chen, J.-R. Chen, C.-C. Kuo, K. S. Liang, Y.-C. Liu, R. J. Sheu, D.-J. Wang
NSRRC, Hsinchu
| |
The storage ring of Taiwan Light Source (TLS) has one Superconducting (SC) cavity, one SC wavelength shifter, and two SC wigglers installed during last two years. The operation mode was also upgraded to have the capability of top-up injection. Top-up is an operation mode in which the beam current is maintained above certain level by frequent injections in the storage ring. The current stability maintains in the range of 10-3 for long period of operation. It provides constant thermal loading on all components in the storage ring and the optics components of beamlines, as well as constant signal to the beam position monitor. The top-up injection is a routine operation mode during user shifts at TLS. Statistics, operation experience and future expansion will be discussed in this paper.
|
|
|
|
| TUPMA099 |
Adiabatic Damping of the Bunch-length in the Induction Synchrotron
|
acceleration, synchrotron, damping, induction |
244 |
| |
- T. S. Dixit
GUAS/AS, Ibaraki
- Y. Shimosaki, K. Takayama
KEK, Ibaraki
| |
A fact that a bunch-length shrinks with the barrier-bucket acceleration in the induction synchrotron [1], where a single proton-bunch injected from the 500 MeV Booster was accelerated to 6 GeV in the KEK-PS, has been observed [2]. This has been supposed to be simply explained by a term of adiabatic damping. A technique to analytically deal with such an adiabatic dumping in a case of RF bucket acceleration is well-known; a WKB solution is employed for the small amplitude synchrotron oscillation. However, the simple WKB approach is not available for the present barrier-bucket acceleration, because the longitudinal motion always depends on the oscillation amplitude. A novel technique capable of quantitatively predicting the adiabatic phenomenon in the barrier-bucket acceleration has been newly developed. It turns out that the experimental result, numerical simulation, and analytic prediction have been in good agreement with each other. Theoretical approaches tell us that a bunch-length in the barrier-bucket acceleration never continues to shrink but achieves a constant value corresponding to the time duration between barrier voltages.
[1] K. Takayama and J. Kishiro, Nucl. Inst. Meth. A451/1, 304-317 (2000)[2] K. Takayama et al., “Experimental Demonstration of the Induction Synchrotron”, published soon.
|
|
|
|
| TUPMA102 |
Installation and Radiation Maintanance Scenario for J-PARC 50 GeV Synchrotron
|
vacuum, extraction, septum, synchrotron |
247 |
| |
- M. Yoshioka, T. Fujino, Y. Hori, K. Ishii, H. Kobayashi, T. Kubo, H. Matsumoto, H. Oki, T. Oogoe, Y. Saito, Y. Sato, M. Shimamoto, M. J. Shirakata, Y. Takeuchi, M. Uota, Y. Watanabe
KEK, Ibaraki
- M. HOSOKAWA
THK CO., LTD, Hitachinaka
- Y. Kuniyasu
MELCO SC, Tsukuba
| |
Installation and assembling of accelerator components for J-PARC 50 GeV Synchrotron are now underway. Off-beam commissioning will be carried out between December 2007 and April 2008, and the full commissioning of J-PARC accelerator complex, which is consisted of an injector linac, a 3 GeV rapid cycling synchrotron and the 50 GeV Synchrotron, will be started from May 2008. This paper describes the status, schedule and method of installation and assembling of accelerator components. Radiation maintenance scenario will be also described.
|
|
|
|
| TUPMA105 |
Transverse Matching of the SNS Linac Based on Profile Measurements
|
linac, emittance, quadrupole, proton |
250 |
| |
- D.-O. Jeon, P. Chu
ORNL, Oak Ridge, Tennessee
| |
For a high intensity linac such as the SNS linac, it matters to match to minimize the beam mismatch and potential beam loss. It was observed that matching was improved through the matching technique based on the beam profile measurements from wirescanners.
*SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U. S. Department of Energy.
|
|
|
|
| TUPMA108 |
Benchmarking of Multiparticle Phase Scan and Acceptance Scan Techniques for the SNS DTL
|
linac, simulation, target, space-charge |
253 |
| |
- D.-O. Jeon
ORNL, Oak Ridge, Tennessee
| |
For a high intensity linac such as SNS Drift Tube Linac, it matters to accurately determine the rf set-point of the tank rf field to minimize beam mismatch and potential beam loss. Two techniques were benchmarked which are multiparticle phase scan and acceptance scan techniques. Excellent agreement was obtained between the set-points obtained from the two techniques. The analysis of both techniques are based on multiparticle tracking using the Parmila code.
*SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U. S. Department of Energy.
|
|
|
|
| WEC3MA01 |
Experimental Verification of Halo Formation Mechanism of the SNS Front End
|
optics, emittance, linac, simulation |
333 |
| |
- D.-O. Jeon
ORNL, Oak Ridge, Tennessee
| |
A new halo formation mechanism predicted by the simulation study was confirmed through a series of emittance measurement during the SNS Linac commissioning. The rms emittance and beam tail were greatly suppressed by the cure of transverse optics change. Detailed analisys and comparison of emittance measurement and simulation are presented here.
*SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U. S. Department of Energy.
|
|
|
|
Slides
|
|
|
| THPMA078 |
Wideband Current Transformers for the Surveillance of the Beam Extraction Kicker System of the Large Hadron Collider
|
extraction, kicker, collider, shielding |
746 |
| |
- C. Defrance, J. F. Bergoz
BERGOZ Instrumentation, Saint Genis Pouilly
- L. Ducimetière, E. Vossenberg
CERN, Geneva
| |
The LHC beam dumping system must protect the LHC machine from damage by reliably and safely extracting and absorbing the circulating beams when requested. Two sets of 15 extraction kicker magnets form the main active part of this system. A separate high voltage pulse generator powers each magnet. Because many failures are deemed catastrophic, the magnets and generators are continuously surveyed in order to generate a failsafe beam abort as soon as an internal fault is detected. Amongst these surveillance systems, wideband current transformers have been designed to detect any erratic starts in one of the generators. The current transformers were developed in collaboration with industry. To minimize losses, high-resistivity cobalt alloy was chosen for the cores. The annealing techniques originally developed for LEP beam current measurement in collaboration between CERN and industry allowed to extend the frequency response beyond that of traditional core materials. The paper shows the results obtained, exposes the problems encountered with shielding, conductor position sensitivity, load resistor technology and their solutions.
|
|
|
|