| Paper |
Title |
Other Keywords |
Page |
| TUBZ04 |
Experimental Studies of Targets and Collimators for High Intensity Beams
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target, proton, radiation, isotope-production |
143 |
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- N. Simos, H. G. Kirk, J. G. O Conor
BNL, Upton, Long Island, New York
- K. T. McDonald
PU, Princeton, New Jersey
- N. V. Mokhov
Fermilab, Batavia, Illinois
- L. P. Trung
Stony Brook University, Stony Brook
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Intense muon or neutrino beams require high-performance targets intercepting multi MW proton beams. To achieve it one must push the envelope of the current knowledge regarding material behavior and endurance for both short and long exposure. It is also true for collimator structures intercepting the halo of the intense beam under normal or the entire beam during off-normal conditions. The limitations of most materials in playing such pivotal roles have led to an extensive search and experimentation with new alloys and composites that, at first glance, appear to possess the right combination of properties satisfying target and /or collimation requirements. In this study, a number of new and “smart” materials are experimentally evaluated for resilience to radiation damage and potential use in target and collimation schemes. These include targets for the muon collider and the neutrino superbeam as well as LHC collimation. Results of the on-going experimental effort under way at BNL and involving heavy irradiation of candidate materials using 200 MeV proton beams and post-irradiation analysis for irradiation damage assessment will be presented.
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| WEAZ04 |
Beam-Induced Damage to the Tevatron Components and What Has Been Done About It
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vacuum, kicker, proton, dipole |
205 |
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- N. V. Mokhov, P. Czarapata, A. I. Drozhdin, D. Still
Fermilab, Batavia, Illinois
- V. Samulyak
BNL, Upton, Long Island, New York
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The Tevatron collimators and magnets were damaged and two thirds of the superconducting ring were quenched on December 5, 2003, induced by a failure in the CDF Roman Pot detector positioning at the end of a 2-TeV proton-antiproton colliding beam store. Analysis of a failure in the abort kicker AC distribution, and detailed modeling of a misbehaved beam dynamics, induced energy deposition and ablation process in the collimator material, have provided a good understanding of the event. The improvements to the detectors, Tevatron quench protection and beam loss monitor systems to avoid such an accident in the future are described.
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| WEBZ03 |
A New High Rate Charged Particles Detector
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hadron, kaon, scattering, proton |
256 |
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- Ph. Legou
CEA, Gif-sur-Yvette
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Sextant is a new Beam Spectrometer. This detector is based on a Time Projection Chamber(TPC)principle, using a gaseous detector called Micromegas. Thus, we have a better efficiency, with the minimum amount of material in the way of the beam. Moreover, using the TPC technique, the Mesh of the detector is positioned outside the high intensity region covered by the beam. Peformances of this detecor are very good in a high intensity hadron beams (spatial resolution : 70μm and time resolution 600ps). The integration of the front end on the PCB led to a very low noise for the entire detector. Main characteristics of the preamplifier are 1ns of rise time and a very low noise, lower than 600 μV rms. Sextant is an evolution of KABES, a beam spectrometer on NA 48II at CERN. This concept have shown very good performances and robustness.
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| THAW04 |
Experimental Characterization of the “1st Pulse” e-p Instability at the LANL PSR
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electron, accumulation, diagnostics, injection |
311 |
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- R. J. Macek, A. A. Browman, D. H. Fitzgerald, R. C. McCrady, T. Spickermann, J. Zaugg
LANL, Los Alamos, New Mexico
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A puzzling aspect of the e-p instability at PSR is the so called “1st Pulse” instability phenomenon. It shows up on the first beam pulse after a period (10 to 30 minutes or more) of beam off time. This pulse has a significantly lower threshold than subsequent beam pulses that follow with the standard time separation. While the standard PSR operation for Lujan Center operation is unaffected by this phenomenon, it does interfere with some high intensity, single pulse experiments using PSR beam. We will summarize the present experimental data characterizing this phenomenon as compared with the typical e-p instability observed at higher repetition rates at PSR and discuss some possible explanations.
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| THAZ02 |
SNS Commissioning Strategies and Tuneup Algorithms
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linac, target, injection, quadrupole |
283 |
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- J. Galambos
ORNL, Oak Ridge, Tennessee
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The Spallation Neutron Source (SNS) has been recently commissioned. The strategies for the initial beam commissioning of the superconducting linac (SCL) and storage ring will be discussed. The SCL commissioning had to accommodate an unanticipated wide range of cavity performance, compared to design expectations. Methods for setting cavity phases and determination of amplitudes will be discussed. The ring commissioning involved the usual establishment of a circulating beam, and then measurement and correction the tune and beta functions, all with a low intensity beam. Then the gradual increase of beam intensity and commissioning of RF and phase space painting were investigated. The methods to accomplish these tasks will be discussed. In general, the first order beam behavior is well understood. Key factors in the successful commissioning are: flexibility in accommodating beam conditions that are different from the design, good communication between the different groups, and attention to detail. Examples for these factors will be emphasized.
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| THBZ02 |
Commissioning strategies for J-PARC linac and L3BT
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linac, injection, beam-transport, quadrupole |
347 |
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- M. Ikegami, S. Lee
KEK, Ibaraki
- Y. Kondo, T. Ohkawa
JAEA, Ibaraki-ken
- A. Ueno
JAEA/LINAC, Ibaraki-ken
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We plan to start the beam commissioning of J-PARC linac with reduced energy of 181 MeV in the end of this year. Detailed commissioning strategies for the linac and the succeeding beam transport line, to which we refer as L3BT or Linac-to-3-GeV-synchrotron Beam Transport, will be presented in this talk. The emphasis will be put on the commissioning procedures for two debuncher cavities and a transverse collimator system located in L3BT, because they are key elements in determining the final beam quality at the injection point to the succeeding 3-GeV synchrotron. The unique design and features of the collimator system are also presented.
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