2,466 research outputs found
Simulation of laser-Compton cooling of electron beams for future linear colliders
We study a method of laser-Compton cooling of electron beams for future
linear colliders. Using a Monte Carlo code, we evaluate the effects of the
laser-electron interaction for transverse cooling. The optics with and without
chromatic correction for the cooling are examined. The laser-Compton cooling
for JLC/NLC at GeV is considered.Comment: 18 pages, 12 figures, 21st ICFA Beam Dynamics Workshop on Laser-Beam
Interactions, Stony Brook, New York, June 11-15, 200
On the basic mechanism of Pixelized Photon Detectors
A Pixelized Photon Detector (PPD) is a generic name for the semiconductor
devices operated in the Geiger-mode, such as Silicon PhotoMultiplier and
Multi-Pixel Photon Counter, which has high photon counting capability. While
the internal mechanisms of the PPD have been intensively studied in recent
years, the existing models do not include the avalanche process. We have
simulated the multiplication and quenching of the avalanche process and have
succeeded in reproducing the output waveform of the PPD. Furthermore our model
predicts the existence of dead-time in the PPD which has never been numerically
predicted. For serching the dead-time, we also have developed waveform analysis
method using deconvolution which has the potential to distinguish neibouring
pulses precisely. In this paper, we discuss our improved model and waveform
analysis method.Comment: 4pages, 5figures, To appear in the proceedings of 5th International
Conference on New Developments in Photodetection (NDIP08), Aix-les-Bains,
France, 15-20 Jun 200
Performance of Multi-Pixel Photon Counters for the T2K near detectors
We have developed a Multi-Pixel Photon Counter (MPPC) for the neutrino
detectors of T2K experiment. About 64,000 MPPCs have been produced and tested
in about a year. In order to characterize a large number of MPPCs, we have
developed a system that simultaneously measures 64 MPPCs with various bias
voltage and temperature. The performance of MPPCs are found to satisfy the
requirement of T2K experiment. In this paper, we present the performance of
17,686 MPPCs measured at Kyoto University.Comment: 15 pages, 14 figure
Small Angle Crab Compensation for LHC IR Upgrade
A small angle crab scheme is being considered for the LHC luminosity upgrade. In this paper we present a 400MHz superconducting cavity design and discuss the pertinent RF challenges. We also present a study on the beam-beam performance and proton-beam emittance growth in the presence of crab compensation, with RF noise sources
Beam-beam simulation code BBSIM for particle accelerators
A highly efficient, fully parallelized, six-dimensional tracking model for
simulating interactions of colliding hadron beams in high energy ring colliders
and simulating schemes for mitigating their effects is described. The model
uses the weak-strong approximation for calculating the head-on interactions
when the test beam has lower intensity than the other beam, a look-up table for
the efficient calculation of long-range beam-beam forces, and a self-consistent
Poisson solver when both beams have comparable intensities. A performance test
of the model in a parallel environment is presented. The code is used to
calculate beam emittance and beam loss in the Tevatron at Fermilab and compared
with measurements. We also present results from the studies of two schemes
proposed to compensate the beam-beam interactions: a) the compensation of
long-range interactions in the Relativistic Heavy Ion Collider (RHIC) at
Brookhaven and the Large Hadron Collider (LHC) at CERN with a current-carrying
wire, b) the use of a low energy electron beam to compensate the head-on
interactions in RHIC
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