1,126 research outputs found
A Detailed Monte-Carlo Simulation for the Belle TOF System
We have developed a detailed Monte Carlo simulation program for the Belle TOF
system. Based on GEANT simulation, it takes account of all physics processes in
the TOF scintillation counters and readout electronics. The simulation
reproduces very well the performance of the Belle TOF system, including the
dE/dx response, the time walk effect, the time resolution, and the hit
efficiency due to beam background. In this report, we will describe the Belle
TOF simulation program in detail.Comment: To be submitted to NI
The first version Buffered Large Analog Bandwidth (BLAB1) ASIC for high luminosity collider and extensive radio neutrino detectors
Future detectors for high luminosity particle identification and ultra high
energy neutrino observation would benefit from a digitizer capable of recording
sensor elements with high analog bandwidth and large record depth, in a
cost-effective, compact and low-power way. A first version of the Buffered
Large Analog Bandwidth (BLAB1) ASIC has been designed based upon the lessons
learned from the development of the Large Analog Bandwidth Recorder and
Digitizer with Ordered Readout (LABRADOR) ASIC. While this LABRADOR ASIC has
been very successful and forms the basis of a generation of new, large-scale
radio neutrino detectors, its limited sampling depth is a major drawback. A
prototype has been designed and fabricated with 65k deep sampling at
multi-GSa/s operation. We present test results and directions for future
evolution of this sampling technique.Comment: 15 pages, 26 figures; revised, accepted for publication in NIM
An imaging time-of-propagation system for charged particle identification at a super B factory
Super B factories that will further probe the flavor sector of the Standard
Model and physics beyond will demand excellent charged particle identification
(PID), particularly K/pi separation, for momenta up to 4 GeV/c, as well as the
ability to operate under beam backgrounds significantly higher than current B
factory experiments. We describe an Imaging Time-of-Propagation (iTOP) detector
which shows significant potential to meet these requirements. Photons emitted
from charged particle interactions in a Cerenkov radiator bar are internally
reflected to the end of the bar, where they are collected on a compact image
plane using photodetectors with fine spatial segmentation in two dimensions.
Precision measurements of photon arrival time are used to enhance the two
dimensional imaging, allowing the system to provide excellent PID capabilities
within a reduced detector envelope. Results of the ongoing optimization of the
geometric and physical properties of such a detector are presented, as well as
simulated PID performance. Validation of simulations is being performed using a
prototype in a cosmic ray test stand at the University of Hawaii.Comment: 3 pages, 5 figures, submitted to TIPP09 proceeding
Study of timing characteristics of a 3 m long plastic scintillator counter using waveform digitizers
A plastic scintillator bar with dimensions 300 cm x 2.5 cm x 11 cm was
exposed to a focused muon beam to study its light yield and timing
characteristics as a function of position and angle of incidence. The
scintillating light was read out at both ends by photomultiplier tubes whose
pulse shapes were recorded by waveform digitizers. Results obtained with the
WAVECATCHER and SAMPIC digitizers are analyzed and compared. A discussion of
the various factors affecting the timing resolution is presented. Prospects for
applications of plastic scintillator technology in large-scale particle physics
detectors with timing resolution around 100 ps are provided in light of the
results
Neutral B Flavor Tagging for the Measurement of Mixing-induced CP Violation at Belle
We describe a flavor tagging algorithm used in measurements of the CP
violation parameter sin2phi_1 at the Belle experiment. Efficiencies and wrong
tag fractions are evaluated using flavor-specific B meson decays into hadronic
and semileptonic modes. We achieve a total effective efficiency of $ 28.8 +-
0.6 %.Comment: 28 pages, 9 figure
Time resolution of Burle 85001 micro-channel plate photo-multipliers in comparison with Hamamatsu R2083
The CLAS detector will require improvements in its particle identification
system to take advantage of the higher energies provided by the Jefferson
Laboratory accelerator upgrade to 12 GeV. To this end, we have studied the
timing characteristics of the micro-channel plate photo-multiplier 85001 from
Burle, which can be operated in a high magnetic field environment.
For reference and comparison, measurements were also made using the standard
PMT R2083 from Hamamatsu using two timing methods.
The cosmic ray method, which utilizes three identical scintillating counters
2cmx3cmx50cm with PMs at the ends, yields 59.1(0.7)ps.
The location method of particles from radiative source with known coordiantes
has been used to compare timing resolutions of R2083 and Burle-85001.This
``coordinate method'' requires only one counter instrumented with two PMs and
it yields 59.5(0.7)ps.
For the micro-channel plate photomultiplier from Burle with an external
amplification of 10 to the signals, the coordinate method yields 130(4)ps.
This method also makes it possible to estimate the number of primary
photo-electrons.Comment: 23 pages, 13 figure
The Cherenkov Correlated Timing Detector: Beam Test Results from Quartz and Acrylic Bars
Several prototypes of a Cherenkov Correlated Timing (CCT) Detector have been
tested at the KEK-PS test beam line. We describe the results for Cherenkov
light yields and timing characteristics from quartz and acrylic bar prototypes.
A Cherenkov angle resolution is found to be 15 mrad at a propagation distance
of 100 cm with a 2 cm thick quartz bar prototype.Comment: Presented at the RICH95 workshop, Uppsala, Sweden, June/95. H.
Kichimi corresponding author. 5 pages with 9 figures. LaTex source files and
postscript figures compressed and uuencoded belo
Measurement of inclusive electron cross section in collisions at TRISTAN
We have studied open charm production in collisions with the
TOPAZ detector at the TRISTAN collider. In this study, charm
quarks were identified by electrons (and positrons) from semi-leptonic decays
of charmed hadrons. The data corresponded to an integrated luminosity of 95.3
pb at a center-of-mass energy of 58 GeV. The results are presented as
the cross sections of inclusive electron production in
collisions with an anti-tag condition, as well as the subprocess cross
sections, which correspond to resolved-photon processes. The latter were
measured by using a sub-sample with remnant jets. A comparison with various
theoretical predictions based on direct and resolved-photon processes showed
that our data prefer that with relatively large gluon contents in a photon at
small , with the next-to-leading order correction, and with a
charm-quark mass of 1.3 GeV.Comment: 26 pages, Latex format (article), 5 figures included, to be published
in Phys. Lett.
Sub-10ps Monolithic and Low-power Photodetector Readout
Recent advances in photon detectors have resulted in high-density imaging
arrays that offer many performance and cost advantages. In particular, the
excellent transit time spread of certain devices show promise to provide
tangible benefits in applications such as Positron Emission Tomography (PET).
Meanwhile, high-density, high-performance readout techniques have not kept on
pace for exploiting these developments. Photodetector readout for next
generation high event rate particle identification and time-resolved PET
requires a highly-integrated, low-power, and cost-effective readout technique.
We propose fast waveform sampling as a method that meets these criteria and
demonstrate that sub-10ps resolution can be obtained for an existing device.Comment: 12 pages, 20 figures, submitted to NIM
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