1,073 research outputs found
Qualification Tests of 474 Photomultiplier Tubes for the Inner Detector of the Double Chooz Experiment
The hemispherical 10" photomultiplier tube (PMT) R7081 from Hamamatsu
Photonics K.K. (HPK) is used in various experiments in particle and
astroparticle physics. We describe the test and calibration of 474 PMTs for the
reactor antineutrino experiment Double Chooz. The unique test setup at
Max-Planck-Institut f\"ur Kernphysik Heidelberg (MPIK) allows one to calibrate
30 PMTs simultaneously and to characterize the single photo electron response,
transit time spread, linear behaviour and saturation effects, photon detection
efficiency and high voltage calibration
Qualification Tests of 474 Photomultiplier Tubes for the Inner Detector of the Double Chooz Experiment
The hemispherical 10" photomultiplier tube (PMT) R7081 from Hamamatsu
Photonics K.K. (HPK) is used in various experiments in particle and
astroparticle physics. We describe the test and calibration of 474 PMTs for the
reactor antineutrino experiment Double Chooz. The unique test setup at
Max-Planck-Institut f\"ur Kernphysik Heidelberg (MPIK) allows one to calibrate
30 PMTs simultaneously and to characterize the single photo electron response,
transit time spread, linear behaviour and saturation effects, photon detection
efficiency and high voltage calibration
Qualification Tests of 474 Photomultiplier Tubes for the Inner Detector of the Double Chooz Experiment
The hemispherical 10" photomultiplier tube (PMT) R7081 from Hamamatsu
Photonics K.K. (HPK) is used in various experiments in particle and
astroparticle physics. We describe the test and calibration of 474 PMTs for the
reactor antineutrino experiment Double Chooz. The unique test setup at
Max-Planck-Institut f\"ur Kernphysik Heidelberg (MPIK) allows one to calibrate
30 PMTs simultaneously and to characterize the single photo electron response,
transit time spread, linear behaviour and saturation effects, photon detection
efficiency and high voltage calibration
Partition Pooling for Convolutional Graph Network Applications in Particle Physics
Convolutional graph networks are used in particle physics for effective event
reconstructions and classifications. However, their performances can be limited
by the considerable amount of sensors used in modern particle detectors if
applied to sensor-level data. We present a pooling scheme that uses
partitioning to create pooling kernels on graphs, similar to pooling on images.
Partition pooling can be used to adopt successful image recognition
architectures for graph neural network applications in particle physics. The
reduced computational resources allow for deeper networks and more extensive
hyperparameter optimizations. To show its applicability, we construct a
convolutional graph network with partition pooling that reconstructs simulated
interaction vertices for an idealized neutrino detector. The pooling network
yields improved performance and is less susceptible to overfitting than a
similar network without pooling. The lower resource requirements allow the
construction of a deeper network with further improved performance
The First Year IceCube-DeepCore Results
The IceCube Neutrino Observatory includes a tightly spaced inner array in the
deepest ice, called DeepCore, which gives access to low-energy neutrinos with a
sizable surrounding cosmic ray muon veto. Designed to be sensitive to neutrinos
at energies as low as 10 GeV, DeepCore will be used to study diverse physics
topics with neutrino signatures, such as dark matter annihilations and
atmospheric neutrino oscillations. The first year of DeepCore physics
data-taking has been completed, and the first observation of atmospheric
neutrino-induced cascades with IceCube and DeepCore are presented.Comment: 4 pages, 3 figures, TAUP 2011 (Journal of Physics: Conference Series
(JCPS)
A unified supernova catalogue
In this paper a new supernova catalogue containing data for 5526
extragalactic supernovae that were discovered up to 2010 December 31 is
presented. It combines several catalogues that are currently available online
in a consistent and traceable way. During the comparison of the catalogues
inconsistent entries were identified and resolved where possible. Remaining
inconsistencies are marked transparently and can be easily identified. Thus it
is possible to select a high-quality sample in a most simple way. Where
available, redshift-based distance estimates to the supernovae were replaced by
journal-refereed distances. Examples of statistical studies that are now
possible with this new catalogue are presented in this paper.Comment: 9 pages, 12 figures, catalogue is available at
http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/538/A12
Afterpulse Measurements of R7081 Photomultipliers for the Double Chooz Experiment
We present the results of afterpulse measurements performed as qualification test for 473 inner detector photomultipliers of the Double Chooz experiment. The measurements include the determination of a total afterpulse occurrence probability as well as an average time distribution of these pulses. Additionally, more detailed measurements with different light sources and simultaneous charge and timing measurements were performed with a few photomultipliers to allow a more detailed understanding of the effect. The results of all measurements are presented and discussed
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