Search results for "scintillation"
showing 10 items of 145 documents
Der Zerfall des 2,4-sec100Nb
1972
The nuclide100Nb was produced by irradiation of enriched100Mo targets with 14 MeV-neutrons, and its decay properties were investigated employing scintillation and semiconductor spectrometers and coincidence techniques. A half-life of 2.4±0.3 sec and aQ β-value of 5.8±0.2 MeV were found. From 27 gamma-rays, 20 transitions, representing 95% of the observed gamma-ray intensity, could be placed in a decay scheme comprising 10 excited states of100Mo.
Study of scintillation light collection, production and propagation in a 4 tonne dual-phase LArTPC
2020
The $3 \times 1 \times 1$ m$^3$ demonstrator is a dual phase liquid argon time projection chamber that has recorded cosmic rays events in 2017 at CERN. The light signal in these detectors is crucial to provide precise timing capabilities. The performances of the photon detection system, composed of five PMTs, are discussed. The collected scintillation and electroluminescence light created by passing particles has been studied in various detector conditions. In particular, the scintillation light production and propagation processes have been analyzed and compared to simulations, improving the understanding of some liquid argon properties.
The Crystal Barrel data acquisition system
1992
The main detector components of the Crystal Barrel (CBAR) experiment at the Low Energy Antiproton Ring (LEAR) at CERN are two proportional wire chambers, a jet drift chamber and an electromagnetic calorimeter composed of 1380 CsI(Tl) crystals, with a total of 4380 analog channels. A description is given of the use of distributed VME-based microcomputers to collect data from the various subdetectors and to merge the full event information in a global event builder. At this level the data are transferred to a mu VAX for tape storage and monitoring. >
Quantitative Determination of Renal 99mTc-MAG3 Clearance. A Comparison of Results Acquired Simultaneously in Whole Body Geometry and with a Gamma Cam…
1997
289 patients were simultaneously investigated with a partially shielded whole body counter (Oberhausen) and in camera technique to correlate the values of the MAG3-clearance. Good correlation was found for the often used times schedules of taking blood samples. Late blood samples increase high clearance values in both methods slighly. The shape of the ROI has no influence using camera technique. We conclude, that camera technique can replace the Oberhausen method with a partially shielded whole body counter.
<title>Studies of the activation background in CsI(Tl) detectors</title>
1993
CsI scintillation crystals are widely used as detection in (gamma) -ray astronomy observations. In the MeV energy region, one of the most important background sources in CsI is the (beta) decays induced in the crystal by cosmic ray protons and their secondaries. One recent idea for reducing this background is to use discrete detector arrays to reject the large amount of localized (beta) decay events. Two experiments were carried out with 1 cm3 CsI crystals bombarded with energetic proton beams and fast/thermal neutrons, with the aim of evaluating the effectiveness of this method in pixelated (1 cm3) CsI detectors. The ratio of the number of decays resulting in single site and multiple site …
Rayleigh scattering of linear alkylbenzene in large liquid scintillator detectors.
2015
Rayleigh scattering poses an intrinsic limit for the transparency of organic liquid scintillators. This work focuses on the Rayleigh scattering length of linear alkylbenzene (LAB), which will be used as the solvent of the liquid scintillator in the central detector of the Jiangmen Underground Neutrino Observatory. We investigate the anisotropy of the Rayleigh scattering in LAB, showing that the resulting Rayleigh scattering length will be significantly shorter than reported before. Given the same overall light attenuation, this will result in a more efficient transmission of photons through the scintillator, increasing the amount of light collected by the photosensors and thereby the energy…
Performance study of the fast timing Cherenkov detector based on a microchannel plate PMT
2017
Prototype of the fast timing Cherenkov detector, applicable in high-energy collider experiments, has been developed basing on the modified Planacon XP85012 MCP-PMT and fused silica radiators. We present the reasons and description of the MCP-PMT modification, timing and amplitude characteristics of the prototype including the summary of the detector's response on particle hits at oblique angles and MCP-PMT performance at high illumination rates.
Measurements of underlying-event properties using neutral and charged particles in pp collisions at root s=900 GeV and root s=7 TeV with the ATLAS de…
2011
We present first measurements of charged and neutral particle-flow correlations in pp collisions using the ATLAS calorimeters. Data were collected in 2009 and 2010 at centre-of-mass energies of 900 GeV and 7 TeV. Events were selected using a minimum-bias trigger which required a charged particle in scintillation counters on either side of the interaction point. Particle flows, sensitive to the underlying event, are measured using clusters of energy in the ATLAS calorimeters, taking advantage of their fine granularity. No Monte Carlo generator used in this analysis can accurately describe the measurements. The results are independent of those based on charged particles measured by the ATLAS …
Technical design of the phase I Mu3e experiment
2021
Nuclear instruments & methods in physics research / A 1014, 165679 (2021). doi:10.1016/j.nima.2021.165679
Mitigation of backgrounds from cosmogenic 137 Xe in xenon gas experiments using 3 He neutron capture
2020
[EN] Xe-136 is used as the target medium for many experiments searching for 0 nu beta beta. Despite underground operation, cosmic muons that reach the laboratory can produce spallation neutrons causing activation of detector materials. A potential background that is difficult to veto using muon tagging comes in the form of Xe-137 created by the capture of neutrons on Xe-136. This isotope decays via beta decay with a half-life of 3.8 min and a Q(beta) of similar to 4.16 MeV. This work proposes and explores the concept of adding a small percentage of He-3 to xenon as a means to capture thermal neutrons and reduce the number of activations in the detector volume. When using this technique we f…