Modularized NaI(Tl) detectors in a half barrel configuration
15 Apr 1986-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment (North-Holland)-Vol. 245, Iss: 1, pp 59-70
TL;DR: In this paper, a modularized array of NaI(Tl) detectors in a half barrel configuration is presented, where 96 NaI modules are surrounded by a layer of 48 modules of scintillating glass.
Abstract: We have constructed a modularized array of NaI(Tl) detectors in a half barrel configuration that is about 75 cm long with an inner radius of 25 cm. 96 NaI modules are surrounded by a layer of 48 modules of scintillating glass which have similar dimensions to the NaI modules. Each NaI crystal was shaped as a trapezoidal pyramid and encapsulated in a 1 mm thick aluminium container with dimensions of (43 × 94) × (110 × 94) × 377 mm3. The construction and performance are described along with the gain calibration and monitoring, the beam position sensitivity, the scattering between modules, etc. The fwhm energy resolution of a 5 × 5 array of NaI modules varied from 6.5% for incident electrons at 100 MeV to 3.6% at 1000 MeV
Citations
More filters
TL;DR: In this paper, recent progress in crystal growth technology is described for typical alkali (alkali-earth) halide and oxide scintillation crystals such as NaI:Tl, CsI: Tl, Bismuth germanate (BGO), Bi4Ge3O12, Cadmium tungstate (CWO), CdWO4, and cerium-doped gadolinium silicate (GSO:Ce).
153 citations
TL;DR: In this paper, the general properties of antiproton-proton annihilation at rest are presented, with special focus on the two-meson final states, and the data exhibit remarkable dynamical selection rules: some allowed annihilation modes are suppressed by one order of magnitude with respect to modes of comparable phase-space.
97 citations
15 Feb 1991-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: In this article, a set of measured γ-ray and electron spectra with energies ranging from 1 to 30 MeV were fit to response functions calculated using Monte Carlo techniques (EGS4) to determine the energy calibration of the spectrometer and the degree of broadening required for the calculated response functions.
Abstract: Methods are evaluated for determining the energy calibration and the response of a 20 cm by 25 cm NaI detector, and for unfolding the detector response from measured spectra of 10 to 30 MV bremsstrahlung. A set of measured γ-ray and electron spectra with energies ranging from 1 to 30 MeV were fit to response functions calculated using Monte Carlo techniques (EGS4) to determine the energy calibration of the spectrometer and the degree of broadening required for the calculated response functions. For electrons, the broadened response was in excellent agreement with the measurements. For γ-rays, there was evidence of collimator-degraded photons in the measured spectra. A matrix of broadened response-functions was generated for use in unfolding bremsstrahlung spectra in the energy range of 0.2 to 35 MeV. The unfolding routine FERDO was shown to provide reliable estimates of the spectrum of photons in the bremsstrahlung beam when this response matrix was used for unfolding. Collimator effects were ignored without significantly affecting the shape of the unfolded spectrum.
14 citations
15 Jul 1988-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: In this article, the authors designed and tested a new high resolution NaI(Tl) total absorption scintillation counter, which is a cylinder composed of a 26.7 cm diameter by 55.9 cm long NaI core with a concentric 10.8 cm thick NaI annulus.
Abstract: We have designed and tested a new high resolution NaI(Tl) total absorption scintillation counter. The detector is a cylinder composed of a 26.7 cm diameter by 55.9 cm long NaI core with a concentric 10.8 cm thick NaI annulus that is divided into quadrants. The NaI detector is surrounded by a 12.7 cm thick plastic scintillator to veto both cosmic rays and events with significant shower leakage from the NaI. High uniformity of light production and collection throughout the detector is required for superior resolution. The detector has a measured resolution of 1.3% and 1.7% FWHM for 130 MeV photons and 330 MeV electrons, respectively. Computer simulations to account for loss of resolution due to pileup and energy spread of the beam indicate that the ultimate experimental resolutions at these energies are 1.2±0.1% and 1.3±0.1%. The resolutions at these two energies are at least a factor of 2 better than that of any other total absorption scintillation counter available today. Based on shower simulations, the detector is expected to have a resolution of approximately 1.3% for collimated 130–2000 MeV photons.
13 citations
15 Feb 1988-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: An array of 49 NaI(Tl) modules each 20 inch in depth and 2.5 inch in cross section has been constructed and its properties, especially energy resolution, explored for positrons in the range 20 MeV − 18 GeV as mentioned in this paper.
Abstract: An array of 49 NaI(Tl) modules each 20 inch in depth and 2.5 inch × 2.5 inch in cross section has been constructed and its properties, especially energy resolution, explored for positrons in the range 20 MeV – 18 GeV. A subsequent much larger detector, the Crystal Box, has also been constructed from 396 modules of the same cross section, but mostly 12 inch in depth, and operated as a γ-ray and positron detector in a search for rare muon decays. The calibration procedure used for the Crystal Box and its characteristic resolutions in energy, impact point and time are described.
11 citations
References
More filters
TL;DR: The γ-ray spectrum after p annihilation at rest was measured in two independent high-statistics runs as discussed by the authors, showing narrow peaks corresponding to masses of 1210, 1638, 1694 and 1771 MeV.
25 citations
TL;DR: The Cluster of 54 detector as mentioned in this paper is the predecessor of the Crystal Ball detector, which is designed for the study of electron-positron collisions at colliding beam facilities, and it has been successfully tested.
Abstract: A prototye NaI(Tl) detector (the Cluster of 54) of spherical geometry subtending a solid angle of 7.5% of 4? at its center, has recently been assembled and tested. This detector consisted of 54 close-packed but optically isolated NaI(Tl) modules and the associated electronic circuitry. The Cluster of 54 is the predecessor of an almost complete spherical detector, the Crystal Ball, which will cover 94% of 4?. The latter detector is now under construction and is especially designed for the study of ?-rays produced in electron-positron collisions at colliding beam facilities. This article will outline the mechanical, optical, and electronic assembly of the prototype system. Cluster of 54 test data will be presented.
21 citations
TL;DR: In this article, the decay properties of baryonia are discussed and widths are estimated for L = 1 states, and several novel characteristics which are to be anticipated are pointed out.
14 citations
TL;DR: The use of modularized NaI(Tl) detectors in the study of a new spectroscopy of?-rays in high energy physics is outlined in this article. And the properties of detector arrays made up of 20-in-depth polyscin modules 20 in. deep and of hexagonal cross section are described.
Abstract: The properties of detector arrays made up of NaI(Tl) Polyscin modules 20 in. deep and of hexagonal cross section and the development of a Monte Carlo code of general use in the design of such detectors are described. The use of modularized NaI(Tl) detectors in the study of a new spectroscopy of ?-rays in high energy physics is outlined.
11 citations
TL;DR: A scintillator glass (type : SCG1B) detector of 14 × 14 × 40 cm3 gives an energy resolution (fwhm) of 6.5%/E −1 2 for low energy electrons as mentioned in this paper.
11 citations