Proof of principle of a high-spatial-resolution, resonant-response γ-ray detector for Gamma Resonance Absorptionin 14N

Journal of Instrumentation (Impact Factor: 1.4). 03/2011; 6(02). DOI: 10.1088/1748-0221/6/02/P02008
Source: arXiv


The development of a mm-spatial-resolution, resonant-response detector based
on a micrometric glass capillary array filled with liquid scintillator is
described. This detector was developed for Gamma Resonance Absorption (GRA) in
14N. GRA is an automatic-decision radiographic screening technique that
combines high radiation penetration (the probe is a 9.17 MeV gamma ray) with
very good sensitivity and specificity to nitrogenous explosives. Detailed
simulation of the detector response to electrons and protons generated by the
9.17 MeV gamma-rays was followed by a proof-of-principle experiment, using a
mixed gamma-ray and neutron source. Towards this, a prototype capillary
detector was assembled, including the associated filling and readout systems.
Simulations and experimental results indeed show that proton tracks are
distinguishable from electron tracks at relevant energies, on the basis of a
criterion that combines track length and light intensity per unit length.

39 Reads
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    • "For fixed target experimental activities, a focused beam is desired in order to obtain higher interaction rates on a target. Such a setup enables applications in material analysis such as PIGE/PIXE [2] [3] [4] and GRNA [5] [6] [7]. Another interesting option is the use of the envisioned PMQ system for beam transfer lines (BTL), where minimal beam divergence is required instead of minimal beam size. "
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    ABSTRACT: A compact adjustable focusing system for a 2 MeV H- RFQ Linac is designed, constructed and tested based on four permanent magnet quadrupoles (PMQ). A PMQ model is realised using finite element simulations, providing an integrated field gradient of 2.35 T with a maximal field gradient of 57 T/m. A prototype is constructed and the magnetic field is measured, demonstrating good agreement with the simulation. Particle track simulations provide initial values for the quadrupole positions. Accordingly, four PMQs are constructed and assembled on the beam line, their positions are then tuned to obtain a minimal beam spot size of (1.2 x 2.2) mm^2 on target. This paper describes an adjustable PMQ beam line for an external ion beam. The novel compact design based on commercially available NdFeB magnets allows high flexibility for ion beam applications.
    Journal of Instrumentation 11/2012; 8(02). DOI:10.1088/1748-0221/8/02/P02001 · 1.40 Impact Factor
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    • "In 2005 the Soreq, PTB and Bern University collaboration investigated a capillary array of 20 µm in diameter fibres, developed by the CHORUS collaboration at CERN. The capillaries were filled with high-refractive-index liquid scintillator developed at Soreq for a Gamma-ray Resonance Absorption (GRA) detector [8]. The detector was tested with gamma-rays and mixed gamma and neutron events, produced by radioactive sources. "
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    ABSTRACT: A fast-neutron imaging detector based on micrometric glass capillaries loaded with high refractive index liquid scintillator has been developed Neutron energy spectrometry is based on event-by-event detection and reconstruction of neutron energy from the measurement of the knock-on proton track length and the amount of light produced in the track. In addition, the detector can provide fast-neutron imaging with position resolution of tens of microns. The detector principle of operation, simulations and experimental results obtained with a small detector prototype are described. We have demonstrated by simulation energy spectrum reconstruction for incident neutrons in the range of 4–20 MeV. The energy resolution in this energy range was 10–15%. Preliminary experimental results of detector spectroscopic capabilities are presented
    Journal of Instrumentation 04/2012; 7(04). DOI:10.1088/1748-0221/7/04/C04021 · 1.40 Impact Factor
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    ABSTRACT: Two proton accelerators have been recently put in operation in Bern: an 18 MeV cyclotron and a 2 MeV RFQ linac. The commercial IBA 18/18 cyclotron, equipped with a specifically conceived 6 m long external beam line ending in a separate bunker, will provide beams for routine 18-F and other PET radioisotope production as well as for novel detector, radiation biophysics, radioprotection, radiochemistry and radiopharmacy developments. The accelerator is embedded into a complex building hosting two physics laboratories and four Good Manufacturing Practice (GMP) laboratories. This project is the result of a successful collaboration between the Inselspital, the University of Bern and private investors, aiming at the constitution of a combined medical and research centre able to provide the most cutting-edge technologies in medical imaging and cancer radiation therapy. The cyclotron is complemented by the RFQ with the primary goals of elemental analysis via Particle Induced Gamma Emission (PIGE), and the detection of potentially dangerous materials with high nitrogen content using the Gamma-Resonant Nuclear Absorption (GRNA) technique. In this context, beam instrumentation devices have been developed, in particular an innovative beam profile monitor based on doped silica fibres and a setup for emittance measurements using the pepper-pot technique. On this basis, the establishment of a proton therapy centre on the campus of the Inselspital is in the phase of advanced study.
    07/2013; 1530:189-196. DOI:10.1063/1.4812922