| 1. |
- Andersen, Ken, et al.
(författare)
-
B-10 multi-grid proportional gas counters for large area thermal neutron detectors
- 2013
-
Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - : Elsevier BV. - 0167-5087 .- 0168-9002 .- 1872-9576. ; 720, s. 116-121
-
Tidskriftsartikel (refereegranskat)abstract
- He-3 was a popular material in neutrons detectors until its availability dropped drastically in 2008. The development of techniques based on alternative convertors is now of high priority for neutron research institutes. Thin films of B-10 or (B4C)-B-10 have been used in gas proportional counters to detect neutrons, but until now, only for small or medium sensitive area. We present here the multi-grid design, introduced at the ILL and developed in collaboration with ESS for LAN (large area neutron) detectors. Typically thirty (B4C)-B-10 films of 1 mu m thickness are used to convert neutrons into ionizing particles which are subsequently detected in a proportional gas counter. The principle and the fabrication of the multi-grid are described and some preliminary results obtained with a prototype of 200 cm x 8 cm are reported; a detection efficiency of 48% has been measured at 2.5 angstrom with a monochromatic neutron beam line, showing the good potential of this new technique. (C) 2013 Elsevier B.V. All rights reserved.
|
|
| 2. |
- Birch, Jens, et al.
(författare)
-
(B4C)-B-10 Multi-Grid as an Alternative to He-3 for Large Area Neutron Detectors
- 2013
-
Ingår i: IEEE Transactions on Nuclear Science. - 0018-9499 .- 1558-1578. ; 60:2, s. 871-878
-
Tidskriftsartikel (refereegranskat)abstract
- Despite its present shortage, He-3 continues to be the most common neutron converter for detectors in neutron scattering science. However, it is obvious that the development of large area neutron detectors based on alternative neutron converters is rapidly becoming a matter of urgency. In the technique presented here, grids each comprising 28 (B4C)-B-10 layers ( each 1 mu m thick) are used to convert neutrons into ionizing particles which are subsequently detected in proportional gas counters. The total active area of the prototype is 8 cm x 200 cm. To instrument this detector 4.6 m(2) of B-10-enriched boron carbide were coated onto aluminium blades using a DC magnetron sputtering machine. Characterization of the prototype showed neutron efficiency to be epsilon(n) = 46.8% for 2.5 angstrom neutrons, which is in line with expectations from MC simulation. This result demonstrates the potential of this technique as alternative to He-3-based position sensitive detectors.
|
|
| 3. |
- Khaplanov, Anton, et al.
(författare)
-
Investigation of gamma-ray sensitivity of neutron detectors based on thin converter films
- 2013
-
Ingår i: Journal of Instrumentation. - 1748-0221. ; 8
-
Tidskriftsartikel (refereegranskat)abstract
- Currently, many detector technologies for thermal neutron detection are in development in order to lower the demand for the rare He-3 gas. Gas detectors with solid thin film neutron converters readout by gas proportional counter method have been proposed as an appropriate choice for applications where large area coverage is necessary. In this paper, we investigate the probability for gamma-rays to generate a false count in a neutron measurement. Simulated results are compared to measurement with B-10 thin film prototypes and a He-3 detector. It is demonstrated that equal gamma-ray rejection to that of He-3 tubes is achieved with the new technology. The arguments and results presented here are also applicable to gas detectors with converters other than solid B-10 layers, such as Li-6 layers and (BF3)-B-10 gas.
|
|
