Wavelength-shifting-fiber scintillation detectors for thermal neutron imaging at SNS

Wang, CL; Clonts, L.G.; Cooper, Ron; Crow, Lowell; Diawara, Y.; Ellis, Elizabeth D.; Funk, L.; Hodges, J. P.; Richards, John D.; Riedel, Richard A.; Hayward, Jason P.; Workman, H. E.; Kline, C.

doi:10.1109/nssmic.2011.6152489

Cited by 15 publications

(14 citation statements)

References 9 publications

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“…This technology is now widely used and well established. The two single-crystal time-of-flight diffractometers SENJU [3,4] and iBIX [5] at J-PARC, as well as the engineering diffractometer VULCAN [6,7] and the powder diffractometer POWGEN3 [8] in ORNL are examples of instruments currently in operation which are equiped with detectors based on this technology. Up to now, all the detectors of this kind use photomultiplier tubes (PMTs) or multi-anode photomultiplier tubes (MaPMTs) to read out the WLS fibers.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of two thermal neutron detection units consisting of ZnS/ 6 LiF scintillating layers with embedded WLS fibers read out with a SiPM

Mosset

Stoykov

Greuter

et al. 2014

Nuclear Instruments and Methods in Physics Research Section A:

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Two single channel detection units for thermal neutron detection are investigated in a neutron beam. They consist of two ZnS/ 6 LiF scintillating layers sandwiching an array of WLS fibers. The pattern of this units can be repeated laterally and vertically in order to build up a one dimensional position sensitive multi-channel detector with the needed sensitive surface and with the required neutron absorption probability. The originality of this work arises from the fact that the WLS fibers are read out with SiPMs instead of the traditionally used PMTs or MaPMTs. The signal processing system is based on a photon counting approach. For SiPMs with a dark count rate as high as 0.7 MHz, a trigger efficiency of 80% is achieved together with a system background rate lower than 10 −3 Hz and a dead time of 30 µs. No change of performance is observed for neutron count rates of up to 3.6 kHz.

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Section: Introductionmentioning

confidence: 99%

Evaluation of two thermal neutron detection units consisting of ZnS/ 6 LiF scintillating layers with embedded WLS fibers read out with a SiPM

Mosset

Stoykov

Greuter

et al. 2014

Nuclear Instruments and Methods in Physics Research Section A:

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“…Two fibers with a center-to-center distance of 2.5 mm are combined to define an x-column. Two fiber mapping methods (v.2 and v.3) and the associated digital readout system were described previously, 7 and their schematic plots are shown in Fig. 1.…”

Section: Fiber Encoding and Readoutmentioning

confidence: 99%

“…appears as periodic redundant side peaks or valleys in the background profile as well as in aperture (or slit) images. 7 Several adjustable parameters were applied in the neutron position determination algorithms to mitigate the ghosting, but performance was unsatisfactory. Although small, ghosting effects may undermine the full potential of WLS fiber detectors for certain experiments performed at VULCAN, and possibly for other instruments, for which a smoothly varying, unstructured intrinsic background across the detector is a prerequisite for reliable results in the powder diffraction studies such as structure refinements of materials with multiphase, minority phases, or superlattices.…”

Section: Introductionmentioning

confidence: 99%

Elimination of ghosting artifacts from wavelength-shifting fiber neutron detectors

Wang

Clonts

Diawara

et al. 2013

Review of Scientific Instruments

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Misassignment of neutron position (ghosting) produces artifacts which have been observed in wavelength-shifting (WLS) fiber detectors developed for time-of-flight (TOF) neutron powder diffraction. In position-sensitive detectors (PSDs) with WLS fiber encoding, thermal and cold neutrons interact with a monolithic (6)LiF/ZnS:Ag scintillator screen, and scintillation photons are generated and transported through the crossed fibers to photomultipliers (PMTs). The neutron position is determined by photon counts in the PMTs within a preset time window. Ghosting occurs when neutrons hit the group boundaries of two neighboring PMTs for x-position multiplexing, which is modeled as resulting from a long travel length (about 3-5 mm) of a small number of scintillation photons. This model is supported by the change observed in aperture images when the threshold number for photon-pulses was adjusted for neutron event determination. When the threshold number of photon-pulses was set above 10 for each PMT, the ghost peaks in the aperture images and TOF spectra of powder diffraction were strongly suppressed or completely eliminated, and the intrinsic background levels of the WLS detectors were significantly reduced. Our result indicates that WLS fiber detector is a promising alternative for (3)He PSDs for neutron scattering.

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“…For many years 3 He-based detectors have been dominant in the field of neutron scattering science, as they satisfied scientific requirements and 3 He was available in sufficient quantities at an affordable price. The situation has changed in recent years due to the worldwide 3 He crisis [1,2] that necessitated the development of alternative neutron detector technologies based on 10 B 4 C [3,4,5,6,7,8,9], 6 LiF [10,11,12] and scintillators [13,14,15,16,17,18,19,20].…”

Section: Introductionmentioning

confidence: 99%

Performance evaluation of the Boron Coated Straws detector with Geant4

Klausz

Kanaki

Zagyvai

et al. 2019

Nuclear Instruments and Methods in Physics Research Section A:

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The last decade has witnessed the development of several alternative neutron detector technologies, as a consequence of upcoming neutron sources and upgrades, as well the world-wide shortage of 3 He. One branch of development is the family of 10 B-based gaseous detectors. This work focuses on the boron coated straws (BCS) by Proportional Technologies Inc., a commercial solution designed for use in homeland security and neutron science. A detailed Geant4 simulation study of the BCS is presented, which investigates various aspects of the detector performance, e.g. efficiency, activation, absorption and the impact of scattering on the measured signal. The suitability of the BCS detector for Small Angle Neutron Scattering (SANS) and direct chopper spectrometry is discussed.

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Wavelength-shifting-fiber scintillation detectors for thermal neutron imaging at SNS

Cited by 15 publications

References 9 publications

Evaluation of two thermal neutron detection units consisting of ZnS/ 6 LiF scintillating layers with embedded WLS fibers read out with a SiPM

Evaluation of two thermal neutron detection units consisting of ZnS/ 6 LiF scintillating layers with embedded WLS fibers read out with a SiPM

Elimination of ghosting artifacts from wavelength-shifting fiber neutron detectors

Performance evaluation of the Boron Coated Straws detector with Geant4

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