Bubble Technology Industries Inc.

Petawawa, Canada

Bubble Technology Industries Inc.

Petawawa, Canada
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Patent
Bubble Technology Industries Inc. | Date: 2016-08-26

This invention describes a remmeter that is based on the use of an assembly comprising two or more different-sized hydrogenous moderators, each hydrogenous moderator incorporating a hydrogenous spectroscopic fast neutron detector and a thermal neutron detector in order to provide more accurate neutron dosimetry across a wide range of neutron energies (thermal neutrons to >15 MeV) in a form factor that is lighter than conventional remmeters. The new remmeter utilizes the principle of spectral dosimetry, where the energy or energy distribution of the incident neutrons is first measured and then this energy information (along with the measured fluence) is used to establish the dosimetric quantity using the various fluence-to-dose conversion curves (e.g. H*(10) (ICRP (1997)), NCRP-38 (1971)). Using the method of spectral dosimetry, the large variation in response in these curves as a function of neutron energy (especially over the region 1 keV to 1 MeV) is largely mitigated through the use of the energy and fluence information, and the appropriate fluence-to-dose conversion curve to calculate the dose.


Kovaltchouk V.,Bubble Technology Industries Inc. | MacHrafi R.,University of Ontario Institute of Technology
Annals of Nuclear Energy | Year: 2011

Monte Carlo simulation of a detector response function presents a very challenging problem. The detector response functions have been calculated for different neutron and gamma detectors: 3He gas filled proportional counter, NE213 organic scintillator, BrillanCe 350 or LaCl3(Tl), and an ionization chamber with mixed gas composition. MCNPX code was used for simulations. The simulations were done with different neutron and gamma energies. The effects of neutron scattering, wall effects, recoil continua and contribution from charged particles have been included. The detector response function for the NE213 organic scintillator was obtained with consideration of light output curves of different products of neutron reactions with materials of the scintillator. The simulated data has been compared with experiments. © 2010 Elsevier Ltd. All rights reserved.


PubMed | University of Ontario Institute of Technology, Russian Academy of Sciences, Bubble Technology Industries Inc. and RSC Energia
Type: Journal Article | Journal: Radiation protection dosimetry | Year: 2016

Bubble detectors have been used to characterise the neutron dose and energy spectrum in several modules of the International Space Station (ISS) as part of an ongoing radiation survey. A series of experiments was performed during the ISS-34, ISS-35, ISS-36 and ISS-37 missions between December 2012 and October 2013. The Radi-N2 experiment, a repeat of the 2009 Radi-N investigation, included measurements in four modules of the US orbital segment: Columbus, the Japanese experiment module, the US laboratory and Node 2. The Radi-N2 dose and spectral measurements are not significantly different from the Radi-N results collected in the same ISS locations, despite the large difference in solar activity between 2009 and 2013. Parallel experiments using a second set of detectors in the Russian segment of the ISS included the first characterisation of the neutron spectrum inside the tissue-equivalent Matroshka-R phantom. These data suggest that the dose inside the phantom is 70% of the dose at its surface, while the spectrum inside the phantom contains a larger fraction of high-energy neutrons than the spectrum outside the phantom. The phantom results are supported by Monte Carlo simulations that provide good agreement with the empirical data.


McFee J.E.,Defence R and D Canada Suffield | Faust A.A.,Defence R and D Canada Suffield | Andrews H.R.,Bubble Technology Industries Inc. | Clifford E.T.H.,Bubble Technology Industries Inc. | Mosquera C.M.,Defence R and D Canada Suffield
Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment | Year: 2013

First generation thermal neutron activation (TNA) sensors, employing an isotopic source and NaI(Tl) gamma ray detectors, were deployed by Canadian Forces in 2002 as confirmation sensors on multi-sensor landmine detection systems. The second generation TNA detector is being developed with a number of improvements aimed at increasing sensitivity and facilitating ease of operation. Among these are an electronic neutron generator to increase sensitivity for deeper and horizontally displaced explosives; LaBr3(Ce) scintillators, to improve time response and energy resolution; improved thermal and electronic stability; improved sensor head geometry to minimize spatial response nonuniformity; and more robust data processing. The sensor is described, with emphasis on the improvements. Experiments to characterize the performance of the second generation TNA in detecting buried landmines and improvised explosive devices (IEDs) hidden in culverts are described. Performance results, including comparisons between the performance of the first and second generation systems are presented. © 2013 Elsevier B.V. All rights reserved.


Smith M.B.,Bubble Technology Industries Inc. | Andrews H.R.,Bubble Technology Industries Inc. | Ing H.,Bubble Technology Industries Inc. | Koslowsky M.R.,Bubble Technology Industries Inc.
Radiation Protection Dosimetry | Year: 2015

A series of Monte-Carlo simulations has been performed in order to investigate the response of the bubble detector to monoenergetic neutrons of various energies. The work was driven by the need to better understand the energy dependence of the detector for applications in space, where the neutron spectrum has a significant component with energy of >20 MeV. The response to neutrons in the range of a few keV to 500 MeV has been calculated, and good agreement between the simulations and experimental data is demonstrated over the entire energy range. © The Author 2014. Published by Oxford University Press. All rights reserved.


Smith M.B.,Bubble Technology Industries Inc.
Radiation protection dosimetry | Year: 2013

As part of the international Matroshka-R and Radi-N experiments, bubble detectors have been used on board the ISS in order to characterise the neutron dose and the energy spectrum of neutrons. Experiments using bubble dosemeters inside a tissue-equivalent phantom were performed during the ISS-16, ISS-18 and ISS-19 expeditions. During the ISS-20 and ISS-21 missions, the bubble dosemeters were supplemented by a bubble-detector spectrometer, a set of six detectors that was used to determine the neutron energy spectrum at various locations inside the ISS. The temperature-compensated spectrometer set used is the first to be developed specifically for space applications and its development is described in this paper. Results of the dose measurements indicate that the dose received at two different depths inside the phantom is not significantly different, suggesting that bubble detectors worn by a person provide an accurate reading of the dose received inside the body. The energy spectra measured using the spectrometer are in good agreement with previous measurements and do not show a strong dependence on the precise location inside the station. To aid the understanding of the bubble-detector response to charged particles in the space environment, calculations have been performed using a Monte-Carlo code, together with data collected on the ISS. These calculations indicate that charged particles contribute <2% to the bubble count on the ISS, and can therefore be considered as negligible for bubble-detector measurements in space.


Smith M.B.,Bubble Technology Industries Inc. | Achtzehn T.,Bubble Technology Industries Inc. | Andrews H.R.,Bubble Technology Industries Inc. | Clifford E.T.H.,Bubble Technology Industries Inc. | And 2 more authors.
IEEE Transactions on Nuclear Science | Year: 2013

The response of Cs2LiYCl6:Ce (CLYC) scintillator material to fast neutrons has been measured using a Van de Graaff accelerator. Beams of monoenergetic neutrons in the energy range 0.359 MeV to 4.703 MeV were used to irradiate a 9 mm × 9.5 mm × 12 mm CLYC crystal. Following pulse-shape discrimination to separate neutron and gamma-ray events, peaks are observed in the neutron spectrum and assigned to fast-neutron events in the scintillator. One of the peaks is interpreted as being due to the 35Cl(n, p)35S reaction, and it is shown that the proton energy released in this reaction varies linearly with the energy of the incoming neutron. The linearity of the response may enable CLYC to be used for fast-neutron spectroscopy with well defined spectral peaks. The response of CLYC to thermal neutrons and gamma rays is well known, and the material has potential for simultaneous thermal-neutron detection, fast-neutron spectroscopy, and gamma-ray spectroscopy. © 1963-2012 IEEE.


McFee J.E.,Defence RandD Canada Suffield | Faust A.A.,Defence RandD Canada Suffield | Andrews H.R.,Bubble Technology Industries Inc. | Clifford E.T.H.,Bubble Technology Industries Inc. | Mosquera C.M.,Defence RandD Canada Suffield
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2012

Defence R&D Canada - Suffield and Bubble Technology Industries have been developing thermal neutron activation (TNA) sensors for detection of buried bulk explosives since 1994. First generation sensors, employing an isotopic source and NaI(Tl) gamma ray detectors, were deployed by Canadian Forces in 2002 as confirmation sensors on the ILDS teleoperated, vehicle-mounted, multi-sensor anti-tank landmine detection systems. The first generation TNA could detect anti-tank mines buried 10 cm or less in no more than a minute, but deeper mines and those significantly displaced horizontally required considerably longer times. Mines as deep as 30 cm could be detected with long counting times (1000 s). The second generation TNA detector is being developed with a number of improvements aimed at increasing sensitivity and facilitating ease of operation. Among these are an electronic neutron generator to increase sensitivity for deeper and horizontally displaced explosives; LaBr3(Ce) scintillators, to improve time response and energy resolution; improved thermal and electronic stability; improved sensor head geometry to minimize spatial response nonuniformity; and more robust data processing. This improved sensitivity can translate to either decreased counting times, decreased minimum detectable explosive quantities, increased maximum sensor-to-target displacement, or a trade off among all three. Experiments to characterize the performance of the latest generation TNA in detecting buried landmines and IEDs hidden in culverts were conducted during 2011. This paper describes the second generation system. The experimental setup and methodology are detailed and preliminary comparisons between the performance of first and second generation systems are presented. © 2012 SPIE.


Patent
Bubble Technology Industries Inc. | Date: 2015-11-27

Described is a system and method for detecting contaminants using a flexible Surface Enhanced Raman Spectroscopy (SERS) substrate. The contaminant is collected on a flexible SERS substrate and directly interrogated with a Raman Spectrometer to obtaining a SERS emission spectrum for the contaminant. The obtained spectrum can be compared to a library of SERS signatures to identify the contaminant.


Drouin B.J.,Jet Propulsion Laboratory | Pearson J.C.,Jet Propulsion Laboratory | Dick M.J.,Bubble Technology Industries Inc.
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2010

This response describes the authors' reaction to a critique of recent work on the ultracold physics of water. The possibility of spin-selective adsorption occurring in the context of the collisional cooling experiment is discussed. © 2010 The American Physical Society.

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