TY - JOUR
AU - Murata,, Isao
AB - Abstract A novel optically stimulated luminescence (OSL) detector containing isotopically enriched boron was developed for thermal neutron dosimetry. Alumina containing isotopically enriched boron (Al2O3:B) was synthesised by the sol-gel method. The Al2O3:B was annealed up to ~1800 K. For X-ray diffractometer (XRD) analysis, the diffraction pattern of the Al2O3:B had reflex peaks corresponding to α-Al2O3. The sensitivity of Al2O3:B to photons was slightly 2% of that of a commercial Al2O3:C. The Al2O3:B detector had satisfactory linearity in X-ray dose measurement. A thermal neutron field was constructed using a 241Am-Be neutron source and graphite blocks. A pair of Al2O3:10B and Al2O3:11B detectors were set in the thermal neutron field. The response of Al2O3:10B was larger than that of Al2O3:11B owing to the 10B(n,α)7Li reactions. The sensitivity of Al2O3:10B to thermal neutrons was estimated to be two orders less than the photon sensitivity. Therefore, the pair of Al2O3:10B and Al2O3:11B detectors were useful for thermal neutron dosimetry. INTRODUCTION Neutron dosimetry for radiation workers is important in nuclear facilities such as nuclear reactors and high energy accelerator facilities(1–3). Recently, boron neutron capture therapy (BNCT) promises to be an effective advanced radiation therapy. A precise neutron dosimetry in the BNCT is important for patients and radiation workers(4). Solid-state nuclear track detectors (SSNTDs) with radiators are applied for neutron dosimetries(5). However, chemical etching and optical microscopy are time-consuming jobs for counting the etch pits on the SSNTD. Some thermoluminescent detectors (TLDs) have high sensitivity to thermal neutrons. The thermal neutron detection of the TLDs is based on the production of alpha particles upon neutron capture reactions of 6Li (940 barns) or 10B (3840 barns) nuclei. A pair of TLD-600 (6LiF) and TLD-700 (7LiF) is applied for a neutron dosimetry(6). The TLD-600 is sensitive to thermal neutrons and gamma rays. The TLD-700 is used only to record gamma ray exposure. The thermal neutron dose is evaluated for the difference between the readout values of the TLDs in the pair. For fast neutron detection, albedo neutrons are generally detected by moderating and scattering the fast neutrons in a human body or construction materials(7). Typical optically stimulated luminescence (OSL) detectors such as Al2O3:C(8, 9) and BeO(10, 11) have been applied worldwide for personal dosimetry and environmental monitoring. The OSL technique in the personal dosimetry of photons and beta rays has some advantages for a wide range of linearity, high sensitivity and precise readout. However, the Al2O3:C and the BeO detectors have low sensitivity to thermal neutrons. Some researchers have proposed neutron-sensitive OSL detectors. Kobayashi et al. developed a neutron image technique with the Al2O3:C sheets and Gd2O3 neutron converters(12). Yukihara et al. investigated the effects of neutron converters such as 6LiF, 6Li2CO3 and Gd2O3 powders for the Al2O3:C detector(13). Passmore et al. developed an Al2O3:C material coated with 6Li2CO3(14). The neutron-sensitive technique with the neutron converters maintains the conventional OSL properties of the Al2O3:C detector. However, both grain sizes of the OSL materials and the neutron converters strongly depend on neutron sensitivity owing to the fact that the ranges of alpha particles produced from (n,α) reactions are a few tens of micrometres. Numerous methods for synthesising Al2O3 material have been proposed for many applications(15, 16). The sol-gel method is popular because of its simple preparation and high reproducibility(15). In a previous report, a binary oxide system, Al2O3/B2O3, was successfully synthesised by the sol-gel technique from aluminium isopropoxide (Al[OCH(CH3)2]3) and boric acid(17). It has been found from an ICP-MS analysis that the content of the boron in the Al2O3/B2O3 was precisely controlled. The content of the boron in the dosimeter was strongly related to thermal neutron detection efficiency. This paper describes the way of synthesising Al2O3 detectors containing isotopically enriched boron (Al2O3:10B and Al2O3:11B) using the sol-gel method. The crystalline structure of the Al2O3:B was analysed by a scanning electron microscope (SEM) and an XRD. The OSL property was investigated by an X-ray source and an OSL reader. In preliminary neutron irradiation, a thermal neutron field was constructed using an 241Am-Be neutron source and graphite blocks. The property of a pair of Al2O3:10B and Al2O3:11B detectors for thermal neutron dosimetry was investigated. MATERIAL AND METHODS Preparation of Al2O3:B The Al2O3 materials containing Al2O3:B were synthesised using the sol-gel method. The synthesis of the Al2O3:B was based on a previous report(17). Briefly, aluminium isopropoxide, boron trioxide and succinic acid were used as precursors, while nitric acid was applied to control the rates of hydrolysis and condensation. The succinic acid was used as an organic source of carbon. Isotopically enriched boron trioxides 10B2O3, 11B2O3 and natB2O3 (10B:11B = 19.9:80.1) were purchased from Cambridge Isotope Laboratories, Inc. (Tewksbury, MA, USA). The reaction was performed in a glass reactor upon stirring under temperature control. The aluminium isopropoxide was hydrolysed in water at 358 K. After 0.5 h of stirring, the resulting slurry was peptised with nitric acid. The resulting slurry was divided into several beakers. The different isotopically enriched boron trioxides were added into the resulting slurries, and the mixtures were refluxed upon stirring for 2 h. The molar ratio among the aluminium isopropoxide, the boron trioxide, the water, the succinic acid and the nitric acid was 1:0.05:200:0.01:0.1. In addition, an alumina sample without boron trioxide (Al2O3) was prepared. The resulting products were deliberately dried in a drying furnace at 363 K for 96 h to obtain xerogels. The xerogels were annealed at 773 K for 1 h to obtain Al2O3:B. Carbon powders were added to the Al2O3:B. The mixtures were placed in alumina crucibles and heated in a vacuum under 1 Pa. Its temperature was gradually increased to 1800 K over the course of 0.5 h. The samples were maintained at this temperature for 0.5 h. The samples were cooled down to room temperature in 0.2 h. The vacuum atmosphere and the rapid cooling induced oxygen vacancies in the samples(18). Throughout this process, some parts of the samples were removed for SEM and XRD analyses. SEM ANALYSIS The surface morphologies of the xerogels were observed using a SEM (JSM-5600LV, JEOL, Japan), which was operated at 15 kV. Prior to the SEM observations, thin gold layers were deposited on the samples with a radio frequency sputtering apparatus. X-RAY DIFFRACTION ANALYSIS The samples were pulverised into micro-sized particles by a mortar. The X-ray powder diffraction patterns of the particles were obtained using X-ray diffraction, XRD (X’pert Pro, Philips) with CuKα radiation at 45 kV and 40 mA. Data were collected over the 2θ range from 20 to 80° in a step size of 0.02° and a step time of 1 s. The measurement errors were within 10%. X-RAY IRRADIATION The samples were irradiated with an X-ray generator (L9421-02, Hamamatsu Photonics, Hamamatsu City, Japan). The maximum X-ray tube voltage was 90 kV and its maximum current was 89 μA. The electron beam was irradiated to the tungsten target, and its focal spot size was approximately 7 μm. The maximum absorbed dose rate for the sample was estimated to be approximately 50 mGy/s. OSL ANALYSIS The sample particles were placed on the aluminium plates and covered with polypropylene sheets 45 μm in thickness. OSL measurements with photon-counting mode were carried out using an in-house built OSL reader. The OSL reader was composed of a 532-nm green laser (CL-532–5, CrystaLaser, Reno, NV, USA), a photomultiplier tube (R9880U-01, Hamamatsu Photonics), related optics and electric components. The output power was 5 mW and the intensity on the sample surface was approximately 10 mW/cm2. The optical filters (U-340, Hoya Corporation, Milpitas, CA, USA) were set in the front of the photomultiplier tube. Its transmission band from 290 to 370 nm allowed the detection of the UV emission band and the part of the F-centre emission band centred at 420 nm(19, 20). THERMAL NEUTRON IRRADIATION A thermal neutron field was constructed using a 46-GBq 241Am-Be neutron source and graphite blocks as the neutron moderator(21). The 241Am-Be neutron source was placed at the centre of the graphite cube (100 × 100 × 100 cm3). A hole 3 cm in diameter and 50 cm in depth was made in the centre of a plane of the graphite cube. The samples were set in the hole 30 cm away from the 241Am-Be neutron source. A brass rod 30 cm in length and 2.6 cm in diameter was placed between the neutron source and the samples. The insertion of the brass rod was for a shield against gamma rays from the neutron source. After setting the samples, the hole was obstructed by a graphite rod 20 cm in length and 3 cm in diameter. The gamma rays of 60 keV were released through alpha decay of 241Am. Subsequently, fast neutrons and 4.43 MeV gamma rays were emitted in the 9Be(α,n)12C reactions(22). The fast neutrons also induced secondary gamma rays through neutron moderation. Figure 1 shows the neutron energy spectrum at the sample position, which was calculated using the Particle and Heavy Ion Transport Code System (PHITS)(23) with the Evaluated Nuclear Data File ENDF/B-VI(24). The thermal neutron flux at the sample position was measured using the activation method with gold foil and was estimated by the PHITS to be ~2 × 103 n cm−2 s−1. The absorbed dose rate for the gamma rays at the sample position was measured with a commercial glass dosimeter (GD-450, Chiyoda Technol Corporation, Tokyo, Japan) owing to its low neutron sensitivity(25) and determined to be approximately 3 nGy/s. Figure 1. Open in new tabDownload slide Neutron energy spectrum at sample position in the thermal neutron field. Figure 1. Open in new tabDownload slide Neutron energy spectrum at sample position in the thermal neutron field. RESULTS AND DISCUSSION Figure 2 shows the surface morphologies of the xerogels. The xerogel of the molar ratio of B/Al = 0.1 after drying at 363 K was transparent yellow. The uniform monoliths of B2O3/Al2O3 were confirmed. In a previous work(17), a series of binary oxide systems B2O3/Al2O3 with the B/Al molar ratios up to 1.0 were synthesised using the sol-gel technique. Uniform monoliths of B2O3/Al2O3 were obtained up to a molar ratio of B/Al = 0.3. At the molar ratios of B/Al > 0.3, the formation of B2O3 crystalline appeared outside the gel structure. The concentration of the 10B was related to the neutron sensitivity of the dosimeter. However, at the molar ratios of B/Al > 0.1, the thermal neutron detection was degraded owing to the short of the mean free path of thermal neutrons. Figure 3 shows XRD patterns for the samples. At 773 K, some broad peaks in the diffraction pattern indicated low crystallinity. The reflex could be assigned to the phase of γ-Al2O3 reported in the International Centre for Diffraction Data (ICDD) database (JCPDS 10–0425). On the other hand, the diffraction pattern of the Al2O3:B (B/Al = 0.1) at ~1800 K had sharp peaks. The reflexes were similar to the pattern of α-Al2O3 (JCPDS 10-0173). It is well known that vacancies in an α-Al2O3 dosimeter play important roles for OSL response(8). The most dominant luminescence centres, F and F+ centres, are oxygen vacancies with electrons. Therefore, the OSL response of the Al2O3:B at 773 K was hardly observed owing to the γ-Al2O3. Figure 2. Open in new tabDownload slide SEM images of xerogels synthesised using the sol-gel method. Figure 2. Open in new tabDownload slide SEM images of xerogels synthesised using the sol-gel method. Figure 3. Open in new tabDownload slide XRD patterns for synthesised Al2O3 and Al2O3:B. Figure 3. Open in new tabDownload slide XRD patterns for synthesised Al2O3 and Al2O3:B. Figure 4 shows OSL decay curves of the synthesised Al2O3:B and a commercial Al2O3:C dosimeter (Luxel badge, Landauer, Glenwood, IL, USA) after X-ray irradiation. The photon sensitivity of the Al2O3:B was approximately 2% of that of the commercial Al2O3:C. The OSL response of the commercial Al2O3:C had 2 (fast and slow) decay components originating from two different trap levels. The OSL response of the Al2O3:B had only a fast decay component(18). It is known that the minimum detectable dose of the commercial Al2O3:C is less than 10 μGy(9), although it strongly depends on the OSL readout technique. Therefore, the minimum detectable dose of the Al2O3:B was approximately 0.5 mGy. Then, further consideration of the synthesising Al2O3:B is necessary for the improvement of the photon sensitivity. Figure 5 shows the relationship between the absorbed dose and the OSL response. Five samples exposed to the same dose of gamma rays were prepared and each OSL response value was measured. The representative value was normalised to the average of the five measurement values. The coefficient of variation was defined as the standard deviation divided by the average. It was confirmed that the OSL response had satisfactory linearity for doses up to 10 Gy. The OSL efficiency of the Al2O3:B was approximately 70% of that of the synthesised Al2O3 without boron. Figure 4. Open in new tabDownload slide OSL responses of an Al2O3:B and a commercial Al2O3:C. Figure 4. Open in new tabDownload slide OSL responses of an Al2O3:B and a commercial Al2O3:C. Figure 5. Open in new tabDownload slide Relationship between the absorbed dose and the OSL response for X-ray irradiation. Figure 5. Open in new tabDownload slide Relationship between the absorbed dose and the OSL response for X-ray irradiation. Figure 6 shows the responses of an Al2O3:B sample to photons calculated using the PHITS code. The densities of the samples were 4.0 g/cm3. A sample of 10 × 10 × 0.5 mm3 was set in a sample holder with a 0.5-mm aluminium foil and a 1-mm polyethylene plate. The incident angle of the photon was perpendicular to the plane of the sample holder. The response was normalised to the value at 662 keV (137Cs gamma ray). The responses to low-energy photons for the Al2O3:B were a little smaller than that of the Al2O3, because the effective atomic number of the Al2O3:B was a little smaller than that of the Al2O3. Figure 6. Open in new tabDownload slide Photon energy responses of Al2O3 and Al2O3:B detectors. Figure 6. Open in new tabDownload slide Photon energy responses of Al2O3 and Al2O3:B detectors. Figure 7 shows the neutron kerma factors for the OSL materials, which were estimated using the PHITS. The neutron response of each detector was evaluated by integrating the neutron energy spectrum weighted by the kerma factors. The kerma factors for Al2O3:10B were extremely large in the thermal neutron region owing to 10B(n,α)7Li reactions (Q value; 2.79 or 2.31 MeV). Therefore, a pair of Al2O3:10B and Al2O3:11B detectors was extremely effective for neutrons below 10 keV. There was no large difference among the kerma factors above 100 keV. It was difficult to estimate the dose for fast neutrons. For the neutron energy spectrum as shown in figure 1, the neutron responses for fast neutrons accounted for a small percentage of the total. Figure 7. Open in new tabDownload slide Neutron kerma factors for Al2O3:10B, Al2O3:natB, Al2O3:11B and Al2O3. Figure 7. Open in new tabDownload slide Neutron kerma factors for Al2O3:10B, Al2O3:natB, Al2O3:11B and Al2O3. Figure 8 shows the responses to thermal neutrons for samples Al2O3:10B, Al2O3:natB, Al2O3:11B and synthesised Al2O3. The samples were set at the same position in the thermal neutron field. The fast and thermal neutron fluences were found to be 5 × 107 and 8 × 108 n/cm2, respectively. Each OSL readout value was measured under the same condition. The OSL responses were evidently related to the contents of 10B in the materials. A large part of the response of the Al2O3:10B mainly originated from the 10B(n,α)7Li reactions of the thermal neutrons. Meanwhile, the responses of Al2O3:11B and Al2O3 were caused mainly by gamma rays (1.4 mGy). Therefore, the difference in the responses between the Al2O3:10B and the Al2O3:11B provided the thermal neutron dose. The sensitivity to thermal neutrons was determined from the difference divided by the neutron-absorbed dose estimated from the data as shown in Figures 1 and 7. The thermal neutron sensitivity based on the 10B(n,α)7Li reactions was approximately 2% of the photon sensitivity at the same absorbed dose owing to the linear energy transfer dependence of Al2O3:C(26). Figure 8. Open in new tabDownload slide OSL responses for thermal neutron irradiations. Figure 8. Open in new tabDownload slide OSL responses for thermal neutron irradiations. CONCLUSIONS For neutron dosimetry, new OSL alumina material containing isotopically enriched boron was successfully prepared using the sol-gel method. Xerogel of binary oxide system Al2O3:B (the molar ratio of B/Al = 0.1) was synthesised from reagents of aluminium isopropoxide, isotopically enriched boron trioxide and succinic acid. The xerogel of the Al2O3:B was deliberately dried at 363 K and then annealed up to ~1800 K. For an XRD analysis, the diffraction pattern of the Al2O3:B had reflex peaks corresponding to α-Al2O3. The photon sensitivity of Al2O3:B was 2% of that of a commercial Al2O3:C. The OSL response of the Al2O3:B had only a fast decay component. The OSL response of the commercial Al2O3:C had fast and slow decay components. The Al2O3:B detector had satisfactory linearity up to 10 Gy in X-ray dose measurement. A thermal neutron field was constructed using a 241Am-Be neutron source and graphite blocks as the neutron moderator. Detectors of Al2O3:10B, Al2O3:natB, Al2O3:11B and Al2O3 were set in the thermal neutron field. The OSL responses were evidently related to the contents of 10B in the materials. It was confirmed that the thermal neutrons were detected by the difference in the responses between the Al2O3:10B and the Al2O3:11B. The sensitivity of the Al2O3:10B to thermal neutrons, which was based on the 10B(n,α)7Li reactions, was estimated by the neutron kerma factors and was two orders less than the photon sensitivity. Therefore, a pair of Al2O3:10B and Al2O3:11B detectors was useful for thermal neutron dosimetry. FUNDING This study was supported in part by a JSPS KAKENHI grant number JP16K09016. ACKNOWLEDGEMENT The authors are extremely grateful to our colleagues Masaaki Ohse and Misaki Kasakawa of Osaka University for their valuable suggestions in the XRD analysis of the alumina containing boron. REFERENCES 1 d’Errico , F. and Bos , A. J. J. Passive detectors for neutron personal dosimetry: state of the art . Radiat. Prot. Dosim. 110 ( 1–4 ), 195 – 200 ( 2004 ). Google Scholar Crossref Search ADS WorldCat 2 Atanackovic , J. , Matysiak , W., Witharana , S. S. H, Aslam , I., Dubeau , J. and Waker , A. J. Neutron spectrometry and dosimetry study at two research nuclear reactors using Bonner sphere spectrometer (BSS), rotational spectrometer (ROSPEC) and cylindrical nested neutron spectrometer (NNS) . Radiat. Prot. Dosim. 154 ( 3 ), 364 – 374 ( 2013 ). Google Scholar Crossref Search ADS WorldCat 3 Darvish-Molla , S. , Prestwich , W. V. and Byun , S. H. Comprehensive radiation dose measurements and Monte Carlo simulation for the 7Li(p,n) accelerator neutron field . Radiat. Prot. Dosim. 171 ( 4 ), 421 – 430 ( 2016 ). OpenURL Placeholder Text WorldCat 4 Takada , K. , Kumada , H., Isobe , T., Terunuma , T., Kamizawa , S., Sakurai , H., Sakae , T. and Matsumura , A. Whole-body dose evaluation with an adaptive treatment planning system for boron neutron capture therapy . Radiat. Prot. Dosim. 167 ( 4 ), 584 – 590 ( 2015 ). Google Scholar Crossref Search ADS WorldCat 5 Milenkovic , B. , Stevanovic , N., Krstic , D. and Nikezic , D. Neutron detection by a CR-39 detector and analysis of proton tracks etched in the same and opposite directions . Radiat. Prot. Dosim. 161 ( 1–4 ), 108 – 111 ( 2014 ). Google Scholar Crossref Search ADS WorldCat 6 Hajek , M. and Cruz Suárez , R. A solution for neutron personal dosimetry in the absence of workplace spectrometry . Radiat. Prot. Dosim. 170 ( 1–4 ), 265 – 268 ( 2016 ). Google Scholar Crossref Search ADS WorldCat 7 Piesch , E. and Burgkhardt , B. Albedo neutron dosimetry . Radiat. Prot. Dosim 10 ( 1–4 ), 175 – 188 ( 1985 ). Google Scholar Crossref Search ADS WorldCat 8 Akselrod , M. S. , Lucas , A. C., Polf , J. C. and McKeever , S. W. S. Optically stimulated luminescence of Al2O3 . Radiat. Meas. 29 ( 3–4 ), 391 – 399 ( 1998 ). Google Scholar Crossref Search ADS WorldCat 9 Akselrod , M. S. and McKeever , S. W. S. A radiation dosimetry method using pulsed optically stimulated luminescence . Radiat. Prot. Dosim. 81 ( 3 ), 167 – 175 ( 1999 ). Google Scholar Crossref Search ADS WorldCat 10 Sommer , M. and Henniger , J. Investigation of a BeO-based optically stimulated luminescence dosemeter . Radiat. Prot. Dosim. 119 ( 1–4 ), 394 – 397 ( 2006 ). Google Scholar Crossref Search ADS WorldCat 11 Haninger , T. , Hödlmoser , H., Figel , M., König-Meier , D., Henniger , J., Sommer , M., Jahn , A., Ledtermann , G. and Eßer , R. Properties of the BeOSL dosimetry system in the framework of a large-scale personal monitoring service . Radiat. Prot. Dosim. 170 ( 1–4 ), 269 – 273 ( 2016 ). Google Scholar Crossref Search ADS WorldCat 12 Kobayashi , H. , Satoh , M., Kobayashi , I. and Morishima , H. Neutron imaging using an optically stimulated luminescence material: α-Al2O3: C + Gd2O3 . IEEE. Trans. Nucl. Sci. 52 ( 1 ), 360 – 363 ( 2005 ). Google Scholar Crossref Search ADS WorldCat 13 Yukihara , E.G. , Mittani , J. C., Vanhavere , F. and Akselrod , M. S. Development of new optically stimulated luminescence (OSL) neutron dosimeters . Radiat. Meas. 43 ( 2–6 ), 309 – 314 ( 2008 ). Google Scholar Crossref Search ADS WorldCat 14 Passmore , C. and Kirr , M. Neutron response characterisation of an OSL neutron dosemeter . Radiat. Prot. Dosim. 144 ( 1–4 ), 155 – 160 ( 2011 ). Google Scholar Crossref Search ADS WorldCat 15 Yoldas , B.E. Alumina gels that form porous transparent Al2O3 . J. Mater. Sci. 10 , 1856 – 1860 ( 1975 ). Google Scholar Crossref Search ADS WorldCat 16 Kingsley , J.J. and Patil , K.C. A novel combustion process for the synthesis of fine particle α-alumina and related oxide materials . Mater. Letters 6 ( 11–12 ), 427 – 432 ( 1988 ). Google Scholar Crossref Search ADS WorldCat 17 Przekop , R. and Kirszensztejn , P. Porous xerogel systems B2O3-Al2O3 obtained by the sol-gel method . J. Non-Cryst. Solids 402 , 128 – 134 ( 2014 ). Google Scholar Crossref Search ADS WorldCat 18 Kulkarni , M. S. , Mishra , D. R., Muthe , K.P., Singh , A., Roy , M., Gupta , S. K. and Kannan , S. An alternative method of preparation of dosimetric grade α-Al2O3:C by vacuum-assisted post-growth thermal impurification technique . Radiat. Meas. 39 ( 3 ), 277 – 282 ( 2005 ). Google Scholar Crossref Search ADS WorldCat 19 Yukihara , E.G. and McKeever , S.W.S. Ionisation density dependence of the optically and thermally stimulated luminescence from Al2O3:C . Radiat. Prot. Dosim. 119 , 206 – 217 ( 2006 ). Google Scholar Crossref Search ADS WorldCat 20 Yukihara , E.G. and McKeever , S.W.S. Spectroscopy and optically stimulated luminescence of Al2O3:C using time-resolved measurements . J. Appl. Phys. 100 , 083512 ( 2006 ). Google Scholar Crossref Search ADS WorldCat 21 Maki , D. , Kobayashi , H., Sato , F., Murata , I., Kato , Y., Tanaka , T., Yamamoto , T. and Iida , T. Development of thermal neutron-sensitive glass dosemeter containing lithium . Radiat. Prot. Dosim. 144 ( 1–4 ), 226 – 230 ( 2011 ). Google Scholar Crossref Search ADS WorldCat 22 International Organization for Standardization . Reference Neutron Radiations—Part1: Characteristics and Methods of Production. International Standard ISO 8529–1. ISO ( 2001 ). 23 Sato , T. et al. . Particle and heavy ion transport code system PHITS, version 2.52 . J. Nucl. Sci. Technol. 50 ( 9 ), 913 – 923 ( 2013 ). Google Scholar Crossref Search ADS WorldCat 24 CSEWG-Collaboration, Evaluated Nuclear Data File ENDF/B-VI.8. Available from: http://www.nndc.bnl.gov/endf/. 25 Miljanić , S. , Ranogajec-Komor , M., Blagus , S., Pálfalvi , J. K., Pázmándi , T., Deme , S. and Szántó , P. Response of radiophotoluminescent dosimeters to neutrons . Radiat. Meas. 43 ( 2 ), 1068 – 1071 ( 2008 ). Google Scholar Crossref Search ADS WorldCat 26 Granville , D.A. , Sahoo , N. and Sawakuchi , G.O. Linear energy transfer dependence of Al2O3:C optically stimulated luminescence detectors exposed to therapeutic proton beams . Radiat. Meas. 71 , 69 – 73 ( 2014 ). Google Scholar Crossref Search ADS WorldCat © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com
TI - DEVELOPMENT OF ISOTOPICALLY ENRICHED BORON-DOPED ALUMINA DOSIMETER FOR THERMAL NEUTRONS
JF - Radiation Protection Dosimetry
DO - 10.1093/rpd/ncx066
DA - 2017-12-01
UR - https://www.deepdyve.com/lp/oxford-university-press/development-of-isotopically-enriched-boron-doped-alumina-dosimeter-for-2AJIrPgjIE
SP - 475
VL - 177
IS - 4
DP - DeepDyve
ER -