Mohammad Nakhostin

Dr Mohammad Nakhostin


Research Officer (Experimental Nuclear Physicist)
+44 (0)1483 686113
13 BC 03

Academic and research departments

Department of Physics.

My publications

Publications

Ishikawa M, Itoga T, Okuji T, Nakhostin M, Shinohara K, Hayashi T, Sukegawa A, Baba M, Nishitani T (2006) Fast collimated neutron flux measurement using stilbene scintillator and flashy analog-to-digital converter in JT-60U, REVIEW OF SCIENTIFIC INSTRUMENTS 77 (10) AMER INST PHYSICS
Nakhostin M, Ishii K, Yamazaki H, Matsuyama S, Kikuchi Y (2009) Development of two-dimensional position sensitive CdTe detector for next generation PET scanners, J Nucl Med. 2009; 50 (Supplement 2):1538
Nakhostin M, Walker PM (2010) Determination of gas amplification factor by digital waveform analysis of avalanche counter signals,NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT 615 (1) pp. 53-56 ELSEVIER SCIENCE BV
Chaudhuri SK, Lohstroh A, Nakhostin M, Sellin PJ (2012) Digital pulse height correction in HgI 2 ³-ray detectors, Journal of Instrumentation 7 (4) T04002 Elsevier
We report on the application of digital pulse processing algorithms to improve the
spectroscopic performance of a 1.2 mm thick planar HgI2 g-ray detector. We have used offline
processing of pulses which were recorded using a high resolution waveform digitizer. The recovery
processes include long duration shaping to avoid ballistic deficit in the case of slow pulses, and
the application of biparametric correction techniques to compensate for charge loss. Pulses of
duration as long as 100 ms were recorded to facilitate long duration shaping. Two different pulse
processing algorithms, viz. semi-Gaussian and moving window deconvolution, were applied and
their performance was compared. The application of long duration shaping and digital chargeloss
correction improved the energy resolution at 662 keV by more than 20% and the peak to
background ratio by a factor of two. The resolution and the peak to background ratio were further
seen to improve drastically upon rejection of counts with very slow rise-time. A 2.6% energy
resolution at 662 keV with 14:1 peak to background ratio was obtained.
Mason PJR, Alharbi T, Regan PH, Marginean N, Podolyak Z, Simpson EC, Alkhomashi N, Bender PC, Bowry M, Bostan M, Bucurescu D, Bruce AM, Cata-Danil G, Cata-Danil I, Chakrabarti R, Deleanu D, Detistov P, Erduran MN, Filipescu D, Garg U, Glodariu T, Ghita D, Ghugre SS, Kusoglu A, Marginean R, Mihai C, Nakhostin M, Negret A, Pascu S, Triguero CR, Sava T, Sinha AK, Stroe L, Suliman G, Zamfir NV (2012) Half-life of the I-pi=4(-) intruder state in P-34: M2 transition strengths approaching the island of inversion,PHYSICAL REVIEW C 85 (6) ARTN 064303 AMER PHYSICAL SOC
Nakhostin M, Baba M, Itoga T, Oishi T, Unno Y, Kamada S, Okuji T (2008) A fast response and gamma-insensitive neutron detector based on parallel-plate avalanche counter., Radiat Prot Dosimetry 129 (4) pp. 426-430
The use of the parallel-plate avalanche counter for slow-neutron counting is described. The choice of a suitable neutron converter is discussed on the basis of Monte Carlo simulation, and some experimental results are shown. Excellent gamma-insensitivity, high rate capability, possibility of construction in large sensitive area and low production cost are among the promising features of this neutron detector.
Hitomi K, Kikuchi Y, Nakhostin M, Shoji T, Ishii K (2009) Fabrication of TlBr strip detectors, Proceedings of SPIE - The International Society for Optical Engineering 7449
TlBr strip detectors with four anode strip electrodes were fabricated in this study. The strip electrodes were formed on TlBr wafers 1 mm thick with a vacuum evaporation process through a shadow mask. Each strip had a width of 0.8 mm and a length of 3.5 mm approximately. The gap between the strips was approximately 0.1 mm. Inter strip resistance more than 1 G© was obtained with the process. Energy resolutions of 7.0% and 3.8% FWHM were recorded for 511 keV and 1.33 MeV gamma-rays, respectively, with the TlBr strip detector at room temperature.
Nakhostin M, Kikuchi Y, Ishii K, Matsuyama S, Yamazaki H (2013) Use of commercial operational amplifiers in a low cost multi-channel preamplifier system, Radiation Physics and Chemistry 85 pp. 18-22
We report on a simple, compact-size and cost-effective multi-channel charge-sensitive preamplifier system using the commercial IC operational amplifiers. An energy resolution of 5.6% at 511keV is achieved with a large size (10×10×1mm3) planar CdTe detector. The system is well suited for use with the compound semiconductor detectors in the applications in which the rather high power consumption of the system (320mW per channel) can be tolerated. © 2012 Elsevier Ltd.
Ishii K, Hitomi K, Nakhostin M, Kikuch Y, Fujiwara M, Yamazaki H, Matsuyama S, Terakawa A (2008) Prototype of TlBr Detector Array for Ultra High Resolution PET, Nuclear Science Symposium Conference Record pp. 2984-2985 IEEE
We developed a prototype of TlBr semiconductor detector array for high resolution PET scanner with less than 1mm FWHM. We obtained an energy resolution of similar to 20% FWHM for 511 keV and a coincidence time resolution of similar to 50nsec FWHM at a detector bias 100V. This result expects the capability of application of TlBr detector array to a high resolution PET scanner. The TlBr detector arrays with the present time resolution performance can be applied to a small PET scanner for the PET study using small animals such as rats and mice.
Itoga T, Ishikawa M, Baba M, Okuji T, Oishi T, Nakhostin M, Nishitani T (2007) Fast response neutron emission monitor for fusion reactor using stilbene scintillator and Flash-ADC., Radiat Prot Dosimetry 126 (1-4) pp. 380-383
The stilbene neutron detector which has been used for neutron emission profile monitoring in JT-60U has been improved, to respond to the requirement to observe the high-frequency phenomena in megahertz region such as toroidicity-induced Alfvén Eigen mode in burning plasma as well as the spatial profile and the energy spectrum. This high-frequency phenomenon is of great interest and one of the key issues in plasma physics in recent years. To achieve a fast response in the stilbene detector, a Flash-ADC is applied and the wave form of the anode signal stored directly, and neutron/gamma discrimination was carried out via software with a new scheme for data acquisition mode to extend the count rate limit to MHz region from 1.3 x 10(5) neutron/s in the past, and confirmed the adequacy of the method.
Nakhostin M, Ishii K, Kikuchi Y, Matsuyama S, Yamazaki H, Torshabi AE (2009) Time resolution improvement of Schottky CdTe PET detectors using digital signal processing, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT 606 (3) pp. 681-688 ELSEVIER SCIENCE BV
Baba M, Takahashi W, Oishi T, Nakhostin M, Ohtsuki T, Yuki H, Hori J, Nakajima K (2006) Measurement of neutron-induced fission cross section of actinide elements using lead-slowing down spectrometer (III), KURRI Progress Report
Nakhostin M, Podolyak Z, Regan PH, Walker PM (2010) A digital method for separation and reconstruction of pile-up events in germanium detectors,REVIEW OF SCIENTIFIC INSTRUMENTS 81 (10) ARTN 103507 AMER INST PHYSICS
Kempley RS, Podolyak Z, Bazzacco D, Gadea A, Farnea E, Valiente-Dobon JJ, Mengoni D, Recchia F, Sahin E, Gottardo A, Corradi L, Fioretto E, Szilner S, Anagnostatou V, Al-Dahan N, De Angelis G, Bellato M, Berti B, Bortolato D, Bowry M, Bunce M, Cocconi P, Colombo A, Dombradi Z, Fanin C, Gelletly W, Isocrate R, Ketenci S, Kondratyev N, Kuti I, Mason PJR, Michelagnoli C, Mijatovic T, Molini P, Montagnioli G, Montanari D, Nakhostin M, Napoli DR, Pellegrini D, Regan PH, Rampazzo G, Reiter P, Rosso D, Scarlassara F, Stefanini A, Singh P, Toniolo N, Ur CA (2011) CROSS-COINCIDENCES IN THE Xe-136+Pb-208 DEEP-INELASTIC REACTION,ACTA PHYSICA POLONICA B 42 (3-4) pp. 717-720 WYDAWNICTWO UNIWERSYTETU JAGIELLONSKIEGO
Alharbi T, Mason PJR, Regan PH, Podolyák Z, Mârginean N, Nakhostin M, Bowry M, Bucurescu D, Câta-Danil G, Câta-Danil I, Deleanu D, Filipescu D, Glodariu T, Ghicâ D, Mârginean R, Mihai C, Negret A, Pascu S, Sava T, Stroe L, Suliman G, Zamfir NV, Bruce AM, Rodriguez Triguero C, Bender PC, Garg U, Erduran MN, Kusoglu A, Bostan M, Detistov P, Alkhomashi N, Sinha AK, Chakrabarti R, Ghugre SS (2012) Gamma-ray fast-timing coincidence measurements from the 18O+ 18O fusion-evaporation reaction using a mixed LaBr 3-HPGe array, Applied Radiation and Isotopes 70 (7) pp. 1337-1339
We report on a gamma-ray coincidence analysis using a mixed array of hyperpure germanium and cerium-doped lanthanum tri-bromide (LaBr 3:Ce) scintillation detectors to study nuclear electromagnetic transition rates in the pico-to-nanosecond time regime in 33,34P and 33S following fusion-evaporation reactions between an 18O beam and an isotopically enriched 18O implanted tantalum target. Energies from decay gamma-rays associated with the reaction residues were measured in event-by-event coincidence mode, with the measured time difference information between the pairs of gamma-rays in each event also recorded using the ultra-fast coincidence timing technique. The experiment used the good full-energy peak resolution of the LaBr 3:Ce detectors coupled with their excellent timing responses in order to determine the excited state lifetime associated with the lowest lying, cross-shell, I À=4 - "intruder" state previously reported in the N=19 isotone 34P. The extracted lifetime is consistent with a mainly single-particle M2 multipolarity associated with a f 7/2’d 5/2 single particle transition. © 2011 Elsevier Ltd.
Nakhostin M, Podolyak Z, Sellin PJ (2013) Application of pulse-shape discrimination to coplanar CdZnTe detectors, Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 729 pp. 541-545
A digital pulse-shape discrimination algorithm for the identification of multi-site ³-ray interactions in coplanar CdZnTe detectors has been developed. The algorithm is used to suppress the Compton continuum in ³-ray spectroscopy measurements by rejecting the single-site events. The results of our study with a 15×15×7.5 mm3 detector demonstrate the effectiveness of this approach for revealing low intensity ³-ray peaks in the examined energy range (511-1274 keV), which is of importance for environmental and security applications. The method is also very useful for background reduction in the neutrinoless double beta-decay experiments for which coplanar CdZnTe detectors are of interest. © 2013 Elsevier B.V.
Nakhostin M, Oishi T, Baba M (2008) Time resolution measurement of avalanche counters using digital signal processing technique, RADIATION MEASUREMENTS 43 (9-10) pp. 1493-1497 PERGAMON-ELSEVIER SCIENCE LTD
Zieblinski M, Jastrzab M, Dokania N, Nanal V, Brambilla S, Bednarczyk P, Ciemaa M, Dutkiewicz E, Kmiecik M, Krzysiek M, Lekki J, Maj A, Szklarz Z, Wasilewska B, Dudeo M, Hadynska-Klek K, Napiorkowski P, Genolini B, Schmitt C, Catford W, Nakhostin M, Yavuzkanat N, Dorvaux O, Pillay RG, Pose MS, Mishra S, Mathimalar S, Singh V, Katyan N, Chakrabarty DR, Datar VM, Kumar S, Mishra G, Mukhopadhyay S, Pandit D, Erturk S (2013) Testing of the Paris LaBr3-NaI phoswich detector with high energy gamma-rays, Acta Physica Polonica B 44 (3) pp. 651-656
We report on tests of LaBr3:Ce-NaI:Tl phoswich detectors with-rays at various ³-ray energies, up to 22.56 MeV, using radioactive sources and nuclear reactions induced by proton beams delivered by accelerators at IFJ PAN Kraków and PLF Mumbai. Two-dimensional analysis of complex waveforms recorded with digital electronics is compared to analog discrimination methods. Both approaches allow to resolve the LaBr3:Ce and NaI:Tl signal components, and to construct clean associated ³-ray spectra. A digital algorithm to be implemented for the PARIS scintillator array is investigated.
Alharbi T, Mason PJR, Regan PH, Marginean N, Podolyak Z, Algora A, Alazemi N, Bruce AM, Britton R, Bunce MR, Bucurescu D, Cooper N, Deleanu D, Filipescu D, Gelletly W, Ghita D, Glodariu T, Ilie G, Kisyov S, Lintott J, Lalkovski S, Liddick S, Mihai C, Mulholland K, Marginean R, Negret A, Nakhostin M, Roberts OJ, Rice S, Smith JF, Stroe L, Sava T, Townsley C, Wilson E, Werner V, Zhekova M, Zamfir NV (2012) Electromagnetic Transition Rate Measurements in the N=80 Isotone, Ce-138, RUTHERFORD CENTENNIAL CONFERENCE ON NUCLEAR PHYSICS, 2011 381 IOP PUBLISHING LTD
Nakhostin M, Walker PM (2010) Application of digital zero-crossing technique for neutron-gamma discrimination in liquid organic scintillation detectors,NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT 621 (1-3) pp. 498-501 ELSEVIER SCIENCE BV
Nakhostin M, Baba M, Oishi T, Itoga T, Unno Y, Kamata S, Otsuki T (2007) A new fast response, gamma-insensitive neutron beam monitor for advanced pulsed Neutron sources, Proceedings of the 21st Workshop on Radiation Detectors and Their Uses pp. 175-182
Nakhostin M, Baba M, Ohtsuki T, Oshi T, Itoga T (2007) Precise measurement of first Townsend coefficient, using parallel plate avalanche chamber, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT 572 (2) pp. 999-1003 ELSEVIER SCIENCE BV
Mohammadi A, Baba M, Nakhostin M, Ohuchi H, Abe M (2012) Compton spectroscopy for rotation-mode computed tomography, JOURNAL OF X-RAY SCIENCE AND TECHNOLOGY 20 (2) pp. 131-140 IOS PRESS
Ishikawa M, Itoga T, Okuji T, Nakhostin M, Shinohara K, Baba M, Nishitani T (2008) Development of fast measurement system of neutron emission profile using a digital signal processing technique in JT-60U, BURNING PLASMA DIAGNOSTICS 988 pp. 295-298 AMER INST PHYSICS
Mason PJR, Alharbi T, Regan PH, Marginean N, Podolyak Z, Alkhomashi N, Bender PC, Bowry M, Bostan M, Bucurescu D, Bruce AM, Cata-Danil G, Cata-Danil I, Chakrabarti R, Deleanu D, Detistov P, Erduran MN, Filipescu D, Garg U, Glodariu T, Ghita D, Ghugre SS, Kusoglu A, Marginean R, Mihai C, Nakhostin M, Negret A, Pascu S, Triguero CR, Sava T, Simpson EC, Sinha AK, Stroe L, Suliman G, Zamfir NV (2012) Half-life of the I-pi=4(-) Intruder State in P-34 Using LaBr3:Ce Fast Timing, RUTHERFORD CENTENNIAL CONFERENCE ON NUCLEAR PHYSICS, 2011 381 IOP PUBLISHING LTD
Nakhostin M, Kikuchi Y, Ishii K, Matsuyama S, Yamazaki H (2010) Development of a digital front-end electronics for the CdTe PET systems, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT 614 (2) pp. 308-312 ELSEVIER SCIENCE BV
Mason PJR, Alharbi T, Regan PH, Mrginean N, Podolyàk Z, Alkhomashi N, Bender PC, Bowry M, Bostan M, Bucurescu D, Bruce AM, Cta-Danil G, Cta-Danil I, Chakrabarti R, Deleanu D, Detistov P, Erduran MN, Filipescu D, Garg U, Glodariu T, Ghic D, Ghugre SS, Kusoglu A, Mrginean R, Mihai C, Nakhostin M, Negret A, Pascu S, Triguero CR, Sava T, Simpson EC, Sinha AK, Stroe L, Suliman G, Zamfir NV (2012) Half-life of the I À 4 - intruder state in 34P using LaBr 3:Ce fast timing, Journal of Physics: Conference Series 381 (1)
The half-life of the I À 4 - intruder state at 2305 keV in 3415P19 has been measured using ³-ray coincident fast timing with LaBr 3:Ce scintillation detectors. Excited states in 34P were populated in the 18O( 18O,pn) 34P reaction at a beam energy of 36 MeV at the Tandem Laboratory at the National Institute of Physics and Nuclear Engineering, Bucharest, Romania. A half-life of t 1/2
Nakhostin M, Baba M (2007) Comment on "On spectrometric properties of transmission avalanche counters at moderate specific ionization", NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT 578 (2) pp. 453-454 ELSEVIER SCIENCE BV
Regan PH, Podolyák Z, Alharbi T, Mason PJR, Bruce AM, Townsley C, Roberts OJ, MÎrginean N, MÎrginean R, GhitÎ D, Mullholland K, Smith JF, Britton R, Patel Z, Nakhostin M, Rice S, Wilson E, Alazemi N, Alkhomashi N, Bucurescu D, Cata-Danil G, Deleanu D, Filipescu D, Glodariu T, Cata-Danil I, Mihai C, Negret A, Nita CR, Sava T, Stroe L, Suliman G, Detistov P, Garg U, Bender PC, Algora A, Liddick S, Cooper N, Werner V, Lalkovski S, Kisyov S, Browne F, Söderström PA, Watanabe H, Sumikama T (2013) Precision lifetime measurements using LaBr3detectors with stable and radioactive beams, EPJ Web of Conferences 63
A range of high resolution gamma-ray spectroscopy measurements have been carried out using arrays which include a number of Cerium-doped Lanthanum-Tribromide (LrBr3(Ce)) scintillation detectors used in conjunction with high-resolution hyper-pure germanium detectors. Examples of the spectral and temporal responses of such set-ups, using both standard point radioactive sources 152Eu and 56Co, and in-beam fusionevaporation reaction experiments for precision measurements of nuclear excited states in 34P and 138Ce are presented. The current and future use of such arrays at existing (EURICA at RIKEN) and future (NUSTAR at FAIR) secondary radioactive beam facilities for precision measurements of excited nuclear state lifetimes in the 10 ps to 10 ns regime are also discussed. © Owned by the authors, published by EDP Sciences, 2013.
Nakhostin M, Hitomi K (2012) Digital pulse processing for planar TlBr detectors, optimized for ballistic deficit and charge-trapping effect, Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 675 pp. 47-50
The energy resolution of thallium bromide (TlBr) detectors is significantly limited by charge-trapping effect and pulse ballistic deficit, caused by the slow charge collection time. A digital pulse processing algorithm has been developed aiming to compensate for charge-trapping effect, while minimizing pulse ballistic deficit. The algorithm is examined using a 1 mm thick TlBr detector and an excellent energy resolution of 3.37% at 662 keV is achieved at room temperature. The pulse processing algorithms are presented in recursive form, suitable for real-time implementations. © 2012 Elsevier B.V. All rights reserved.
Alharbi T, Mason PJR, Regan PH, Mrginean N, Podolyák Z, Algora A, Alazemi N, Bruce AM, Britton R, Bunce MR, Bucurescu D, Cooper N, Deleanu D, Filipescu D, Gelletly W, Ghit D, Glodariu T, Ilie G, Kisyov S, Lintott J, Lalkovski S, Liddick S, Mihai C, Mulholland K, Mrginean R, Negret A, Nakhostin M, Roberts OJ, Rice S, Smith JF, Stroe L, Sava T, Townsley C, Wilson E, Werner V, Zhekova M, Zamfir NV (2012) Electromagnetic transition rate measurements in the N=80 isotone, 138Ce, Journal of Physics: Conference Series 381 (1)
A study of intrinsic state halflife measurements in the N=80 nucleus 138Ce has been made using the 130Te( 12C,4n) 138Ce fusion evaporation reaction at beam energy of 56 MeV. The fast-timing gamma-ray coincidence method was used with a mixed LaBr 3(Ce)-HPGe array to establish the lifetimes of the yrast 6 + state at 2294 keV, the I À=5 - state at 2218 keV, the I À=11 + state at 3943 keV and the 14 + state at that at 5312 keV, all of which are in the sub nanosecond regime. Reduced transition probabilities have been calculated for the electromagnetic decays from these states. © Published under licence by IOP Publishing Ltd.
Nakhostin M, Baba M (2013) A thermal neutron beam monitor based on avalanche counter, Radiation Physics and Chemistry 86 pp. 64-67
© 2013 Elsevier Ltd.A simple neutron beam monitor based on the combination of a low-pressure position-sensitive avalanche counter with a 6Li neutron converter has been developed. The details of the construction of the device, as well as, the results of the test of the device with a thermal neutron beam are described. The main features of the neutron beam monitor are high count-rate capability, low ³-sensitivity, low perturbation on neutron beams and a position sensitivity of ~2 mm.
Kikuchi Y, Ishii K, Yamazaki H, Matsuyama S, Nakhostin M, Sakai T, Nakamura K, Kouno M (2008) Fundamental study of two-dimensional position sensitive CdTe detector for PET camera, IEEE Nuclear Science Symposium Conference Record pp. 4924-4926
Applying downsized semiconductor detectors to PET cameras makes it possible to achieve high spatial resolutions.
Luszik-Bhadra M, Nakhostin M, Niita K, Nolte R (2008) Electronic personal neutron dosemeters for energies up to 100 MeV: Calculations using the PHITS code, RADIATION MEASUREMENTS 43 (2-6) pp. 1044-1048 PERGAMON-ELSEVIER SCIENCE LTD
Nakhostin M (2013) A new digital method for high precision neutron-gamma discrimination with liquid scintillation detectors, JOURNAL OF INSTRUMENTATION 8 ARTN P05023 IOP PUBLISHING LTD
Nakhostin M, Kikuchi Y, Ishii K, Matsuyama S, Yamazaki H (2012) Use of commercial operational amplifiers in a low cost multi-channel preamplifier system, Radiation Physics and Chemistry
We report on a simple, compact-size and cost-effective multi-channel charge-sensitive preamplifier system using the commercial IC operational amplifiers. An energy resolution of 5.6% at 511 keV is achieved with a large size (10×10×1 mm
) planar CdTe detector. The system is well suited for use with the compound semiconductor detectors in the applications in which the rather high power consumption of the system (320 mW per channel) can be tolerated. © 2012 Elsevier Ltd. All rights reserved.
Nakhostin M, Hitomi K, Ishii K, Kikuchi Y (2010) Digital pulse processing for planar TlBr detectors, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT 615 (2) pp. 242-244 ELSEVIER SCIENCE BV
Alharbi T, Regan PH, Mason PJR, MÎrginean N, Podolyák Z, Bruce AM, Simpson EC, Algora A, Alazemi N, Britton R, Bunce MR, Bucurescu D, Cooper N, Deleanu D, Filipescu D, Gelletly W, GhitÎ D, Glodariu T, Ilie G, Kisyov S, Lintott J, Lalkovski S, Liddick S, Mihai C, Mulholland K, MÎrginean R, Negret A, Nakhostin M, Nita CR, Roberts OJ, Rice S, Smith JF, Stroe L, Sava T, Townsley C, Wilson E, Werner V, Zhekova M, Zamfir NV (2013) Electromagnetic transition rates in the N=80 nucleus 58138Ce, Physical Review C - Nuclear Physics 87 (1)
The half-life of the IÀ=6+ yrast state at Ex=2294 keV in 138Ce has been measured as T1/2=880(19) ps using the fast-timing ³-ray coincidence method with a mixed LaBr3(Ce)- HPGe array. The excited states in 138Ce have been populated by the 130Te(12C,4n) fusion-evaporation reaction at an incident beam energy of 56 MeV. The extracted B(E2;61+’41+)=0.101(24) W.u. value is compared with the predictions of truncated basis shell model calculations and with the systematics of the region. This shows an anomalous behavior compared to the neighboring isotonic and isotopic chains. Half-lives for the yrast 5-, 11+ and 14+ states in 138Ce have also been determined in this work. © 2013 American Physical Society.
Nakhostin M (2012) Recursive algorithms for digital implementation of neutron/gamma discrimination in liquid scintillation detectors, Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 672 pp. 1-5
Charge-comparison and zero-crossing techniques are the two most common methods of neutron-gamma discrimination in liquid scintillation detectors in analog domain. To implement these methods on a digital hardware such as field programmable gate array (FPGA), algorithms with low computational requirements are required. This paper reports on recursive algorithms for charge-comparison and zero-crossing techniques, suitable for real-time implementation on a digital hardware. The performance of the algorithms is examined using an experimental setup as well. © 2012 Elsevier B.V. All rights reserved.
Nakhostin M, Baba M, Oishi T (2008) Double-stage Low-pressure Parallel Plate Avalanche Counter: A High Count Rate Charged Particle Detector, JOURNAL OF NUCLEAR SCIENCE AND TECHNOLOGY pp. 379-382 TAYLOR & FRANCIS LTD
Nakhostin M (2009) Performance of a low-pressure Micromegas-like gaseous detector, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT 598 (2) pp. 496-500 ELSEVIER SCIENCE BV
Nakhostin M, Veeramani P (2012) A new method for charge-loss correction of room-temperature semiconductor detectors using digital trapezoidal pulse shaping, JOURNAL OF INSTRUMENTATION 7 ARTN P06006 IOP PUBLISHING LTD
Nakhostin M (2011) Recursive Algorithms for Real-Time Digital CR-(RC)n Pulse Shaping, IEEE Transactions on Nuclear Science 58 (5) pp. 2378-2381 IEEE
This paper reports on recursive algorithms for real-time implementation of CR-(RC)n filters in digital nuclear spectroscopy systems. The algorithms are derived by calculating the Z-transfer function of the filters for filter orders up to n=4 . The performances of the filters are compared with the performance of the conventional digital trapezoidal filter using a noise generator which separately generates pure series, 1/f and parallel noise. The results of our study enable one to select the optimum digital filter for different noise and rate conditions.
Nakhostin M, Baba M, Oishi T, Itoga T, Hagiwara M (2007) An ultra fast, radiation-resistant fast neutron detector., Radiat Prot Dosimetry 126 (1-4) pp. 190-193
This paper describes a study on 14-MeV neutron detection based on the combination of a parallel plate avalanche chamber with a sheet of polypropylene as fast neutron-to-charged-particle converter. By employing a carefully shielded chamber, neutron-induced charged particles background from the chamber body was successfully reduced to
Alharbi T, Mason PJ, Regan PH, Podolyák Z, M?rginean N, Nakhostin M, Bowry M, Bucurescu D, C?ta-Danil G, C?ta-Danil I, Deleanu D, Filipescu D, Glodariu T, Ghic? D, M?rginean R, Mihai C, Negret A, Pascu S, Sava T, Stroe L, Suliman G, Zamfir NV, Bruce AM, Rodriguez Triguero C, Bender PC, Garg U, Erduran MN, Kusoglu A, Bostan M, Detistov P, Alkhomashi N, Sinha AK, Chakrabarti R, Ghugre SS (2012) Gamma-ray fast-timing coincidence measurements from the (18)O+(18)O fusion-evaporation reaction using a mixed LaBr(3)-HPGe array,Appl Radiat Isot 70 (7) pp. 1337-1339 Elsevier
We report on a gamma-ray coincidence analysis using a mixed array of hyperpure germanium and cerium-doped lanthanum tri-bromide (LaBr(3):Ce) scintillation detectors to study nuclear electromagnetic transition rates in the pico-to-nanosecond time regime in (33,34)P and (33)S following fusion-evaporation reactions between an (18)O beam and an isotopically enriched (18)O implanted tantalum target. Energies from decay gamma-rays associated with the reaction residues were measured in event-by-event coincidence mode, with the measured time difference information between the pairs of gamma-rays in each event also recorded using the ultra-fast coincidence timing technique. The experiment used the good full-energy peak resolution of the LaBr(3):Ce detectors coupled with their excellent timing responses in order to determine the excited state lifetime associated with the lowest lying, cross-shell, I(À)=4(-) "intruder" state previously reported in the N=19 isotone (34)P. The extracted lifetime is consistent with a mainly single-particle M2 multipolarity associated with a f(7/2)’d(5/2) single particle transition.
Nakhostin M, Walker PM, Sellin PJ (2010) Time walk correction of CdTe detectors using depth sensing technique,Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 621 (1-3) pp. 506-512 Elsevier
A digital timing method aiming to minimize the time walk caused by the depth-dependent pulse shape variations in CdTe detectors has been developed. Detector pulses are digitized at the preamplifier stage and a full digital process is carried out to deduce and correct the time walk according to the interaction depth. A time resolution of 6.52 ns FWHM at an energy threshold of 150 keV with a CdTe detector (10×10×1 mm3) is achieved, which is close to the intrinsic resolution of the detector. The method improves the time resolution with no loss of detection efficiency and it is easy to implement. It is confirmed that the slow mobility and the short lifetime of the holes are major obstacles for further improvement in the timing performance of the CdTe detectors. The method is applicable to any semiconductor detector.
Nakhostin Mohammad (2017) Optimizing timing performance of CdTe detectors for PET,Physics in Medicine and Biology 62 (19) pp. N485-N505 IOP Publishing
Despite several attractive properties, the poor timing performance of compound semiconductor detectors such as CdTe and CdZnTe has hindered their use in commercial PET imaging systems. The standard method of pulse timing with such detectors is to employ a constant-fraction discriminator (CFD) at the output of a timing filter which is fed by the pulses from a charge-sensitive preamplifier. The method has led to a time resolution of about 10 ns at full-width at half-maximum (FWHM) with 1 mm thick CdTe detectors. This paper presents a detailed investigation on the parameters limiting the timing performance of Ohmic contact planar CdTe detectors with the standard pulse timing method. The jitter and time-walk errors are studied through simulation and experimental measurements and it is revealed that the best timing results obtained with the standard timing method suffer from a significant loss of coincidence events (~50 %). In order to improve the performance of the detectors with full detection efficiency, a new digital pulse timing method based on a simple pattern recognition technique was developed. A time resolution of 3.29±0.10 ns (FWHM) in the energy range of 300-650 keV was achieved with an Ohmic contact planar CdTe detector (5×5×1 mm3). The digital pulse processing method was also used to correct for the charge-trapping effect and an improvement in the energy resolution from 4.83±0.66 % to 2.780±0.002 % (FWHM) at 511 keV was achieved. Further improvement of time resolution through a moderate cooling of the detector and the application of the method to other detector structures are also discussed.
Nakhostin M (2015) A comparison of digital zero-crossing and charge-comparison methods
for neutron/³-ray discrimination with liquid scintillation detectors
,
Nuclear Instruments and Methods in Physics Research A 797 pp. 77-82 Elsevier
In this paper,we have compared the performances of the digital zero-crossing and charge-comparison
methods forn/³ discrimination with liquid scintillation detectors at low light outputs. The measurements were performed with a 23 x 23 cylindrical liquid scintillation detector of type BC501A whose
outputs were sampled by means of a fast wave form digitizer with 10-bit resolution,4G S/s sampling rate
and one volt input range. Different light output ranges were measured by operating the photomultiplier
tube at different voltages and a new recursive algorithm was developed to implement the digital zero-
crossing method.The results of our study demonstrate the superior performance of the digital zero-
crossing method at low light outputs when a large dynamic range is measured.However,when the input
range of the digitizer is used to measure a narrow range of light outputs, the charge-comparison method
slightly outperforms the zero-crossing method. The
results are discussed in regard to the effects of the
quantization noise and the noise filtration performance of the zero-crossing filter.
slightly outperforms the zero-crossing method. The results are discussed in regard to the effects of the
quantization noise and the noise filtration performance of the zero-crossing filter.
Nakhostin Mohammad (2013) Charged particle response of transmission diamond detectors,Nuclear Instruments and Methods in Physics Research A 703 pp. 199-203 Elsevier
A theoretical description of the shape of pulses initiated by charged particles in the transmission
diamond detectors is presented. The calculated pulse-shapes are used to investigate the effects of
parameters such as detector?s geometry,operating voltage and carriers? lifetimes on the performance of
the detectors.
This book provides a clear understanding of the principles of signal processing of radiation detectors. It puts great emphasis on the characteristics of pulses from various types of detectors and offers a full overview on the basic concepts required to understand detector signal processing systems and pulse processing techniques. Signal Processing for Radiation Detectors covers all of the important aspects of signal processing, including energy spectroscopy, timing measurements, position-sensing, pulse-shape discrimination, and radiation intensity measurement.

The book encompasses a wide range of applications so that readers from different disciplines can benefit from all of the information. In addition, this resource:
Describes both analog and digital techniques of signal processing
Presents a complete compilation of digital pulse processing algorithms
Extrapolates content from more than 700 references covering classic papers as well as those of today
Demonstrates concepts with more than 340 original illustrations
Signal Processing for Radiation Detectors provides researchers, engineers, and graduate students working in disciplines such as nuclear physics and engineering, environmental and biomedical engineering, and medical physics and radiological science, the knowledge to design their own systems, optimize available systems or to set up new experiments.

Nakhostin Mohammad, Hitomi K (2018) Pulse-height loss in the signal readout circuit of compound semiconductor
detectors
,
Nuclear Instruments and Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 893 pp. 146-150 Elsevier
Compound semiconductor detectors such as CdTe, CdZnTe, HgI2 and TlBr are known to exhibit large variations
in their charge collection times. This paper considers the effect of such variations on the measurement of induced
charge pulses by using resistive feedback charge-sensitive preamplifiers. It is shown that, due to the finite decaytime
constant of the preamplifiers, the capacitive decay during the signal readout leads to a variable deficit in
the measurement of ballistic signals and a digital pulse processing method is employed to correct for it. The
method is experimentally examined by using sampled pulses from a TlBr detector coupled to a charge-sensitive
preamplifier with 150 ¼s of decay-time constant and 20 % improvement in the energy resolution of the detector
at 662 keV is achieved. The implications of the capacitive decay on the correction of charge-trapping effect by
using depth-sensing technique are also considered.
Nakhostin Mohammad (2018) Digital Pulse Timing with Semiconductor Gamma-ray Detectors Using a Wavelet Transform Technique,Review of Scientific Instruments AIP Publishing
Obtaining precise timing information from semiconductor gamma-ray detectors is of great interest for a variety of applications such as high-resolution positron emission tomography (PET). However, pulse timing with these detectors through the common constant-fraction discrimination (CFD) method is strongly affected by the time-walk error that results from the inherent variations in the shape of the detectors? pulses. This paper reports on the use of the wavelet transform for minimizing the time-walk error in digital CFD pulse timing with semiconductor gamma-ray detectors. The details of the method are described and the experimental results with a 1 mm thick CdTe detector are shown. It is demonstrated that, by using the Haar wavelet transform of the digitized preamplifier pulses, the original tailed time spectrum of the detector with a time resolution of 8.22±0.12 ns at full-width at half-maximum (FWHM) in the energy range of 300-550 keV improves to a symmetric time spectrum with a time resolution of 3.39±0.02 ns (FWHM).
Nakhostin M. (2019) Digital discrimination of neutrons and ³-rays in liquid scintillation detectors by using low sampling frequency ADCs,Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 916 pp. 66-70 Elsevier
It is well known that the digital pulse-shape discrimination (PSD) of fast neutrons and ³-rays in liquid scintillation detectors can be adversely affected by the low sampling frequency of the analog-to-digital converter (ADC). Previous studies have recommended that using an ADC with a sampling frequency of above 250 MHz is necessary to achieve a PSD performance comparable to that of the analog PSD systems. In the present study, we show that, in principle, a sampling frequency of above 32 MHz is sufficient to fully preserve the pulse-shape information of liquid scintillation detectors, though at such sampling frequencies a significant degradation of the PSD performance may arise from the used PSD algorithm. To avoid this problem, a new PSD algorithm in the frequency domain is presented and its excellent performance at low sampling frequencies is experimentally demonstrated. At the sampling frequency of 32 MHz, a Figure-of-Merit (FOM) of 1.31±0.04 in the light output range of 200-1400 keVee (electron equivalent energy) is achieved with an ADC of 10-bit resolution.
Nakhostin M. (2019) A General-Purpose Digital Pulse-Shape Discrimination Algorithm,IEEE Transactions on Nuclear Science Institute of Electrical and Electronics Engineers (IEEE)
Digital pulse-shape discrimination (PSD) systems are widely used to extract various kinds of information from the shape of output pulses of radiation detectors. Such systems replace the traditional analog PSD circuits with numerical algorithms running on a digital processor which makes them more flexible for implementing various PSD methods. However, the available digital PSD algorithms have been generally tailored to the characteristics of the concerned detectors which limits their general use. Here, for the purpose of building a general-purpose digital PSD module, we present a PSD algorithm that with minimum alterations can be used with a wide range of radiation detectors. Our approach is based on using the cosine similarity measure to quantify the variations in the shape of detectors? pulses with respect to the shape of a unit step pulse. The method is described in details, and the results of the test experiments with different types of radiation detectors, including a boron tetrafluoride (BF3) proportional counter, a liquid scintillation detector, and a high purity germanium (HPGe) detector are shown. The performance of the algorithm is also compared to that of the common rise-time discrimination method.
Nakhostin M., Taggart M.P., Sellin P.J. (2019) A digital pulse shortening method for the mitigation of pulse pile-up effect in scintillation radiation detectors,Journal of Instrumentation 14 P04012 pp. 1-9 IOP Publishing
The pulse pile-up effect can significantly degrade the spectroscopic performance of scintillation radiation detectors at high counting rates. This paper reports on a digital pulse processing method for shortening the duration of scintillation pulses, thereby alleviating the pulse pile-up effect. The method operates based on replacing the decay-time constant of the scintillation pulses with a shorter decay-time constant. The details of the digital algorithm are presented and the performance of the method at a high counting rate of 795 kHz is experimentally examined with a NaI(Tl) detector. The effects of the pulse shortening on the spectroscopic performance of the system are also discussed.
Taggart M.P., Nakhostin M., Sellin P.J. (2019) Investigation into the potential of GAGG:Ce as a neutron detector,Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 931 pp. 121-126 Elsevier

In this work we investigate the potential use as a thermal neutron detector of cerium-doped gadolinium aluminium gallium garnet (GAGG:Ce) coupled to a silicon photomultiplier (SiPM). The response to thermal neutrons has been measured, with two strong low energy neutron-indicative peaks clearly identifiable below 100 keV and additional ³ peaks at higher energies. The neutron-related peaks are produced by a combination of contributions from excited states of the two isotopes 156Gd and 158Gd which can be clearly resolved in our GAGG scintillation detector. In particular, two peaks due to neutron-induced ³-ray emission are observed at approximately 82 keV and 260 keV, with best achieved energy resolutions of 24.1 ± 0.2% and 22.7 ± 0.7% respectively. Three different scintillator volumes (0.1 cm3, 0.4 cm3, and 1 cm3) were investigated and the respective results for each configuration will be presented.

Our findings show that a GAGG-SiPM based detector can be used as a compact, efficient thermal neutron detector in a low ³-ray contamination environment.

Rudigier M., Canavan R.L., Regan P.H., Söderström P.-A., Lebois M., Wilson J.N., Jovancevic N., Bottoni S., Brunet M., Cieplicka-Orynczak N., Courtin S., Doherty D.T., Hadynska-Klek K., Heine M., Iskra W., Karayonchev V., Kennington A., Koseoglou P., Lotay G., Lorusso G., Nakhostin M., Nita C.R., S. Oberstedt S., Podolyak Zs., Qi L., Régis J.-M., Shearman R., Walker P.M., Witt W. (2019) Isomer spectroscopy and sub-nanosecond half-live determination in 178w using the NuBall array,Acta Physica Polonica B 50 (3) pp. 661-667 Jagiellonian University
The reaction of a pulsed 18O beam on a 164Dy target was studied in
the first experiment with the NuBall array at the IPN Orsay, France. Excited
state half-lives were measured using the fast timing method with 20
LaBr3(Ce) detectors. The timing characteristics of the fully digital acquisition
system is briefly discussed. A value for the previously unknown
half-life of the first excited 4+ state in 178W is presented.
Rudigier M., Walker P. M., Canavan R.L., Podolyak Zs., Regan P. H., Söderström P.-A., Lebois M., Wilson J.N., Jovancevic N., Blazhev A., Benito J., Bottoni S., Brunet M., Cieplicka-Orynczak N., Courtin S., Doherty D. T., Fraile L.M., Hadynska-Klek K., Heine M., Iskra A.W., Jolie J., Karayonchev V., Kennington A. R., Koseoglou P., Lotay G., Lorusso G., Nakhostin M., Nita C.R., Oberstedt S., Qi L., Régis J.-M., Sánchez-Tembleque V., Shearman R., Witt W., Vedia V., Zell K.O. (2020) Multi-quasiparticle sub-nanosecond isomers in 178W,Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 801 135140 Elsevier
We report on the first measurement of the half-lives of and four-quasiparticle states in the even-even nucleus 178W. The sub-nanosecond half-lives were measured by applying the centroid shift method to data taken with LaBr3(Ce) scintillator detectors of the NuBall array at the ALTO facility in Orsay, France. The half-lives of these states only became experimentally accessible by the combination of several experimental techniques - scintillator fast timing, isomer spectroscopy with a pulsed beam, and the event-by-event calorimetry information provided by the NuBall array. The measured half-lives are and for the and states, respectively. The decay transitions include weakly hindered E1 and E2 branches directly to the ground-state band, bypassing the two-quasiparticle states. This is the first such observation for an E1 transition. The interpretation of the small hindrance hinges on mixing between the ground-state band and the t-band.