نتایج جستجو برای: neutron detection

تعداد نتایج: 609986  

A. Vejdani-Noghreiyan, H. Miri-Hakimabad, H. Panjeh,

Background: Prompt gamma neutron activation analysis (PGNAA) is known as a non-invasive technique capable of measuring elemental concentration in voluminous samples in a short period of time. Also it is a valuable diagnostic tool for total body elemental measurements. 252Cf and 241Am-Be sources which are usually used in this method, generate not only neutrons, but also emit high-energy and unwa...

Journal: :iranian journal of radiation research 0
s.m. abtahi university of shahid beheshti, radiation medicine department, p. o. box 19839- 63113, tehran, iran s.m.r. aghamiri university of shahid beheshti, radiation medicine department, p. o. box 19839- 63113, tehran, iran h khalafi nuclear science and technology research institute (nstri), tehran, iran f. rahmani university of shahid beheshti, radiation medicine department, p. o. box 19839- 63113, tehran, iran

background: the aim of this work was to establish how well gel dosimeters performed, as substitutes for brain tissue compared with standard phantom materials such as water, polymethyl-methacrylate (or pmma), a150 plastic and te- liquid phantom material for dosimetry of neutron beams in boron neutron capture therapy. materials and methods: thermal neutron fluence, photon dose and epithermal neut...

ژورنال: سنجش و ایمنی پرتو 2020

In this study, the neutron and gamma doses in the dry channel and in the internal irradiation site of the Miniature Neutron Source research reactor (MNSR) has been calculated and measured. The MNSR reactor is a light water reactor with a maximum power of 30 kW and equipped with various irradiation facilities, including five irradiated sites, five irradiation sites and a dry channel. The interna...

2002
C. Sneden J. J. Cowan J. E. Lawler

Neutron-capture elements in low metallicity Galactic halo stars vary widely both in overall contents and detailed abundance patterns. This review discusses recent observational results on the n-capture elements, discussing the implications for early Galactic nucleosynthesis of: (a) the star-to-star " bulk " variations in the n-capture/Fe abundance ratios; (b) the distinct signature of rapid n-c...

2008
Victoria M. Kaspi Jessica R. Lackey Deepto Chakrabarty

We report the detection of a sudden spin-up of the 11 s anomalous X-ray pulsar 1RXS J170849.0−4000910 in regular timing observations made with the Rossi X-ray Timing Explorer. The event, which occurred between MJD 51446 (1999 September 25) and 51472 (1999 October 21), is well characterized by an increase in the rotational frequency of magnitude |∆ν/ν| = (6.2±0.3)×10−7 and an increase in the rat...

2011
H. J. KIM Wan Kim Sangjun KANG Kyeryung KIM Sangpil YUN

We report a fast neutron and gamma induced radiation dose and flux monitoring study during the nano-particle production at the proton beam irradiation facility. The monitoring results will be used for understanding of the activation of irradiated samples and the effect to the nano-particle production. A cylindrical shape of BC523A liquid scintillator was used for the fast neutron and gamma moni...

Journal: :Radiation research 2010
A Wallner W Rühm G Rugel N Nakamura A Arazi T Faestermann K Knie H J Maier G Korschinek

The detection of (41)Ca atoms in tooth enamel using accelerator mass spectrometry is suggested as a method capable of reconstructing thermal neutron exposures from atomic bomb survivors in Hiroshima and Nagasaki. In general, (41)Ca atoms are produced via thermal neutron capture by stable (40)Ca. Thus any (41)Ca atoms present in the tooth enamel of the survivors would be due to neutron exposure ...

2002
JOHN J. COWAN

Abundance observations indicate the presence of rapid-neutron capture (i.e., rprocess) elements in old Galactic halo and globular cluster stars. These observations demonstrate that the earliest generations of stars in the Galaxy, responsible for neutron-capture synthesis and the progenitors of the halo stars, were rapidly evolving. Abundance comparisons among large numbers of stars provide clue...

Journal: :iranian journal of radiation research 0
m.r. deevband department of biophysics, tarbiat modares university, tehran, iran p. abdolmaleki department of biophysics, tarbiat modares university, tehran, iran m.r. kardan nuclear sciences research school, radiation applications research school, tehran, iran h.r. khosravi nuclear sciences research school, nuclear sciences and technology research institute, tehran, iran m. taheri national radiation protection department, iranian nuclear regulatory authority, tehran, iran f. nazeri national radiation protection department, iranian nuclear regulatory authority, tehran, iran

background: the poly-allyl diglycol carbonate (padc) detector is of particular interest for development of a fast neutron dosimeter. fast neutrons interact with the constituents of the cr-39 detector and produce h, c and o recoils, as well as (n, α) reaction. these neutron- induced charged particles contribute towards the response of cr-39 detectors. material and methods: electrochemical etchin...

2009
T. C. Chan K. S. Cheng T. Harko H. K. Lau L. M. Lin W. M. Suen

The standard model for Type II supernovae explosion, confirmed by the detection of the neutrinos emitted during the supernova explosion, predicts the formation of a compact object, usually assumed to be a neutron star. However, the lack of the detection of a neutron star or pulsar formed in the SN 1987A still remains an unsolved mystery. In this paper we suggest that the newly formed neutron st...

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