12 research outputs found
Neutron Activation Analysis: Application in Geology and Medicine
Varied forms of neutron activation analysis (NAA), due to their high accuracy and reproducibility, are being used in geological studies and in medical application for the determination of concentration of elements down to the trace and ultra-trace level. Concentration of Cs, Sc, Fe, Ta, Co and Eu which may give rise to long-lived activity on neutron irradiation has been determined down to 0.1 ppm in rock samples from 11 geological formation in Karnataka, India, using NAA. NAA has been used by several authors to determine elemental concentration in biological shields, different geological formation around the world, thermal springs, archaeological objects and precious stones. NAA has been successfully employed by different groups to determine the concentration of Al, K, Na, Cl, Rb, Ca, Cu, Co, I, Mg, Se, Fe, Zn, Hg, Ba, Cr, etc. and their relative variation in breast cancer, skin cancer, colorectal cancer, dysfunction and malignancy of thyroid gland
Production Cross Sections and Induced Activity in Ge Isotopes by 30 MeV Proton Beam
The excitation functions of 70Ge(p,n)70As,72Ge(p,n)72As, 74Ge(p,n)74As and 76Ge(p,n)76As reactions were studied from reaction threshold to 30 MeV by using EMPIRE-3.2 and TALYS-1.9 nuclear reaction model codes. This study is important because some isotopes produced are important for positron emission tomography (PET). Direct, pre-compound and compound nuclear reactions are considered as main nuclear reaction mechanisms in the codes. The calculated excitation functions have been compared with available experimental data and found to be in fair agreement. Furthermore, the contributions of various reaction mechanisms have been studied in total reaction cross-section that varies with the incident proton energy. The estimation of induced radio activity in thick Ge target due to the primary interaction is carried out for1μA, 30 MeV proton beam
Production Cross Sections and Induced Activity in Ge Isotopes by 30 MeV Proton Beam
330-334The excitation functions of 70Ge(p,n)70As,72Ge(p,n)72As, 74Ge(p,n)74As and 76Ge(p,n)76As reactions were studied from reaction threshold to 30 MeV by using EMPIRE-3.2 and TALYS-1.9 nuclear reaction model codes. This study is important because some isotopes produced are important for positron emission tomography (PET). Direct, pre-compound and compound nuclear reactions are considered as main nuclear reaction mechanisms in the codes. The calculated excitation functions have been compared with available experimental data and found to be in fair agreement. Furthermore, the contributions of various reaction mechanisms have been studied in total reaction cross-section that varies with the incident proton energy. The estimation of induced radio activity in thick Ge target due to the primary interaction is carried out for1μA, 30 MeV proton beam
Radioactivity generation in Pb target by protons — A comparative study from MeV to GeV
761-765In an Accelerator
Driven Subcritical System (ADSS), choice of the target is decided by several
factors like neutron yield, heat generation, ease of cooling, possibility of
fire hazard, generation of chemically toxic elements and radioactive nuclides,
running cost of the accelerator, etc. natPb is one of the probable
targets for an ADSS. In the present work, we have estimated induced activity in
a natPb target by primary proton beam in the energy range of 20 MeV
up to 2.0 GeV using reaction model codes ALICE-91, TALYS-1.2, EMPIRE-2.19 and
QMD. The energy range studied spans the entire energy interval used for target
property study to practical application of an ADSS. At several hundreds of MeV,
some of the major contributors to induced activity are projectile-like
fragments, such as, 3H. The maximum
activity produced is of the order of 106-107 MBq
over the whole energy range. Some chemically toxic elements like Xe, Hg are
also formed in significant amount
Radiation environment in low energy accelerator for astrophysical studies
478-481Transmitted dose
through different thicknesses of ordinary concrete placed at different
distances from the target has been evaluated using simple Moyer model. It has
been observed that though the projectile energy is low, significant neutron and
gamma doses are produced at beam currents as high as 500 mA for protons. Some radioisotopes with half-lives of the order of a
few months are produced with activities of the order 1010-1011
Bq
Accelerator and radiation physics
"Accelerator and radiation physics" encompasses radiation shielding design and strategies for hadron therapy accelerators, neutron facilities and laser based accelerators. A fascinating article describes detailed transport theory and its application to radiation transport. Detailed information on planning and design of a very high energy proton accelerator can be obtained from the article on radiological safety of J-PARC. Besides safety for proton accelerators, the book provides information on radiological safety issues for electron synchrotron and prevention and preparedness for radiological emergencies. Different methods for neutron dosimetry including LET based monitoring, time of flight spectrometry, track detectors are documented alongwith newly measured experimental data on radiation interaction with dyes, polymers, bones and other materials. Design of deuteron accelerator, shielding in beam line hutches in synchrotron and 14 MeV neutron generator, various radiation detection methods, their characterization, dose mapping procedures and simulation of radiation environment are also discussed
Production of long-lived <sup>26</sup>Al and <sup>24</sup>Na from neutron interaction in Al target
509-512The excitation
functions of (n, 2n) and (n, α)
reactions for the production of long-lived radio nuclides 26Al and 24Na
from 27Al have been calculated for 1-20 MeV neutrons. The excitation
functions of these reactions are calculated using the codes ALICE-91,
EMPIRE-2.19 and TALYS-1.0. The codes account for the major nuclear reaction
mechanisms, including direct, pre-equilibrium and compound nuclear ones. The
excitation functions of these isotopes have been compared graphically with the
evaluated nuclear data file and available experimental data. The results are
more or less agreeing
up to which energy the experimental data are available whereas ALICE code
largely under predicts the data in the energy range 1-20 MeV.
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