Narrow Results

Proton Induced X-ray Emission Technique (PIXE) has been used in analyzing Gold standards of 22, 20, 18, and 14 karats with a proton beam of Energy 3.3 MeV at the newly commissioned Folded Tandem Ion Accelerator (FOTIA) at B.A.R.C, Trombay. Well resolved Au and Ag X-rays were detected at a current of 3 nA. Percentage values of gold and silver were calculated and were checked with those obtained by Energy Dispersive X-ray Fluorescence (EDXRF) Method and were found to be in agreement with the certified values as well as those obtained by XRF.

Proton Induced X-ray Emission (PIXE) and Energy Dispersive X-ray Fluorescence (EDXRF) techniques have been used for elemental characterization of offset printing ink tagged with rare-earth taggants. The offset printing ink was tagged with rare-earth (La, Pr, Nd, Sm, Eu and Gd) thenoyltrifluoroacetonate chelates at about 1000-ppm level for each element separately. Small aliquots (approximately 20 mg) of tagged inks were coated on paper supports in the form of small circles having diameter 10–15 mm each and then analyzed. In the case of PIXE, a proton beam of energy 4 MeV and in the case of EDXRF a radioisotope source of ²⁴¹Am (100 mCi) was used to excite the samples. The PIXE analysis showed well-resolved rare-earth L X-rays and EDXRF analysis showed the K X-rays of rare earths. Satisfactory results to identify and quantify the taggants were achieved.

The low-lying states of ⁷¹Ge have been studied the via the ⁷¹Ga (p,n γ)⁷¹Ge reaction using proton beam energies of 2.5–4.3 MeV. The angular distributions have been used to assign the spins and the multipole mixing ratios using statistical theory for compound nuclear reactions. The ambiguity in the spin values for the various levels has been removed. The multipole mixing ratios for a few γ-transitions have been newly measured. The lifetimes of the levels at 747.0, 808.0, 831.1, 1377.8, 1406.6, 1414.4, 1422.1, 1558.8 and 1566.1 keV excitation energies have been measured for the first time using the Doppler shift attenuation method.

The excited states of ⁷³As have been investigated via the ⁷³Ge(p, nγ)⁷³As reaction with proton beam energies from 2.5–4.3 MeV. The lifetimes of the levels at 769.6, 860.5, 1177.8, 1188.7, 1274.9, 1344.1, 1557.1 and 1975.2 keV excitation energies have been measured for the first time using the Doppler shift attenuation method. The angular distributions have been used to assign the spins and the multipole mixing ratios using statistical theory for compound nuclear reactions. The ambiguity in the spin values for the various levels has been removed. The multipole mixing ratios for eight γ-transitions have been newly measured.

J-PARC Hadron Experimental Facility is designed to carry out a variety of particle and nuclear physics experiments with intense secondary particles generated by 750 kW proton beams. The first construction stage including the experimental hall, the primary beam line, and one secondary beam line (K1.8BR) has been completed at the end of December 2008. In order to handle the high intensity primary beam safely, we have developed many special devices working under severe radiation environment. The present article reports the current status of the Hadron Experimental Facility in detail.

For a sustainable nuclear energy program using fission reactors, the reduction or elimination of long-lived radioactive waste is essential. The hazardous Long-Lived Fission Products (LLFP), which are by-products of the operation of nuclear reactors, need to be converted to short-lived or stable nuclei. For nuclear transmutation, the knowledge of reaction cross-sections is important. The cross-section and half-life for the proton-induced transmutation of the LLFP, ${}^{126}$Sn, produced as nuclear waste from the reactor have been calculated. The cross-section for the (p,n) reaction on unstable ${}^{126}$Sn has been calculated using phenomenological as well as microscopic models of optical potentials and level densities in the framework of the statistical nuclear model using the latest version of the code TALYS-1.96. The Koning–Delaroche (KD) and Jeukenne–Lejeune–Mahaux–Bruyeres (JLMB) optical models, as well as back-shifted Fermi gas model (BFM) and Hartree–Fock (HF) level density, based on the Skyrme force from Gorielys tables, have been used. The renormalized optical model parameters and level density models obtained by comparing cross-sections with data for protons incident on stable ${}^{112,114,115,116,117,118,119,120,122,124}$Sn isotopes were extended to make a prediction of (p,n) cross-section on unstable ${}^{126}$Sn isotope. The excitation function obtained using JLMB-HF calculation for ${}^{126}$Sn reveals a peak at an incident proton energy of 8.5MeV with a corresponding cross-section of 269mb. It would be of interest to perform experiments for measurements of cross-section where data are unavailable, especially in the peak regions and beyond, to validate the predictions of this work. It is found that for a proton flux of $6.25\times 10^{14}$s${}^{-1}$cm${}^{-2}$, and a peak cross-section calculated using JLMB-HF calculation, the effective half-life of transmutation of ${}^{126}$Sn is about 65 years, thus justifying its feasibility.

J-PARC Hadron Experimental Facility is designed to carry out a variety of particle and nuclear physics experiments with intense secondary particles generated by 750 kW proton beams. The first construction stage including the experimental hall, the primary beam line, and one secondary beam line (K1.8BR) has been completed at the end of December 2008. In order to handle the high intensity primary beam safely, we have developed many special devices working under severe radiation environment. The present article reports the current status of the Hadron Experimental Facility in detail.