Authors:K. Ramakumar, P. Khodade, A. Parab, S. Chitambar, and H. Jain
Application of dicesium metaborate ion /Cs2BO
/ in Thermal Ionisation Mass Spectrometry /TIMS/ for the determination of boron present at sub ppm level in heavy water moderator as well as for the isotopic composition of boron in boron carbide is reported. Contamination of samples with natural boron while determining trace levels of boron in heavy water was checked by analysing SRM-952 isotopic reference material. The atom ratios of boron in B4C were determined by directly fusing the material on the tantalum filament with Cs2CO3 as well as with Na2CO3 and also by following the conventional fusion procedures and the results were compared.
Authors:S. Aggarwal, G. Chourasiya, C. Singh, A. Rawat, S. Chitambar, and H. Jain
A method is described for the determination of plutonium concentration in the presence of a bulk of other impurities by isotope dilution mass spectrometry /IDMS/ using239Pu as a spike. The method involves the addition of239Pu spike / 90 atom%/ to samples with239Pu / 70 atom%/ and vice versa. After ensuring chemical exchange between the sample and the spike isotopes, plutonium is purified by conventional anion exchange procedure in 7M HNO3 medium.239Pu/240Pu atom ratio in the purified spiked sample is determined with high precision /better than 0.1%/ using a thermal ionization mass spectrometer. Concentration of plutonium in the sample is calculated from the changes in239Pu/240Pu atom ratio in the spiked mixture. Results obtained on different plutonium samples using239Pu as a spike are compared with those obtained by the use of242Pu spike. Precision and accuracy comparable to those achieved by using242Pu are demonstrated. The method provides an alternative in the event of non-availability of enriched242Pu or244Pu required in IDMS of plutonium and at the same time, offers certain advantages over the use of242Pu or244Pu spike.
Authors:K. Ramakumar, A. Parab, P. Khodade, A. Almaula, S. Chitambar, and H. Jain
Investigations were carried out on the determination of isotopic composition of boron using Cs2BO
ion and thermal ionisation mass spectrometry. The results show distinct advantage over the normally used Na2BO
Authors:S. Aggarwal, A. Almaula, P. Khodade, A. Parab, R. Duggal, C. Singh, A. Rawat, G. Chourasiya, S. Chitambar, and H. Jain
K-factors (= certified isotope ratio/observed isotope ratio) are determined for the isotope abundance measurements of uranium and plutonium by thermal ionisation mass spectrometry. An mdf of 0.07% and 0.18% per mass unit differing by a factor of about 3, is obtained for uranium and plutonium, respectively, employing double rhenium filament assembly in the ion source and Faraday cup as the detector using the presently available isotopic reference materials of uranium and plutonium.