Moumita Maiti

New Short-Lived Isotope 221U and the Mass Surface Near N=126

Two short-lived isotopes ^{221}U and ^{222}U were produced as evaporation residues in the fusion reaction ^{50}Ti+^{176}Yb at the gas-filled recoil separator TASCA. An α decay with an energy of E_{α}=9.31(5)  MeV and half-life T_{1/2}=4.7(7)  μs was attributed to ^{222}U. The new isotope ^{221}U was identified in α-decay chains starting with E_{α}=9.71(5)  MeV and T_{1/2}=0.66(14)  μs leading to known daughters. Synthesis and detection of these unstable heavy nuclei and their descendants were achieved thanks to a fast data readout system. The evolution of the N=126 shell closure and its influence on the stability of uranium isotopes are discussed within the framework of α-decay reduced width.

Production and separation of 111In: an important radionuclide in life sciences: a mini review

Abstract111In is amongst the frequently used radionuclides in diagnostic nuclear medicine. Therefore its production and subsequent separation chemistry have been widely investigated since late 40s. 111In is commonly produced in proton or α-particle induced reactions on cadmium or silver targets. However, in recent past, various heavy ion (7Li, 11B, 12C etc.) activation routes have been proposed for its production. In this mini review, we have tried to portray the production routes of 111In and chemical separation methodologies reported so far in the literature in a concise form. A critical analysis presented in this review will be helpful to select suitable nuclear reaction and radiochemical method to produce high purity 111In for applications.

An attempt to explore the production routes of Astatine radionuclides: Theoretical approach

In order to fulfil the recent thrust of Astatine radionuclides in the field of nuclear medicine various production routes have been explored in the present work. The possible production routes of

Studies on stabilities of some human chorionic gonadotropin complexes with β-emitting radionuclides.

^{209-211}

Theoretical approach to explore the production routes of astatine radionuclides

At comprise both light and heavy ion induced reactions at the bombarding energy range starting from threshold to maximum 100 MeV energy. For this purpose, we have used the nuclear reaction model codes TALYS, ALICE91 and PACE-II. Excitation functions of those radionuclides, produced through various production routes, have been calculated using nuclear reaction model codes and compared with the available measured data. Contribution of various reaction mechanisms, like, direct, preequilibrium and equilibrium reactions, to the total reaction cross section has been studied using the codes. Result shows that equilibrium reaction mechanism dominates in all cases over other reaction mechanisms.

Production and separation of 97Ru from 7Li activated natural niobium

Human chorionic gonadotropin (hCG) is a peptide hormone, whose one of the structural subunits is identical to that of thyroid-stimulating hormone (TSH). As a consequence, the receptors of TSH also act as receptor for hCG hormone. Keeping in mind this interesting property of hCG we have studied the complex formation ability of various no-carrier-added β-emitting isotopes of (61)Cu (3.3 h), (62)Zn (9.2 h), (90)Nb (14.60 h) and (99)Mo (66.02 h) with hCG molecule. Stability of the hCG-M (M=metal ions) complexes was investigated by dialysis with respect to triple distilled water and ringer lactate solution, which has the same composition as extracellular fluid.

New routes for production of proton-rich Tc isotopes

To fulfill the recent thrust of astatine radionuclides in the field of nuclear medicine, various production routes have been explored in the present work. The possible production routes of {sup 209-211}At comprise both light- and heavy-ion-induced reactions at the bombarding energy range starting from threshold to a maximum of 100 MeV. Excitation functions of those radionuclides, produced through various production routes, have been calculated by using nuclear reaction model codes TALYS, ALICE91, and PACE-II and are compared with the available measured data. Contributions of various reaction mechanisms, such as direct, pre-equilibrium, and equilibrium reactions, to the total reaction cross section have been studied using the codes. Results show that the equilibrium reaction dominates in all cases over other reaction mechanisms.

Investigation on the production and isolation of 149,150,151Tb from 12C irradiated natural praseodymium target

Abstract The proton rich 97Ru, a potential candidate for nuclear medicine, was produced for the first time through the natNb(7Li,3n)97Ru reaction. A natural Nb foil of 20ߙmg/cm2 thickness was irradiated with 32ߙMeV 7Li beams to attain the yield of ∼1ߙMBq/μAߙh for 97Ru. The no-carrier-added 97Ru was separated from the bulk niobium by liquid–liquid extraction (LLX) and solid–liquid extraction (SLX) techniques. Liquid cation exchanger, di-(2-ethylhexyl)phosphoric acid (HDEHP) dissolved in cyclohexane was used in LLX and solid cation exchanger, DOWEX-50 was used for SLX in HCl. The LLX technique was found to be superior to the SLX technique with respect to radiochemical yield and purity of the radionuclide 97Ru.

Recent developments in nuclear data measurements and chemical separation methods in accelerator production of astatine and technetium radionuclides

For the first time two separate production routes of Tc radionuclides have been studied bombarding Li on Zr and Be on Y. Excitation functions of the evaporation residues produced in those reactions have been measured using stacked-foil technique followed by the γ-spectrometric studies in the energy range 37-45 MeV and 30-48 MeV respectively. Measured excitation functions have been compared with those calculated using the nuclear reaction model codes PACE-II and ALICE91. Experimental results show good agreement with the theoretical predictions. Compound nuclear reaction is the key mechanism in producing evaporation residues.

An empirical fit to estimated neutron emission cross sections from proton induced reactions

Abstract Short lived α-emitting radionuclides have enormous potential to be used in the targeted therapy. 149Tb (4.118 h) is among the few α-emitting radionuclides which are projected for human clinical use. Therefore, direct production of 149Tb was aimed from the 12C induced reaction on natural praseodymium target of 15 mg∕cm2 thickness at 71.5 MeV incident beam energy. No-carrier-added (nca) 149,150,151Tb radionuclides were produced in the target matrix along with 149Gd, which is also the decay product of 149Tb, with relatively high yield of 149Tb. An efficient radiochemical separation method was developed to separate nca 149–151Tb from bulk praseodymium and coproduced Gd by liquid–liquid extraction (LLX) using aqueous HCl and liquid cation extracting agent di-(2-ethylhexyl)phosphoric acid (HDEHP) dissolved in cyclohexane. Quantitative extraction of nca 149–151Tb was achieved from bulk target with a high separation factor of 4.7×105.