Md. Shuza Uddin

Experimental cross section for the 139La(n, γ)140La reaction at 0.0536 eV

Abstract The neutron capture cross section for the 139La(n, γ) 140La reaction at 0.0536 eV was measured for the first time using monochromatic neutrons coming from a Triple Axis Spectrometer at the TRIGA Mark-II reactor. The neutron beam intensity was determined by irradiating Au-monitor foil together La2O3 target. The radioactivity of the products was determined via high resolution γ-ray spectrometry. The obtained cross section value is 6.13±0.3 b, which is 1.34% and 0.21% lower than that in the ENDF/B-VII and JENDL-3.3 data library, respectively.

Experimental determination of deuteron-induced activation cross sections of yttrium

Excitation functions were measured for the 89Y(d,x)90m,88,87m,87m+g Y, 89Y(d,x)88,89Zr and 89Y(d,x) 85Sr reactions in the energy range 9–40 MeV by the stacked-foil activation technique in combination with high resolution HPGe γ-ray spectroscopy. The data above 27 MeV have been measured for the first time. Yield calculations revealed that in the deuteron-induced activation of yttrium the direct production of 88Y is about two times lower than that of 88Zr. The maximum cross section for the production of the PET isotope 89Zr by the Y+d process is higher than by Y+p. The yields and decay characteristics of the 88Y and 88Zr nuclides are suitable for thin layer activation (TLA) analysis.

Experimental determination of proton induced reaction cross sections on natNi near threshold energy

Abstract A newly developed facility at the 3 MV Tandem Accelerator at Dhaka for measurement of proton induced reaction cross sections in the energy region below 5 MeV is outlined and tests for the beam characterization are described. The results were validated by comparison with the well-known excitation function of the 64Ni(p, n)64Cu reaction. Excitation functions of the reactions natNi(p, x)60,61Cu, natNi(p, x)55,57,58m+gCo and natNi(p, x)57Ni were also measured from threshold to 16 MeV using the stacked-foil technique, whereby irradiations were performed with 5 MeV protons available at the Tandem Accelerator and 16.7 MeV protons at the BC 1710 cyclotron at Jülich, Germany. The radioactivity was measured using HPGe γ-ray detectors. A few results are new, the others strengthen the database. In particular, the results of the reaction natNi(p, x)61Cu below 3 MeV could serve as beam monitor.

Excitation functions for production of 88Zr and 88Y by proton and deuteron irradiation of Mo, Nb, Zr, and y

Cross sections for production of 88Zr and 88Y were measured for proton and deuteron induced nuclear reactions on Mo, Nb, Zr and Y targets up to 80 MeV proton and 50 MeV deuteron energy. Stacked foil activation technique and high‐resolution γ‐spectrometry were used for irradiation and for detection of the radioactive residuals. The experimental data up to Ep=100 MeV and for Ed=50 MeV were compared with the earlier literature data and with the theoretical calculations based on the ALICE‐IPPE code. Production yields of the different production routes are compared.

Radiochemical measurement of neutron-spectrum averaged cross sections for the formation of 64Cu and 67Cuvia the (n,p) reaction at a TRIGA Mark-II reactor: Feasibility of simultaneous production of the theragnosticpair 64Cu/67Cu

Abstract Integral cross sections of the 64Zn(n, p)64Cu and 67Zn(n, p)67Cu reactions were measured for the fast neutron spectrum of TRIGA Mark-II reactor at Savar, Dhaka, Bangladesh. A clean radiochemical separation was performed to isolate the copper radionuclides from the target element zinc. The radioactivities produced in the irradiation were measured by HPGe γ-ray spectroscopy. The neutron flux over the energy range 0.5–20 MeV was determined using the 58Ni(n, p)58Co monitor reaction. The measured results amount to 28.9 ± 2.0 mb and 0.84 ± 0.07 mb for the formation of 64Cu and 67Cu, respectively. These values are slightly lower than the respective values for a pure fission spectrum. The present results were compared with data calculated using the neutron spectral distribution and the recently critically analysed excitation function of each reaction given in the literature. The good agreement validates the reliability of those excitation functions. The feasibility of simultaneous production of 64Cu and 67Cu with fast neutrons is discussed.

Excitation functions for the formation of some short-lived products in proton-induced reactions on silver

Summary Excitation functions of the natAg(p,xn)104,105Cd and natAg(p,pxn)103,104m,g,104gAg reactions were measured for the first time over the proton energy range of 32 to about 60 MeV. The data were compared with the results of precompound-hybrid model calculations, whereby only partial agreement was obtained. The contribution of the 103Ag precursor decay to the total formation of the therapeutic radionuclide 103Pd in proton activation of silver was estimated: it amounted to about 70%. The various possible routes for the production of 103Pd were also considered: the natAg(p,x) 103Pd and 103Rh(p,n) 103Pd processes were found to be most interesting. Despite its somewhat lower yield, the latter process is preferred because it can be applied at a low-energy cyclotron.

Ion-exchange separation of radioiodine and its application to production of 124I by alpha particle induced reactions on antimony

Abstract The basic parameters related to radiochemical separation of iodine from tellurium and antimony by anion-exchange chromatography using the resin Amberlyst A26 were studied. The separation yield of 124I amounted to 96% and the decontamination factor from 121Te and 122Sb was > 104. The method was applied to the production of 124I via the 123Sb(α, 3n) reaction. In an irradiation of 110 mg of natSb2O3 (thickness ∼ 0.08 g/cm2) with 38 MeV α-particles at 1.2 μA beam current for 4 h, corresponding to the beam energy range of Eα = 37 → 27 MeV, the batch yield of 124I obtained was 12.42 MBq and the 125I and 126I impurities amounted to 3.8% and 0.7%, respectively. The experimental batch yield of 124I amounted to 80% of the theoretically calculated value but the level of the radionuclidic impurities were in agreement with the theoretical values. About 96% of the radioiodine was in the form of iodide and the inactive impurities (Te, Sb, Sn) were below the permissible level. Due to the relatively high level of radionuclidic impurity the 124I produced would possibly be useful only for restricted local consumption or for animal experiments.

Small scale production of high purity 193mPt by the 192Os(α,ߙ3n)-process

Abstract Some production aspects of the Auger electron emitter 193mPt (T1/2=4.33 d) through the 192Os(α,ߙ3n)-process were investigated. Relatively thick targets of 99.65% enriched 192Os, prepared by pressing or electrolytic deposition, were irradiated with 40 MeV α-particles for 3 h at a nominal beam current of 1.6 μA. The radioplatinum formed was chemically separated with a yield of 90% and the expensive target material was recovered with a yield of 85%. The radioactivity of 193mPt was determined by high resolution X-ray spectrometry. The radionuclidic purity of 193mPt amounted to 99%, the level of 195mPt and 191Pt impurities being each 0.5%. The batch yield of 193mPt achieved was about 10 MBq with a specific activity of 1 GBq/μg Pt. Both the batch yield and the specific activity could be appreciably increased through improved targetry. A comparison of the cyclotron and reactor production routes of 193mPt shows that the (n,ߙγ) reaction leads to high production yields but the α-particle induced reaction results in a product of higher radionuclidic purity and four orders of magnitude higher specific activity of 193mPt.

Investigation of elemental and radiological contamination of soils in two shipyards in Chittagong, Bangladesh

Abstract An analysis of metallic elements and natural radioactivity in soils collected from two shipyards and their surroundings in Chittagong, Bangladesh is presented. The elemental concentrations of the metals Cr, Mn, Fe, Ni and Cu were obtained by PIXE analysis with a 3 MV Tandem Accelerator, and the radioactivity of 226Ra, 232Th and 40K was determined using HPGe gamma-ray spectrometry. From the mean specific activities of the three radionuclides in soil samples, the radium equivalent activity, the gamma absorbed dose rate, the annual effective dose rate and the external hazard index were calculated. The study was focused on investigation of soil contamination via shipbreaking activities, if any. The somewhat higher contents of Cr, Mn, Fe, Ni and Cu in soil samples of shipyards, as compared to other locations, seem to be caused by the shipbreaking activities. The specific radioactivities as well as radium equivalent activity in soils of shipyards are also higher and thus possibly an indirect result of shipbreaking activities.

Fast neutron spectrum unfolding of a TRIGA Mark II reactor and measurement of spectrum-averaged cross sections: integral tests of differential cross sections of neutron threshold reactions

Summary The spectrum of fast neutrons having energies from 0.5 to 20 MeV in the core of the 3MW TRIGA Mark II reactor at Savar, Dhaka, Bangladesh, was unfolded by activating several metal foils to induce threshold nuclear reactions covering the whole spectrum, and then doing necessary iterative calculations utilizing the activation results and the code SULSA. The analysed shape of the spectrum in the TRIGA core was found to be similar to that of the pure 235U-fission spectrum, except for the energies between 0.5 and 1.5 MeV, where it was slightly higher than the fission spectrum. Spectrum-averaged cross sections were determined by integral measurements. The integral values measured in this work were compared with the recommended values for a pure fission spectrum as well as with the integrated data deduced from measured and evaluated excitation functions of a few reactions given in some data files. The good agreement between integral measurements and integrated data in case of well-investigated reactions shows that the fast neutron field at the TRIGA Mark II reactor can be used for validation of evaluated data of neutron threshold reactions.