B L Ahuja
Articles written in Pramana – Journal of Physics
Volume 65 Issue 1 July 2005 pp 137-145
In this paper, we present the design and construction of a 20 Ci γ-ray Compton spectrometer that employs a137 Cs source with a strong line at 661.65 keV. The total resolution of the spectrometer in momentum scale is 0.40 a.u., which is much better than the conventional241Am Compton spectrometers. The in-house137Cs spectrometer is very useful for the measurement of momentum densities of heavy materials. The performance of the machine is assessed using aluminum, terbium and mercury samples and the experimental data from comparable apparatus.
Volume 65 Issue 1 July 2005 pp 159-164
methodology for bremsstrahlung (BS) background correction to extract a true Compton profile in high-energy Compton scattering experiments is presented. The BS background profiles for Hg, computed within the Born approximation, are estimated for different values of incident energy. It is seen for the first time that the BS background contribution in high-energy Compton profile experiments like those employing third generation synchrotron radiation sources comes out to be significant and non-linear. Further, it is found that the incorporation of BS correction in data reduction of such an experiment performed on Hg at 662 keV energy helps in reconciliation of theory and experiment.
Volume 68 Issue 1 January 2007 pp 91-98 Research Articles
In this paper, we report the first-ever isotropic Compton profile of hafnium measured at an intermediate resolution, with 661.65 keV 𝛾-radiation. To compare our experimental data, the theoretical computations have also been carried out within the framework of pseudopotential using CRYSTAL03 code and the renormalized-free-atom (RFA) model. It is found that the present experimental profile is in better agreement with the RFA calculations if the outer electronic configuration is chosen as 5d3.26s0.8. The cohesive energy of Hf is also deduced from the experimental data and is compared with the available data.
Volume 68 Issue 5 May 2007 pp 843-850 Research Articles
In this paper, a new design and construction of a low intensity (100 mCi) 241Am 𝛾-ray Compton spectrometer is presented. The planar spectrometer is based on a small disc source with the shortest geometry. Measurement of the momentum density of polycrystalline Al is used to evaluate the performance of the new design. The measured proﬁle is in good agreement with the existing theoretical data and our density functional calculations.
Volume 74 Issue 6 June 2010 pp 1017-1027 Research Articles
We have carried out an extensive study of electronic properties of silver iodide in 𝛽- and 𝛾-phases. The theoretical Compton profiles, energy bands, density of states and anisotropies in momentum densities are computed using density functional theories. We have also employed full-potential linearized augmented plane-wave method to derive the energy bands and the density of states. To compare our theoretical data, isotropic Compton profile measurement on 𝛾-AgI using 137Cs Compton spectrometer at an intermediate resolution of 0.38 a.u. has been undertaken. The theoretical anisotropies are also interpreted on the basis of energy bands.
Volume 93 | Issue 5
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