Trajectory calculations were performed using the three-point-charge model. The input parameters took values distributed over a wide range. Using experi mental distributions, each trajectory was assigned a ‘weight’; and the trajectories and their statistical ‘weights’ were used in obtaining initial distributions which in turn reproduced other experimental distributions, such as the angular distribution ofα-particles, very well. Some information about the initial distributions has been obtained. The effect of the anticorrelation, between the finalα and fragment energies, on the initial distributions has been examined.

The yields and energy spectra of light charged particles emitted in the fission of²³⁵U have been measured in the neutron energy range of 100 keV to 1 MeV. The yield of long range alpha particles is found to increase around 200 keV neutron energy compared to thermal fission. A low energy component observed in the energy spectrum was assigned to the tritons emitted in fission. The yield of this triton component is seen to have a marked increase around 500 keV. These results indicate that LCP yield is influenced by the transition state level characteristics.

The yield and energy distribution of long-range alpha-particles (lra) emitted from neutron-induced fission of²³⁵U have been measured at neutron energies; thermal, 125±12, 155±11, 185±10, 210±9, 240±9, 365±50 and 480±45 keV. The long-range alpha-particles were detected in cellulose nitrate track detector foils. Results showed an increase of about 50% in the yield at neutron energies in the region 150 keV≤E_n≤220 keV as compared to that of thermal neutrons. A calculation has been carried out to extract thelra to binary fission ratio forp-wave neutron induced fission.

The angular distribution of long-range alpha particles emitted in keV-neutron induced fission of²³⁵U has been measured using a technique which employs only a particle telescope to derive the angular information. The neutron energy region investigated is 100 keV-1 MeV. The angular distribution oflras has been found to be peaked perpendicular to the neutron-direction with a substantial amount of anisotropy near 200 keV.

The emission of light charged particles in the fission process is of interest as they are believed to emerge from the neck region of the deformed fissioning nucleus at a time close to the scission point and may thus prove a useful probe to investigate the last stages of fission close to the rupture point. Experimental results on light charged particle emission and the efforts made to obtain information about the scission point parameters therefrom are reviewed.

Understanding the dynamics of vortex matter subjected to random and correlated pinning disorders in layered superconductors remains a topic of considerable interest. The dynamical behavior of vortices in these systems shows a rich variety of effects due to many competing interactions. Here, we study the ac response of as-grown as well as heavy-ion-irradiated Tl₂Ba₂CaCu₂O₈ (Tl-2212) thin films by using a micro Hall-probe susceptometer. We find that the dynamics of vortices in the high-temperature, low-field regime of the H-T phase diagram investigated here depends on the nature of pinning defects. While the decay of screening currents J(t) indicates a glassy behavior in both types of samples, the nature of the glassy phase is different in the two cases. Samples with columnar defects show distinct signature of a Bose glass in the measurement of J(t) and the angular dependence of the irreversibility field (B irr).

Developments of ion accelerator and associated facilities in India are presented. Various types of accelerator facilities which are systematically built in the country through sustained development and research programs at various research centres and institutions are highlighted. Impact of accelerator in different interdisciplinary fields of research are highlighted.