B. K. Nayak

An annular ionization detector for quasi-elastic and transfer reaction studies

An annular ionization chamber detector has been developed to study quasi-elastic and transfer reactions in heavy-ion collisions at near-barrier and sub-barrier energies. The important feature of the detector is that it has a near 2π coverage in the azimuthal angle φ for the particles entering in the detector at a given θ direction. This feature makes the detector very useful for measurement of the differential cross-sections at backward angles with respect to the beam direction, involving low cross-section reaction channels. The split anode configuration of the detector makes it capable of both particle identification and energy measurement for heavy ions and fission fragments. The detector has been tested using heavy-ion beams from the 14 MV-pelletron accelerator at Mumbai. Results on quasi-elastic excitation function measurements and barrier distribution studies in many heavy-ion reactions using this detector setup are discussed.

A Bi-Dimensional Multi-Wire Cathode Strip Detector for Fission Fragments

A large area bi-dimensional position sensitive multi-wire cathode strip detector (MCSD) has been developed for the detection of fission fragments (FFs). The performance of the detector has been characterized with FFs from 252Cf and α particles from 241Am-239Pu sources. The position information is obtained from the measurement of time delay signals of the cathode strips (X-direction) and split-cathode wires (Y-direction) with respect to the timing signal from the anode wires. The position resolution is found to be about 1.0 and 1.5 mm in X-and Y-directions respectively.