GAS-JET COUPLED ISOL SYSTEM AT VECC.

A gas-jet recoil transport (GJRT) system at VECC is being extensively use for the study of short-lived nuclei. A transport efficiency of approximately 70-90% has been obtained for a large number of elements at a distance of approximately 40 ft using a 1. 27 mm tygon capillary. For the same distance, a transit time of approximately 900 ms has been obtained using a pressure differential of 1 atmosphere. To extend the capability of the present system, a mass separator coupled to the GJRT has been designed. The integrated system will consist of a GJRT system, a skimmer, an ion-source, a beam transport system and a tape-transport type detection assembly. The beam optics of a 90 degree analyser magnet have been computed using the code ODESSA developed at VECC. A mass resolving power of approximately 600 and a dispersion of approximately 2. 36 m have been estimated including second order aberrations. With reduced capillary length, the facility should allow the study of nuclides with half-lives approximately 100 ms.