Development of an X-ray detection system for particle identification of Super Heavy Nuclei

by Shayan Kumar, 1st year PhD student at GANIL

Very intense heavy ion-beams are now becoming available at the Superconducting Linear Accelerator (SPIRAL2-LINAC) facility of GANIL. This in turn will allow the production of Super-Heavy Nuclei (SHN), with highest atomic number, Z and N=Z nuclei close to the proton drip-line. The isotopes in these regions are mainly produced by fusion-evaporation reaction, but the production probabilities of these isotopes are extremely low and are mostly carried together with the unreacted beam particles and other reaction products in the beam direction. The separation of the ions of interest will be achieved to the highest possible degree using the Super Separator Spectrometer (S3) which is scheduled to be commissioned very soon.

To study the newly produced nuclei that have been separated with high precision with the help of S3, an efficient detection system is required. The SIRIUS (Spectroscopy and Identification of Rare Ions using S3) setup is one such compact and efficient detection system that will be utilized at the focal plane of the S3 for the spectroscopy of the exotic isotopes. The SIRIUS setup consists of a windowless silicon detector arrangement for detecting heavy ions and their subsequent decay ( by emmision of alpha particles, conversion-electrons, gammas, X-rays and fission fragments) energies with excellent time resolutions to identify the rarest of events. This is accompanied by a tracker and five germanium clover detectors for time-of-flight measurement and the measurement of the gamma decay energies, respectively.

Here, I will present the SIRIUS setup, the new X-ray detection system that is required to establish the atomic number of the SHN using the current SIRIUS setup, the necessary conditions for the new detectors and potential material options for the detectors. Also, I will talk briefly about the primary motivation behind the experiment proposed and accepted at Argonne National laboratory; the proper identification of the neutron deficient 244,245-Md isotopes. With the correct identification of these isotopes, they can be studied further for nuclear structure at the S3+SIRIUS facility of GANIL.