ASET Colloquium

Search for energetic light quanta from fission in a dark matter laboratory

by Dr. Tilak Kumar Ghosh (Variable Energy Cyclotron Centre, Kolkata)

Friday, October 29, 2021 from to (Asia/Kolkata)
at Online ( )
A 555-meter-deep underground laboratory has recently been set up at the Uranium Corporation of India Limited (UCIL), Jaduguda, Jharkhand, India primarily to carry out dark matter search experiments. The first Physics experiment that we performed in the lab, however, was not on dark matter search; rather it addresses a long-standing, debated and fundamental problem of nuclear fission physics.

Several experiments carried out worldwide in the last few decades, claimed the observation of energetic light quanta (gamma rays > 25 MeV) accompanying the fission process and even explained the results in the framework of the nucleus-nucleus coherent bremsstrahlung theories. However, the experimental findings are contradictory in nature and more importantly, do not comprehend by the fission school of thought. The measurement of high-energy gamma rays above 25 MeV is complicated due to the low probability of emission as well as due to the large cosmic-ray background that could be efficiently excluded for the first time in our experiment in which we measured the gamma-ray spectrum from the spontaneous fission of Californium at the Jaduguda underground laboratory. The results of the experiment will be discussed. The challenges and joy of doing an experiment, carried over more than a year-long time in a mine turned into a lab, will be shared in this colloquium.

About the Speaker:
Dr. Tilak Kumar Ghosh is currently a scientist at the Variable Energy Cyclotron Centre (VECC) and Dean of Students’ Affairs at the VECC - Homi Bhabha National Institute. He graduated from the Saha Institute of Nuclear Physics and was a K.S. Krishnan Research Associate at the Department of Atomic Energy. He was a visiting scientist (2009 -10) at the National Superconducting Cyclotron Laboratory at Michigan State University. Dr. Ghosh is the recipient of the Young Scientist Award (2008) and Scientific and Technical Excellence Award (2016) of the Department of Atomic Energy.
Organised by Dr. Satyanarayana Bheesette