Response to the COVID-19 Pandemic: Physics Teaching in India

When academic institutions in India closed abruptly in March 2020 due to the COVID-19 pandemic, formal education moved online. This transition had a very uneven impact given the significant digital divide between rural and urban India and the unequal distribution of digital resources in different institutions. Access to resources varied substantially by individual, based on socioeconomic factors as well as gender. Institutional support to the academic community during this critical period was largely inadequate, which has had serious consequences on the teaching of physics and other subjects that require laboratory instruction. Educational institutions also provide safe and enabling learning spaces for women students; reduced access to such facilities undermined the work- and study-related dynamics for women because of the scarcity of resources such as devices, data, and time. This paper reports on efforts made towards understanding such challenges during the COVID-19 pandemic and describes steps that were taken to address them.Comment: 5 pages, 3 figure

Search for neutrinoless double beta decay in

The mass and nature of neutrinos play an important role in theories beyond the standard model. The nuclear β decay and double beta decay can provide the information on absolute effective mass of the neutrinos, which would represent a major advance in our understanding of particle physics. At present, neutrinoless double beta decay (0νββ) is perhaps the only experiment that can tell us whether the neutrino is a Dirac or a Majorana particle. Given the significance of the 0νββ, there is a widespread interest for these rare event studies employing a variety of novel techniques. An essential criterion for detector design is the high energy resolution for a precision measurement of the sum energy of two electrons emitted in 0νββ decay. The low temperature bolometric detectors are ideally suited for this purpose. In India, efforts have been initiated to search for 0νββ in 124Sn at the upcoming underground facility of India based Neutrino Observatory (INO). A custom built cryogen free dilution refrigerator has been installed at TIFR, Mumbai for the development of Sn prototype bolometer. A base temperature of 10 mK has been achieved in this setup. This paper gives a brief description of efforts towards Sn bolometer development

Study of fusion in

Excitation functions are measured for complete fusion and transfer reactions of 6Li and 7Li with 197Au at energies around the Coulomb barrier. Coupled channel calculations including the couplings to both target and projectile excited states have been performed and are found to explain the data at energies below the barrier. At above barrier energies the complete fusion cross sections are found to be suppressed compared to the coupled channel calculations for both the systems. A systematic comparison of fusion cross-section for halo nuclei 6,8He and weakly bound stable nuclei 6,7Li on 197Au target is also presented. Large neutron transfer cross-sections are observed for 6,7Li as compared to tightly bound projectiles 12C,16O

Photomixing and photoconductive THz generation improvement in SI-GaAs after carbon irradiation

We report significant improvement in pulsed and continuous wave (CW) THz generation when semi insulating GaAs (SI-GaAs) is irradiated with carbon ions. Irradiation reduces the carrier lifetime in SI-GaAs and increases its resistivity. This results in reduced screening effects and lesser heat dissipation in the THz pulse emitter. Reduced lifetime significantly improves the bandwidth of the CW THz system