239-F
Part A (Experimental): Nuclear structure studies with heavy-ion fusion reaction
> Nuclei excited to high-spin states (several MeV) using the 14 MV Pelletron accelerator at TIFR (Mumbai) or IUAC (New Delhi).
> Spectroscopic properties of nuclei were investigated by detecting photons with the Indian National Gamma Array (INGA).
> Measurement (using the DSAM technique) of short lifetimes (ps-fs) provides stringent tests to various theoretical models.
> Phenomena studied: (i) Nuclear Chirality, (ii) Shape coexistence, (iii) Signature aspects, (iv) Different nuclear shapes – prolate, oblate and triaxial.
Part B (Simulation-based): Imaging with scattered photons in Positron emission tomography (PET)
> Conventional PET-imaging discards the Compton scattered part ( 40% of total events), creating noise.
> Using list-mode data, it is possible to isolate the single tissue-scattered events because the locus of the scattering point is a prolate spheroid or spindle toroid.
> We developed a model to recognise the scattered events and create images. The idea is to add the images from the scattered events to the original PET data.
> Finally, instead of discarding the scattered data as noise, we can utilise them, significantly improving the statistical image quality.
Future direction:
1) Polarization entanglement of annihilation photons to be used in event selection.
2) Experimental verification of our simulation results using J-PET (Krakow, Poland).
Recent Journal Publications:
Part A
1) Bhushan Bhujang, Pragya Das “Towards understanding Incomplete fusion reactions at low beam energies: Modified Sum rule model”, Atoms 11 (2023) 106.
2) Umakant Lamani, Pragya Das et al. “Lifetime measurement in picoseconds for the excited states of 129Cs”, Nucl. Phys. A 1014 (2021) 122220.
3) Umakant Lamani, Pragya Das and S. G. Wahid “The study of signature inversion in 123,125I using Particle Rotor Model calculations”, Int J. Mod. Phys. E 30, No. 7 (2021) 2150062.
4) Pragya Das, Umakant Lamani, Himanshu Kumar Singh “Shapes and Symmetries in A 130 Nuclei: A Perspective through Measured Transition Probabilities”, Bulg. J. Phys. 48 (2021) 645.
5) Pragya Das, Himanshu Kumar Singh, Umakant Lamani “Nuclear shapes and symmetries seen through measurement of short lifetimes”, Acta Phys. Pol B 51 (2020) 103.
6) Vinod Kumar, Pragya Das “Identification of 38 keV gamma-transition in 132La amidst x-rays”, Acta Phys. Pol. B 50, No. 2 (2019) 173.
7) Himanshu Kumar Singh, Pragya Das et al. “Investigation of signature inversion in 126I through lifetime measurements”, Phys. Rev. C 100 (2019) 064306.
Part B
8) Satyajit Ghosh, Pragya Das “Single-cell tracking with Compton-PET: An in silico feasibility study”, Nucl. Instr. Meth. Phys. Res. A 1053 (2023) 168373.
9) Satyajit Ghosh, Pragya Das “Improvement of CNR in low-count PET scans using tissue-scattered data as initial estimate in non-TOF MLEM reconstruction”, Biomed. Phys. Eng. Express 9 (2023) 035023.
10) Satyajit Ghosh, Pragya Das “Feasibility study of imaging with tissue-scattered triple-𝜸 coincidence events in Compton-PET”, J. Inst. 17 (2022) P05040.