Frau Shivani Ramachandran

Astroparticle Physics

Biografie

I’m Shivani Ramachandran, a graduate student in the Astroparticle Physics department at the University of Wuppertal (BUW). I completed my Master’s degree in Physics at RWTH Aachen University, where my thesis focused on reconstructing low-energy supernova neutrino events at the JUNO detector Before that, I earned my Bachelor’s degree with Honours in Physics from the University of Delhi. Prior to that, I earned my Bachelor's degree with Honours in Physics from the University of Delhi. Outside of research, I enjoy stargazing and have a keen interest in astronomy. My other interests include computing, reading, and hiking.
 

Abstract of current Project

Title: Influence of Terahertz Radiation on the Rydberg Background of KATRIN

The Karlsruhe Tritium Neutrino (KATRIN) experiment aims to determine the mass of the electron neutrino via a high-precision measurement of the tritium β-decay spectrum near its endpoint. This approach is independent of cosmological models and does not rely on whether the neutrino is a Dirac or Majorana particle. The goal is to reach a sensitivity of 0.2 eV (90% C.L.).

To achieve this, high source purity and ultra-low background levels are critical. However, the experiment currently experiences a background rate ten times higher than originally anticipated (over 100 mcps), with approximately 70% attributed to electrons from thermal ionization of neutral Rydberg atoms within the spectrometer volume.

One potential technique for confirming and mitigating this background is the application of terahertz (THz) radiation to stimulate de-excitation of these atoms. Observing a THz-frequency-dependent behavior in the background would directly support the Rydberg hypothesis.
 

Papers already presented:

Poster Presentations:

1. Precision Atomic Physics Experiments to Probe for New Physics, Wilhelm and Else Heraeus Seminar, Bonn, 2024

Talks:

1. Background Reduction in KATRIN using Terahertz Radiation, DPG (Particle Physics Division), Karlsruhe, 2024
2. Perturbations to Rydberg States due to Electric and Magnetic Fields in KATRIN, DPG (Atomic, Molecular, and Quantum Optics), Hanover, 2023
3. Background Reduction via Stimulated De-excitation of Rydberg Atoms, Heidelberg, 2022
4. Investigating the Rydberg Background Reduction in KATRIN, Dortmund, 2021
5. Neutrinos from Core-Collapse Supernovae in the JUNO Detector, Aachen, 2019

Other academic activities and memberships:

Member of Euro Python Society