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Research Team
Poopalasingam Sivakumar, Ph.D.
Assistant Professor
Abstract
Over one half century has passed since the possible violation of time reversal symmetry was proposed by Purcell and Ramsey. The Standard Model predicts that a value of the e-EDM |d e,SM | < 10-38 e.cm that is beyond the reach of current experiment. At the same time, theories beyond the Standard Model predict an e-EDM at or near the current experimental level of |d e,exp | < 1.3 × 10-27 e.cm. Thus an e-EDM is a great place look for physics beyond the Standard Model. The existence of a permanent electric dipole moment would break the usual degeneracy between states of a molecule that only differ by the sign of the projection of their total angular momentum onto the axis of an external electric field. Heavy polar diatomic molecules are expected to be particularly sensitive to an e-EDM. Among the many proposed e-EDM molecules, the PbF molecule may be uniquely sensitive to an e-EDM because the magnetic moment of its ground state vanishes at a magic value of external electric field 67 kV/cm). This thesis reports on the creation of a stable molecular beam source of PbF based on the serendipitous discovery of the reaction of lead vapor and MgF2 . This thesis also gives the result of the following achievements enabled by this source: (1) The first demonstration of resonant enhanced multiphoton ionization(REMPI) detection of the molecule. (2) Experimental measurement and analysis of the rotational spectra of the 0-0 band of the B ← X1 transition of PbF. This measurement determines the rotational temperature of our source. (3) Measurement of appearance ionization from the B and D states of the PbF molecule. This measurement improves the known ionization potential of PbF from 7.5 ± 0.3 eV to 7.54 ± 0.01 eV, (4) Achievement of a multiphoton ionization probe of PbF that is doubly resonant with the A ← X1 and D ← A transitions. This scheme allows for fully state resolved spectra of the molecule. (5) Direct measurement of the lifetime of the PbF molecule. (6) Measurement of hyperfine constants that model the interaction of the unpaired electron in 208Pb19F with the 19F nucleus. In addition to these achievements, a new type of ultra-sensitive REMPI is reported. Whereas conventional REMPI is typically carried out with pulsed laser systems, this new technique, dubbed pc-REMPI, occurs with a combination of continuous and pseudo-continuous lasers. This technique improves the detection sensitivity of the original PbF REMPI probe by a factor of 100. At the same time, the technique improves the spectra linewidth from 2 GHz to 90 MHz, allowing for full resolution of the hyperfine structure of the molecule.
- M.Sc in Physics , University of Oklahoma, USA
- B.Sc in Physics with a minor in Computer Science, University of Peradeniya, Sri Lanka
- Engineers to Software Technology, TATA INFOTECH Education, Sri Lanka
- Information Technology Professionals, Australian Computer Society (ACS), Australia
Graduate Students
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Holland, Torrey
-Lecture in School of Physics and Applied Physics, Southern Illinois University Carbondale (SIUC) Show more
Coming Soon...- M.Sc. in Physics, SIUC
- B.Sc. in Physics
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Mandrell, Christopher
-Ph.D. Student in Applied Physics PhD Program, Southern Illinois University Carbondale (SIUC) Show more
Coming Soon...- M.Sc. in Physics, SIUC
- B.Sc. in Physics and Math, SIUC
- Associates of Pre-Engineering, John A. Logan College
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Robinson, Karunanithy
-Ph.D. Student in Applied Physics PhD Program, Southern Illinois University Carbondale (SIUC) Show more
Robinson Karunanithy is a Ph.D. candidate at the School of Physics and Applied Physics, Southern Illinois University at Carbondale (SIUC). He received his bachelor's and master's degree at the University of Peradeniya in Sri Lanka. He received a master's degree in Physics at SIUC in 2020 May. Robinson is continuing his higher education in Ph.D. since 2020. His research involves the early detection of Ovarian Cancer (OC) through bioconjugation in conjunction with spectroscopy techniques. In this regard, he is using various laser-based spectroscopies such as ultrafast picosecond Laser-Induced Breakdown Spectroscopy (LIBS), Fourier-Transform Infrared (FT-IR), Surface Enhanced Raman Spectroscopy (SERS), Mass Spectroscopy (MS), and UV-Visible spectroscopy. Further, his research also concentrates on a machine learning approach on the Raman spectrum of pancreatic cancer cells to classify tumor populating cells and parental control cells. In addition, he is curious to learn about MRI/NMR, CT, PET, SPECT techniques to integrate into his research.
- M.Sc. in Physics, SIUC, 2020
- M.Sc. in Nanoscience and Nanotechnology, University of Peradeniya, Sri Lanka, 2016
- B.Sc. in Physics and Statistics, University of Peradeniya, 2013
Peer-Reviewed Journal Articles: Show more
- R. Karunanithy, T. Holland, and P. Sivakumar*, “Influence of Glutaraldehyde's Molecular Transformations on Spectroscopic Investigations of Its Conjugation with Amine-modified Fe3O4 Microparticles in the Reaction Medium”, Langmuir, 37(17), 5242-5251 (2021); doi.org/10.1021/acs.langmuir.1c00182
- T. Holland, A. M. Abdul-Munaim, C. Mandrell, R. Karunanithy , D. G. Watson, and P. Sivakumar*, “UV-Visible Spectrophotometer for Distinguishing Oxidation Time of Engine Oil”, Lubricants, 9(4), 37 (2021); doi.org/10.3390/lubricants9040037
- S. Li, T. De Silva, I. Arsano, D. Gallaba, R. Karunanithy, M. Wasala, X. Zang, P. Sivakumar, A. Migone, M. Tsige, X. Ma, and S. Talapatra, “High adsorption of benzoic acid on single walled carbon nanotube bundles”, Scientific Reports, 10, 10013 (2020); doi.org/10.1038/s41598-020-66871-4
- K. Robinson, G.R.A. Kumara, R.J.G.L.R. Kumara, E.N. Jayaweera, and R.M.G. Rajapakse, “SnO2/ZnO composite dye-sensitized solar cells with graphene-based counter electrodes”, Organic Electronics, 56, 159-162 (2018); doi.org/10.1016/j.orgel.2018.01.040
Conference Presentation: Show more
- R. Karunanithy, T. Holland, and P. Sivakumar, “Micro-particles immunoassays for early detection of ovarian cancer using laser based spectroscopy”, International Symposium on Molecular Spectroscopy (ISMS), 2020, University of Illinois Urbana Champaign; http://hdl.handle.net/2142/107621
- P. Patil, R. Karunanithy, O. Pitkanen, S. Lei, P. Sivakumar, K. Kordas, and S. Talapatra, “Electronic and optoelectronic properties of Indium Tin Selenide (In1-xSnxSe)”, Bulletin of the American Physical Society, 65, 2020; http://meetings.aps.org/Meeting/MAR20/Session/G53.8)
- R. Karunanithy, T. Holland, and P. Sivakumar, “Identifying the differences in conjugated vs. non-conjugated biomolecules in cancer research using vibrational spectroscopy”, International Symposium on Molecular Spectroscopy (ISMS), 2019, University of Illinois Urbana Champaign; https://www.ideals.illinois.edu/handle/2142/104498
- T. De Silva, C. Damery, R. Karunanithy, R. Alkhaldi, P. Patil, M. Wasala, P.Sivakumar, and S.Talapatra, "Flexible supercapacitors with vertically aligned multiwalled carbon nanotubes (MWCNT) directly synthesized on a metal foil", American Physical Society (APS), 2019; https://meetings.aps.org/Meeting/MAR19/Session/A47.14
- T. De Silva, D. Gallaba, R. Karunanithy, M. Wasala, X. Zhang, S. Li, I. Arsano, P. Sivakumar, M. Tsige, X. Ma, A. Megone, and S. Talapatra, "Synthesis and characterization of single walled carbon nanotubes (SWNT) through direct decomposition ferrocene", American Physical Society (APS), 2019; https://ui.adsabs.harvard.edu/abs/2019APS..MARB12013D/abstract
- K. Robinson, T. Holland, and P. Sivakumar, "Micro-particles Immunoassays for Early Detection of Ovarian Cancer using Laser Based Spectroscopy", April 2019, Southern Illinois University Carbondale.
- J. Jurak, R. Karunanithy, and P. Sivakumar, "Toward developing immunoassays using the HE4 biomarker to improve the early detection of epithelial ovarian cancer", June 2019, Southern Illinois University Carbondale
- A. Debnath, B. Talluri, R. Karunanithy, P. Sivakumar, P. Kohli, and F. Chowdhury, "ZnO Nanowires based Biosensor Platform for Optimizing Methanogenesis", April 2019, Southern Illinois University Carbondale.
- T.E. Holland, R. Karunanithy, A.M. Abdul-Munaim, P. Sivakumar, and D.G. Watson, “Determination of glycol contamination in engine oil by Infrared and UV-Vis spectroscopy”, International Symposium on Molecular Spectroscopy (ISMS), 2018, University of Illinois Urbana Champaign; https://www.ideals.illinois.edu/handle/2142/100760
- L. Kumara, A.W.M.V. Ekanayaka, and R. Karunanithy, “A conceptual study on developing a renewable energy-based electrical grid”, International Conference on Structural Engineering and Construction Management, 2017, 8, 81.
Interests/Hobbies: Show more
- Playing Cricket and Football (Soccer)
- Hangouts and partying with frineds
Undergraduate Students
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Jurak, Jessica
B.Sc. Candidate, Southern Illinois University Carbondale Show more
Coming Soon...