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Dr. Kumar S. Sharma

Professor, Department of Physics and Astronomy, University of Manitoba

B.Sc. (Hon.), University of Manitoba, 1973
Ph.D., University of Manitoba, 1979

Research website:

Contact:

Department of Physics & Astronomy
University of Manitoba
Winnipeg, MB R3T 2N2
Canada

Phone: +1-204-474-6181
FAX: +1-204-474-7622
Email: sharma umanitoba.ca

Research interests:

The atomic masses of nuclides far from stability provide information on the energy released in the decay and nuclear reactions involving these exotic, short-lived, nuclei. The results are an important ingredient in predicting the rates and pathways of nuclear reactions that power explosive astrophysical events thought to be responsible for the nucleosynthesis of the heavier elements (through the rp-, vp- and r-processes). The data also provides a view of nuclear structure in regions where the nuclei have extreme neutron to proton ratios and, provide an opportunity for tests of nuclear physics theories trying to explain the properties of nuclei. The Canadian Penning Trap Mass Spectrometer (CPT) is being used to measure the masses of very neutron-rich isotopes on or near the expected the reaction path for the astrophysical r-process. The nuclides of interest are produced by the CARIBU (Californium Radioactive Ion Beam Upgrade) facility at the Argonne Tandem Linear Accelerator System (ATLAS) by the spontaneous fission of the atoms in a 1.7 Ci, ²⁵²Cf fission source. Improvements to the system have allowed us to perform measurements with an accuracy of (delta-m/m) of 10^-7 among nuclides approaching 10^-5% of the fission production. The implementation of a new phase-imaging measurement technique has allowed us to gain a dramatic increase in resolving power while reducing the observation time simultaneously, a significant improvement for measuring nuclides with short half-lives.

In a second ion-trap system, the ions can be trapped in a gas-filled, open-geometry, radio-frequency quadrupole, ion trap (RFQ) providing a unique opportunity to study the correlation between the beta particles and the neutrinos emitted during the decay of the trapped ions. We have been studying the A=8 system with this apparatus in tests particle physics theories of the weak interaction. This ion trap has also been used to observe the emission of beta-delayed neutrons by the trapped ions during their decay. A third dedicated RFQ trap to study the decay properties of neutron-rich nuclides is planned.

This work is carried out in collaboration with: F. Buchinger, McGill University, J. Clark and G. Savard, Physics Division, Argonne National Laboratory, Ralph Segel, Northwestern University, Nicholas Scielzo, Lawrence Livermore National Laboratory and Ani Aprahamian and Maxime Brodeur from Notre Dame University, from the USA.

Other mass measurements with trapped ions of particular interest, such as the determination of Q-values for double-beta decay, are undertaken as opportunities arise.

Employment and Educational Opportunities:

We currently have openings for:

 -    M.Sc. and Ph.D. students.
 -    Post-doctoral fellow

Inquiries are welcome.

Selected publications:

1. R. Orford, N. Vassh, J. A. Clark, G. C. McLaughlin, M. R. Mumpower, G. Savard, R. Surman, A. Aprahamian, F. Buchinger, M. T. Burkey, D. A. Gorelov, T. Y. Hirsh, J.W. Klimes, G. E. Morgan, A. Nystrom, and K. S. Sharma; “Precision Mass Measurements of Neutron-Rich Neodymium and Samarium Isotopes and Their Role in Understanding Rare-Earth Peak Formation”, Physical Review Letters 120, 262702, 6 pages, June (2018). https://doi.org/10.1103/PhysRevLett.120.262702

2. D. J. Hartley, F. G. Kondev, R. Orford, J. A. Clark, G. Savard, A. D. Ayangeakaa, S. Bottoni, F. Buchinger, M. T. Burkey, M. P. Carpenter, P. Copp, D. A. Gorelov, K. Hicks, C. R. Hoffman, C. Hu, R. V. F. Janssens, J.W. Klimes, T. Lauritsen, J. Sethi, D. Seweryniak, K. S. Sharma, H. Zhang, S. Zhu, and Y. Zhu; “Masses and β-Decay Spectroscopy of Neutron-Rich Odd-Odd ^160;162Eu Nuclei: Evidence for a Subshell Gap with Large Deformation at N = 98”, Physical Review Letters 120, 182502, 6 pages, May (2018). https://doi.org/10.1103/PhysRevLett.120.182502

3. J. M. Munson, K. Siegl, N. D. Scielzo, B. S. Alana, A. Czeszumska, G. Savard, A. Aprahamian, S. A. Caldwell, C. J. Chiara, J. A. Clark, J. P. Greene, J. Harker, S. T. Marley, G. E. Morgan, E. B. Norman, R. Orford, S. Padgett, A. Perez Galvan, K. S. Sharma, S. Y. Strauss; “Recoil-ion detection efficiency for complex decays studied using the Beta-decay Paul Trap”, Nuclear Instruments and Methods A 898, pages 60-66, May (2018). https://doi.org/10.1016/j.nima.2018.04.063

4. K. Siegl, N. D. Scielzo, A. Czeszumska, J. A. Clark, G. Savard, A. Aprahamian, S. A. Caldwell, B. S. Alan, M. T. Burkey, C. J. Chiara, J. P. Greene, J. Harker, S. T. Marley, G. E. Morgan, J. M. Munson, E. B. Norman, R. Orford, S. Padgett, A. Perez Galván, K. S. Sharma, and S. Y. Strauss; “Recoil ions from the β decay of ¹³⁴Sb confined in a Paul trap”; Phys. Rev. C 97, 035504 – Published 23 March (2018), 10 pages. https://doi-org.uml.idm.oclc.org/10.1103/PhysRevC.97.035504

5. T.Y. Hirsh, A. Pérez Gálvan, M.T. Burkey, A. Aprahamian, F. Buchinger, S. Caldwell, J.A. Clark, A.T. Gallant, E. Heckmaier, A.F. Levand, S.T. Marley, G.E. Morgan, A. Nystrom, R. Orford, G. Savard, N.D. Scielzo, R. Segel, K.S. Sharma, K. Siegl, B.S. Wang; “The use of cosmic-ray muons in the energy calibration of the Beta-decay Paul Trap silicon-detector array”, Nuclear Instruments and Methods in Physics Research, A 887, p. 122–127, January (2018)

6. R. Orford, J.A. Clark, A. Nystrom, G. Savard, A. Aprahamian, M. Brodeur, F. Buchinger, D. Burdette, M.T. Burkey, T. Hirsh, J. Kelly, D. Lascar, L. Ling-Ying, G.E. Morgan, K.S. Sharma, and K. Siegl; “Phase-imaging mass measurements with the Canadian Penning Trap mass spectrometer”, Proc. 14th Int. Symp. On Nuclei in the Cosmos (NIC2016), JPS Conf. Proc. 14, 011102 (February, 2017), https://doi.org/10.7566/JPSCP.14.011102, 4 pages.

7. G. Li, S. Caldwell, J.A. Clark, S. Gulick, A. Hecht, D.D. Lascar, T. Levand, G. Morgan, R. Orford, G. Savard, K.S. Sharma, J. Van Schelt; “A compact cryogenic pump”, Cryogenics, Volume 75, April 2016, Pages 35-37 (2016)

8. T.Y. Hirsh, N. Paul, M. Burkey, A. Aprahamian, F. Buchinger, S. Caldwell, J.A. Clark, A.F. Levand, L.L. Ying, S.T. Marley, G.E. Morgan, A. Nystrom, R. Orford, A. Perez-Galvan, J. Rohrer, G. Savard, K.S. Sharma, and K. Siegl; “First operation and mass separation with the CARIBU MR-TOF”, Nuclear Instruments and Methods B, Nuclear Instruments and Methods B, 376 (2016) p. 229–232; January 2016. http://dx.doi.org/10.1016/j.nimb.2015.12.037

9. M. G. Sternberg, R. Segel, N. D. Scielzo, G. Savard, J. A. Clark, P. F. Bertone, F. Buchinger, M. Burkey, S. Caldwell, A. Chaudhuri, J. E. Crawford, C. M. Deibel, J. Greene, S. Gulick, D. Lascar, A.F. Levand, G. Li, A. Perez Galvan, K. S. Sharma, J. Van Schelt, R. M. Yee, and B. J. Zabransky; “Limit on tensor currents from ⁸Li beta decay”, Phys. Rev. Lett. 115, 182501; October(2015)

10. G. Audi, K. Blaum, M. Block, G. Bollen, S. Goriely, J.C. Hardy, F. Herfurth, F.G. Kondev, H.-J. Kluge, D. Lunney, J.M. Pearson, G. Savard, K.S. Sharma, M. Wang, Y.H. Zhang; “Comment on “Atomic mass compilation 2012” by B. Pfeiffer, K. Venkataramaniah, U. Czok, C. Scheidenberger”, Atomic Data and Nuclear Data Tables, Volumes 103–104, May–July 2015, Pages 1–3 (2015)

11. N.D. Scielzo, R.M. Yee, P.F. Bertone, F. Buchinger, S.A. Caldwell, J.A. Clark, A. Czeszumska, C.M. Deibel, J.P. Greene, S. Gulick, D. Lascar, A.F. Levand, G. Li, E.B. Norman, S. Padgett, M. Pedretti, A. Perez Galvan, G. Savard, R.E. Segel, K.S. Sharma, M.G. Sternberg, J. Van Schelt, and B.J. Zabransky; “A Novel Approach to Beta-delayed Neutron Spectroscopy Using the Beta-decay Paul Trap”, Nuclear Data Sheets 120, p 70-73, September, 2014.

12. K.S. Sharma; “Mass Spectrometry – the early years”; accepted by Int. J. Mass Spectrom. 349, p3-8;September (2013).

13. J. Van Schelt, D. Lascar, G. Savard, J. A. Clark, P. F. Bertone, S. Caldwell, A. Chaudhuri, A.F. Levand, G. Li, G. E. Morgan, R. Orford, R. E. Segel, K. S. Sharma, and M. G. Sternberg; ” First Results from the CARIBU Facility: Mass Measurements on the r-Process Path”,Phys. Rev. Lett. 111, 061102; August 2013.

14. R. M. Yee, N. D. Scielzo, P. F. Bertone, F. Buchinger, S. Caldwell, J. A. Clark, C. M. Deibel, J. Fallis, J. P. Greene, S. Gulick, D. Lascar, A. F. Levand, G. Li, E. B. Norman, M. Pedretti, G. Savard, R. E. Segel, K. S. Sharma, M. G. Sternberg, J. Van Schelt, and B. J. Zabransky; “β-delayed neutron spectroscopy using trapped radioactive ions”; Phys. Rev. Lett. 110, 092501, 2013.

15. N.D. Scielzo, G.Li, M.G. Sternberg, G. Savard, P.F. Bertone, F. Buchinger, S. Caldwell, J.A. Clark, J. Crawford, C.M. Deibel, J. Fallis, J.P. Greene, S. Gulick, A.A. Hecht, D. Lascar, J.K.P. Lee, A.F. Levand, M. Pedretti, R.E. Segel, H. Sharma, K.S. Sharma, I. Tanihata, J. Van Schelt, R.M. Yee, B.J. Zabransky, “The Beta-decay Paul trap: A radio frequency quadrupole ion trap for precision β-decay studies”; NIM A 681, p94-100, 2012.

16. J. Van Schelt, D. Lascar, G. Savard, J. A. Clark, S. Caldwell, A. Chaudhuri, J. Fallis, J. P. Greene, A. F. Levand, G. Li, K. S. Sharma, M. G. Sternberg, T. Sun, and B. J. Zabransky, “Mass measurements near the r-process path using the Canadian Penning Trap mass spectrometer”; Phys. Rev. C 85, 045805, 2012.

17. J. Fallis, J. A. Clark, K. S. Sharma, G. Savard, F. Buchinger, S. Caldwell, J. E. Crawford, C. M. Deibel, S. Gulick, A. A. Hecht, D. Lascar, J. K.P. Lee, A. F. Levand, G. Li, B. F. Lundgren, A. Parikh, S. Russell, M. Scholte-van de Vorst, N. D. Scielzo, R. E. Segel, S. Sinha, H. Sharma, M. Sternberg, T. Sun, I. Tanihata, J. Van Schelt, J. C.Wang, Y.Wang, C.Wrede, and Z. Zhou, “Mass measurements of isotopes of Nb, Mo, Tc, Ru, and Rh along the p- and rp-process paths using the Canadian Penning Trap mass spectrometer”, Phys. Rev. C 84, 045807 2011.