Hope College Department of Physics and Engineering
Research Experiences for Undergraduates
Summer 2003
Project Summary

 
 

Project Title: Investigating Radioactive Nuclei Beam Reactions with a Large Area Neutron Detector
Student Name: Patrick J. Mears
Studentís home institution: Hope College
Research Advisor(s): Dr. P. A. DeYoung, Dr. G. F. Peaslee
Source of Support: NSF-RUI
 

In 2002 the Hope college nuclear group completed a large area neutron detector (Neutron Wall) for use at Notre Dame's Nuclear Structure Laboratory. The neutron wall consists of eight 60" x 6" x 2", position sensitive, plastic scintillators. In 2003, two experiments were conducted in which the neutron wall was used to detected neutrons in coincidence with other reaction products. In one experiment, a 26MeV 6He beam impacted a CH2 target to form 7Li*. The purpose was to investigate the structure of 7He. Rather than attempting to make 7He, the goal of this experiment was to populate the T=3/2 excited 7Li isobaric analog states of 7He. 7Li* was used because 7He has a 3x10^-21 second lifetime and is extremely difficult to obtain and use in experiments. The other experiment studied the 6He + 209Bi reaction at a beam energy of 23MeV. The halo nucleus of 6He consists of an alpha core with a two neutron "skin" that is much more loosely bond than the rest of the nucleus. In a previous experiment1 with 6He + 209Bi a large alpha cross section was observed. This experiment was done to further investigate 6He reactions with a focus on projectile breakup. When breakup occurs both neutrons are released from the alpha core. Because the alpha particle is charged its trajectory is affected by the Coulomb repulsion from the 209Bi nuclei. The trajectory of the neutrons, however, will be straight once they are released from the alpha core. The alpha particles were detected using two E-DE Si detectors and the neutrons were detecting using the neutron wall. After the experiment, events in which neutrons and alphas were detected in coincidence were identified. Neutron position and energy calibrations have been done. The next step is to look at the angular distribution of neutrons in the wall in an attempt to determine the cross section of 6He breakup in this experiment. Work with data from both experiments is being continued. 1E.F. Aguilera, et al. Phys. Rev. Lett. 84, 5058 (2000).

Slide show of Patrick Mear's work (Requires Microsoft PowerPoint or a PowerPoint viewer.)
__________________________________________________________________________________________________________________________________________________________ Publications and Presentations:
“Comparison of Glass Fragments Using Particle Induced X-Ray Emission (PIXE) Spectrometry.” P.A. DeYoung, P.J. Mears*, C.C. Hall*, D.J. Padilla*, R.A. Sampson*, and G.F. Peaslee. Scheduled for publication in the Journal of Forensic Sciences, (2011).
“Forensic Analysis of Tempered Sheet Glass by Particle Induced X Ray Emission (PIXE)” L. J. Jisonna, P. A. DeYoung, J. Ferens*, C. Hall*, J. M. Lunderberg*, P. Mears*, D. Padilla*, G. F. Peaslee, and R. Sampson*. Nucl. Instr. And Meth. B, Nucl. Instr. And Meth. B (2011).
“Hindrance of Complete Fusion in the 8Li+208Pb System at Above-Barrier Energies.” E.F. Aguilera, E. Martinez-Quiroz, P. Rosales, J.J. Kolata, P.A. DeYoung, P.J. Mears*, C. Guess*, F.D. Becchetti, J.H. Lupton, and Yu Chen. Phys. Rev. C 80, 044605 (2009).
“Proton-halo effects in the 8B+58Ni reaction near the Coulomb barrier.” E.F. Aguilera, E. Martinez-Quiroz, P. Rosales, D. Lizcano, A. Gomez-Camacho, J.J. Kolata, L.O. Lamm, V. Guimaraes, R. Lichtenthaler, O. Camargo, F.D. Becchtti, H. Jing, P.A. DeYoung, P.J. Mears*, and T.L. Belyaeva. Revista Mexicana de Fisica 55, 1 (2009).
“Reaction Cross Sections for 8B, 7Be, and 6Li+58Ni Near the Coulomb Barrier: Proton-halo Effects.” E.F. Aguilera, E. Martinez-Quiroz, D. Lizcano, A. Gomez-Camacho, J.J. Kolata, L.O. Lamm, V. Guimaraes, R. Lichtenthaler, O. Camargo, F.D. Becchetti, H. Jiang, P.A. DeYoung, P,.J. Mears*, and T.L. Belyaeva. Phys. Rev. C 79, 021601(R) (2009).
“Development of an Ion Beam Analysis Method for Forensic Analysis of Glass.” Richard Sampson*, Graham F. Peaslee, Paul A. DeYoung, Christopher Hall*, Derek Padilla*, and Patrick Mears*. American Academy of Forensic Sciences 2008 Annual Meeting, Washington D.C. 2008.
“Neutron-Decay Spectroscopy of Neutron-Rich Oxygen Isotopes.” M.Thoennessen, C.R. Hoffman, T. Baumann, D. Bazin, J. Brown, G. Christian, P.A. DeYoung, J.E. Finck, N. Frank, J. Hinnefeld, R.Howes, P. Mears*, E.Mosby, S. Mosby, J. Reith*, B. Rizzo*, W.F. Rogers, G. Peaslee, W.A. Peters, A. Schiller, M.J. Scott, S.L. Tabor, P.J. Voss, and T. Williams. ENAM08, book of abstracts page 30, (2008).
“Elastic Scattering of a Proton-Halo Nucleus: 8B+58Ni.” E.F. Aguilera, E. Martinez-Quiroz, P. Rosales, D. Lizcano, A. Gomez-Comacho, J.J. Kolata, L.O. Lamm, V. Guimaraes, R. Lichtenthaler, O. Camargo, F.D. Becchetti, H. Jiang, P.A. DeYoung, and P.J. Mears*. Revista Mexicana de Fisica 54, 1 (2008).
"Determination of the N = 16 shell closure at the oxygen drip line." C.R. Hoffman, T. Baumann, D. Bazin, J. Brown, G. Christian, P.A. DeYoung, J.E. Finck, N. Frank, J. Hinnefeld, R. Howes, P. Mears*, E. Mosby*, S. Mosby*, J. Reith*, B. Rizzo*, W.F. Rogers, G. Peaslee, W.A. Peters, A. Schiller, M.J. Scott*, S.L. Tabor, M. Thoennessen, P.J. Voss*, and T. Williams. Phys. Rev. Lett. 100, 152502 (2008).
"Breakup of 6He Incident on 209Bi near the Coulomb Barrier." J.J. Kolata, H. Amro, F.D. Becchetti, J.A. Brown, P.A. DeYoung, M. Hencheck, J.D. Hinnefeld, G.F. Peaslee, A.S. Fritsch, C. Hall*, U. Khadka*, Patrick J. Mears*, P. O’Rourke, D. Padilla*, J. Reith*, Tabatha Spencer, and T. Williams. Phys. Rev. C 75, 031302 (2007).
"7Be-Induced alpha-Transfer Reaction on 12C." H. Amro, F.D. Becchetti, Yu Chen, Hao Jiang, M. Ojaruega, M.J. Golobish, H.C. Griffin, J.J. Kolata, B. Skorodumov, G. Peaslee, P.A. DeYoung, P. Mears*, D. Denby*, J. Brown, J.D. Hinnefeld, and A.M. Moro. Euro. Phys. Jour. 150, 1 (2007).
“Elastic Scattering of for the System 7Be+58Ni at Energies Near the coulomb Barrier.” D. Lizcano, EF. Aguilera, H. Garcia0-Martinez, E. Martinez-Quiroz, J.J. Kolata, H.A. Amro, L.O. Lamm, H. jiang, F.D. Becchetti, V. Guimaraes, R. Lichtenthaler, O. Camargo, P.A. DeYoung, and P.J. Mears*. XXIX Symposium on Nuclear Physics. Cocoyoc, Mexico, January 3-6, 2006.
“Elastic Scattering of 6Li on 58>Ni at Engeries Around the Coulomb Barrier.” H. Garcia-Martinez, E.F. Aguilera, D. Lizcano, E. Martinez-Quiroz, J.J. Kolata, H.A. Amro, L.O. Lamm, H. Jiang, F.D. Becchetti, V. Guimaraes, R. Lichtenhaler, O. Camargo, P.A. DeYoung, and P.J. Mears*. XXIX Symposium on Nuclear Physics. Cocoyoc, Mexico, January 3-6, 2006.
"Protons from 8B+58Ni." E.f. Aguilera, E. Martinez-Quiroz, H. Garcia-martinez, D. Lizcano, J.J. Kolato, L.O. Lamm, G. Rogachev, P.A. DeYoung, C. Guess*, U. Khadka*, P.J. Mears*, F.D. Becchetti, Y. Chen, H. Jiang, J.D. Hinnefeld, and G.F. Peaslee. Revista Mexicana de Fisica 52, 41 (2006).
“Two-neutron Transfer in the 6He + 209Bi Reaction Near the Coulomb Barrier.” Patrick J. Mears*, P.A. DeYoung, G.F. Peaslee, J.J. Kolata, E.F. Aguilera, and F.D. Becchetti. Poster FR.00067. 2nd Joint Meeting of the Nuclear Physics Division of the APS and The Physical Society of Japan. Maui HI September 2005.
"Two-neutron Transfer in the 6He+209Bi Reaction Near the Coulomb Barrier." P.A. DeYoung, P.J. Mears*, J.J. Kolata, E.F. Aguilera, F.D. Beccetti, Y. Chen, M. Cloughesy, H. Griffin, C. Guess*, J.D. Hinnefeld, H. Jiang, Scott R. Jones, U. Khadka*, D. Lizcano, E. Martinez-Quiroz, M. Ojaniega, G.F. Peaslee, A. Peña*, S. VanDenDrieddshe, and J. Zimmerman. Phys. Rev. C 71, 051601 (2005).
“Structure of Heavy Helium Isotopes via the Isobaric Analog States in Lithium.” G.V. Rogachev, A. Aprahamian, P. Boutachkov, M. Quinn, J.J. Kolata, B. Skorodumov, A. Woehr, V.Z. Goldberg, G. Chubarian, A. Fomichev, M.S. Golovkiv, Yu.Ts. Oganessian, A. Rodin, R.S. Slepnev, G. Ter-Akopian, R. Wolski, W.H. Trzaska, D.V. Aleksandrov, P.A. DeYoung, G.F. Peaslee, P.J. Mears*, F.D. Becchetti, and Y. Chen. Paper CE.006. Division of Nuclear Physics Fall Meeting. Tucson, AZ, October 2003.