Hope College Department of Physics and Engineering
Research Experiences for Undergraduates
Summer 2001
Project Summary

Project Title: Measuring spatial extent of 18Fl
Student Name: Ben Hilldore
Studentís home institution: Hope College
Research Advisor(s): Dr. Paul DeYoung
Source of Support (NSF-REU, or other): NSF-RUI

The first of my two projects was to design a data analysis shell based on the IDL programming language. IDL is an array optimized programming language with emphasis on graphical data manipulation. The package I wrote includes one-dimensional histogram plotting and gating, two-dimensional density plotting and gating, integration of peaks/regions, and complex condition gates and pseudo-parameters.

My second project was to use this data analysis package I wrote to analyze the data from an experiment performed in January 2001 by Dr. Robert Warner. The specific goal of the experiment is to measure the total reaction cross-section of 18F and 18mF in order to better understand the particular sizes of these nuclei. Since a large cross-section implies a large spatial extent, the cross-sections of 18F and 18mF will be used to determine if excited nuclei have a larger spatial extent than the corresponding ground state species. In performing this experiment, a beam of 416MeV 17O was incident on C or Pb targets. The resulting secondary nuclei, including 18F, were then sent through an analyzing spectrometer to select all ions with the same magnetic rigidity. The resulting nuclei were directed onto a stack of silicon detectors. This stack consists of one position sensitive detector and three energy detectors. Based on energy deposited in each silicon detector, the species of ion can be determined for that event. With the species separated, analysis of each species can be done.

Preliminary Results:

Reaction cross-section was found based on the following formula:

where s is the areal density of detector/target.

for 18Fl

for 18Fl

Statistical error was found to be less than 3%. The systematic error associated with integrating was large. Though these results are not precise, they give us a place to start when pursuing more precise methods of analysis.

 In conclusion, more work needs to be done on both IDL and on the analysis of the 18Fl experiment. The analysis package needs to have the ability to integrate, calculate centroids, and manipulate plot parameters implemented. The next goal of the 18Fl experiment will be to determine and implement a new method for separating the reacted from the non-reacted species.

I would like to thank the NSF for providing funding for research, Dr. Paul DeYoung for making this research possible for me and providing me with many useful insights, Dr. Robert Warner for performing the 18Fl experiment and providing help with the analysis, and to Hope College for providing the undergraduate research opportunity to me.

Slide show of Ben Hilldore's work

Publications and Presentations:
“The (8Li, α) reaction at Low Energy: Direct 4H Cluster Transfer?” F.D. Becchetti, R.S. Raymond, D.A. Roberts, J. Lucido, P.A. DeYoung, B. Hilldore*, J. Bychowski*, A.J. Huisman*, P.J. VanWylen*, J.J. Kolata, G. Rogachev, and J.D. Hinnefeld. Phys. Rev. C 71, 054610 (2005).
209Bi(6He,α) Reaction Mechanisms Studied Near the Coulomb Barrier Using n-α Coincidence Measurements.” J.P. Bychowski*, P.A. DeYoung, BB. Hilldore*, J.D. Hinnefeld, A. Vida*, F.D. Becchetti, J. Lupton, T.W. O’Donnell, J.J. Kolata, G. Rogachev, and M. Hencheck. Phys. Lett. 596B, 26 (2004).
“Study of the (8Li,α) Reaction at Low Energy: Direct 4H Transfer?” F.D. Becchetti, D.A. Roberts, J. Lucido, P.A. DeYoung, B. Hilldore*, J. Bychowski*, J.J. Kolata, and G. Rocharchev. The Sixth International Conference on Radioactive Nuclear Beams, Argonne, Il, September 2003.
“Analysis of Event-Mode Data with Interactive Data Language.” P.A. DeYoung, B.B. Hilldore*, L.M. Kiessel*, and G.F. Peaslee. Nucl. Instr. and Meth. A 505, 294 (2003).
“Coulomb Excitation of Giant Resonances with Heavy Ion Projectiles.” B.B. Hilldore*, B. Atallah*, P.A. DeYoung, L.Kiessel*, M.K. MacDermaid*, G.F. Peaslee, D. Bazin, K. Govaert, B. Sherrill, M. Thoennessen, J. Beene, B. Blank, M. Chartier, F. Liang, R. Varner. Paper 5P1.073. Division of Nuclear Physics Fall Meeting. East Lansing, MI, October 2002.
“Understanding the 209Bi(6He,4He) Reaction Mechanisms Near the Coulomb Barrier.” J.P. Bychowski*, P.A. DeYoung, B.B. Hilldore*, J.D. Hinnefeld, A. Vida, F.D. Becchetti, J. Lupton, T.W. O’Donnel, J.J. Kolata, G. Rogachev, and M. Hencheck. Paper 5P1.072. Division of Nuclear Physics Fall Meeting. East Lansing, MI, October 2002.
“Analysis of Event-Mode Data with Interactive Date Language.” P.A. DeYoung, B.B. Hilldore*, L.M. Kiessel*, and G.F. Peaslee. 2002 Symposium on Radiation Measurements and Applications, University of Michigan, April 2002.
“Sizes of Nuclei.” Benjamin Hilldore*, and P.A. DeYoung. PEW Midstates Consortium Undergraduate Research Symposium, University of Chicago, November 2001.