skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: The astrophysical reaction rate for the {sup 18}F(p,{alpha}){sup 15}O reaction

Abstract

Proton and alpha widths for a 3/2{sup +} ({ell}{sub p} = 0) state in {sup 19}Ne at E{sub x} = 7.1 MeV have been extracted using the results of recent measurements of the {sup 18}F(p,{alpha}){sup 15}O reaction. This {ell}{sub p} = 0 resonance dominates the astrophysical reaction rates at temperatures T{sub 9} > 0.5.

Authors:
 [1];  [2];  [3]
  1. Argonne National Lab., IL (United States)
  2. Hebrew Univ., Jerusalem (Israel)
  3. Wisconsin Univ., Madison, WI (United States) [and others
Publication Date:
Research Org.:
Argonne National Lab., IL (United States)
Sponsoring Org.:
USDOE, Washington, DC (United States)
OSTI Identifier:
212427
Report Number(s):
ANL/PHY/PP-86895
ON: DE96007467; TRN: 96:012139
DOE Contract Number:
W-31109-ENG-38
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: [1996]
Country of Publication:
United States
Language:
English
Subject:
66 PHYSICS; FLUORINE 18 TARGET; PROTON REACTIONS; OXYGEN 15; ISOTOPE PRODUCTION; NEON 19; OXYGEN 15 TARGET; ALPHA REACTIONS; RADIOACTIVE ION BEAMS; NUCLEOSYNTHESIS; ALPHA PARTICLES; ASTROPHYSICS

Citation Formats

Rehm, K.E., Paul, M., and Roberts, A.D.. The astrophysical reaction rate for the {sup 18}F(p,{alpha}){sup 15}O reaction. United States: N. p., 1996. Web. doi:10.2172/212427.
Rehm, K.E., Paul, M., & Roberts, A.D.. The astrophysical reaction rate for the {sup 18}F(p,{alpha}){sup 15}O reaction. United States. doi:10.2172/212427.
Rehm, K.E., Paul, M., and Roberts, A.D.. Fri . "The astrophysical reaction rate for the {sup 18}F(p,{alpha}){sup 15}O reaction". United States. doi:10.2172/212427. https://www.osti.gov/servlets/purl/212427.
@article{osti_212427,
title = {The astrophysical reaction rate for the {sup 18}F(p,{alpha}){sup 15}O reaction},
author = {Rehm, K.E. and Paul, M. and Roberts, A.D.},
abstractNote = {Proton and alpha widths for a 3/2{sup +} ({ell}{sub p} = 0) state in {sup 19}Ne at E{sub x} = 7.1 MeV have been extracted using the results of recent measurements of the {sup 18}F(p,{alpha}){sup 15}O reaction. This {ell}{sub p} = 0 resonance dominates the astrophysical reaction rates at temperatures T{sub 9} > 0.5.},
doi = {10.2172/212427},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Fri Mar 01 00:00:00 EST 1996},
month = {Fri Mar 01 00:00:00 EST 1996}
}

Technical Report:

Save / Share:
  • An excitation function for the {sup 18}F({ital p},{alpha}){sup 15}O reaction has been measured in the energy range {ital E}{sub c.m.}=600{endash}800 keV using a radioactive {sup 18}F beam. A resonant state with a spin value of 3/2{sup +} has been found at an energy of 652 keV above threshold. This {ital l}{sub {ital p}}=0 resonance is found to dominate the astrophysical reaction rate at temperatures {ital T}{sub 9}{approx_gt}0.5. {copyright} {ital 1996 The American Physical Society.}
  • For the first time the {sup 18}F({ital p},{alpha}){sup 15}O reaction has been studied with a {sup 18}F beam at energies which are of interest to explosive nucleosynthesis. Utilizing the gas-filled magnet technique a clean identification of the reaction products was achieved. A resonance with spin 3/2{sup +} at an equivalent c.m. energy of 660 keV dominates the yield.
  • {sup 18}F is produced in stars during the so-called breakout from the hot CNO cycle and is important as one of the links connecting the HCNO cycle with the rp-process by producing {sup 19}Ne via the {sup 18}F(p,{gamma}) reaction. There is, however, a competing reaction {sup 18}F(p,{alpha}){sup 15}O which leads back into the CNO cycle. The importance of {sup 18}F for producing {sup 19}Ne therefore depends strongly on the (p,{gamma}) to (p,{alpha}) cross sections ratio. We have begun to study the {sup 18}F(p,{alpha}){sup 15}O reaction using a {sup 18}F beam. {sup 18}F, which is a well-studied PET isotope, is generatedmore » at the medical cyclotron of the University of Wisconsin. Aqueous [{sup 18}F] fluoride ions are produced via the {sup 18}O(p,n){sup 18}F reaction using a 30-{mu}A, 11.4-MeV proton beam bombarding a 95% enriched [{sup 18}O] water target and electroplated onto the end of a 3-mm diameter Al anode. After electroplating, the anodized Al is pressed into a copper cathode insert for the National Electrostatics Corporation SNICS ion source, transported to Argonne National Laboratory and installed in the ion source of the Tandem accelerator at ATLAS. With an activity at the end of the electroplating process of 530 mCi, the starting activity after 2 h, which is the time needed to transport and install the material in the SNICS source, was 250 mCi, corresponding to a total number of {sup 18}F atoms of 8.8 x 10{sup 13}.« less
  • The abundance of {sup 18}F in Nova explosions is an important issue for the understanding of this astrophysical phenomenon. For this reason it is necessary to study the nuclear reactions that produce or destroy this isotope in novae. Among these latter processes, the {sup 18}F(p,{alpha}){sup 15}O is one of the main {sup 18}F destruction channels. We report here on the preliminary results of the first experiment that applies the Trojan Horse Method to a Radioactive Ion Beam induced reaction. The experiment was performed using the CRIB apparatus of the Center for Nuclear Study of The Tokyo University.