Production Cross Sections of Fragments from Beams of 400{endash}650 MeV per Nucleon {sup 9}Be, {sup 11}B, {sup 12}C, {sup 14}N, {sup 15}N, {sup 16}O, {sup 20}Ne, {sup 22}Ne, {sup 56}Fe, and {sup 58}Ni Nuclei Interacting in a Liquid Hydrogen Target. II. Isotopic Cross Sections of Fragments

Journal Article · Tue Dec 01 00:00:00 EST 1998 · Astrophysical Journal

DOI:https://doi.org/10.1086/306446· OSTI ID:324910

Webber, W R ^[1]; Kish, J C; Rockstroh, J M ^[2]; Cassagnou, Y; Legrain, R; Soutoul, A; Testard, O ^[3]; Tull, C ^[4]

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1. Astronomy Department, New Mexico State University, P.O. Box 30001, Las Cruces, NM 88003 (United States)
2. Spectra Research Incorporated, Portsmouth, NH 03820 (United States)
3. Service d`Astrophysique, Cen. Saclay, CEDEX (France)
4. Lawrence Berkeley Laboratory, University of California, Berkeley, CA 94720 (United States)

We have measured the isotopic cross sections of 130 secondary fragmentation isotopes from 10 different beam nuclei from {sup 9}Be to {sup 58}Ni that were accelerated to between 400 and 650 MeV nucleon{sup {minus}1} at the SATURNE Accelerator in France in 1993 and 1994. These beam nuclei interacted in a 1.52 g cm{sup {minus}2} thick liquid hydrogen target, and the isotopic fragments were observed. This is the first use of a pure hydrogen target with a thickness approximating the amount of hydrogen traversed by cosmic rays in our Galaxy to measure cross sections. Several of the beam charges such as {sup 9}Be, {sup 11}B, {sup 15}N, and {sup 22}Ne have not had their fragmentation cross sections measured previously. The isotopic cross sections from the {sup 12}C, {sup 14}N, {sup 16}O, {sup 20}Ne, {sup 56}Fe, and {sup 58}Ni beam interactions are compared with earlier measurements by our group using a CH{sub 2} {minus} C target subtraction technique to determine the hydrogen cross sections. The overall agreement between the new measurements and the earlier measurements using a CH{sub 2} {minus} C target subtraction is excellent with a systematic consistency between measurements {approximately}3{percent}{endash}5{percent}. These new isotopic cross sections define the Galactic production of the secondary isotopes {sup 10}Be, {sup 10}B, {sup 11}B, {sup 13}C, {sup 14}N, {sup 15}N, and {sup 18}O as well as Fe and Ni secondary decay isotopes from Cl to Co to a level of precision of {approximately}3{percent}{endash}5{percent}. These cosmic-ray isotopes are important for understanding the nucleosynthesis in the cosmic-ray sources as well as tracing the detailed propagation history of cosmic rays in the Galaxy. {copyright} {ital {copyright} 1998.} {ital The American Astronomical Society}

• OSTI ID: 324910
• Journal Information: Astrophysical Journal, Vol. 508, Issue 2; Other Information: PBD: Dec 1998
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
BERYLLIUM
BORON
CARBON
NITROGEN
NEON
OXYGEN
IRON
NICKEL
COSMIC RAY PROPAGATION
COSMIC RADIATION
ISOTOPE RATIO
NUCLEOSYNTHESIS
HYDROGEN
BERYLLIUM 9
BORON 11
CARBON 12
NITROGEN ISOTOPES
NEON ISOTOPES
OXYGEN 16
IRON 56
NICKEL 58
GEV RANGE
TOTAL CROSS SECTIONS
NUCLEAR FRAGMENTATION
NUCLEAR FRAGMENTS
ATOMIC PROCESSES