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Title: DIFFERENTIAL DISTRIBUTIONS OF NEUTRONS IN INELASTIC $pi$$sup -$p INTERACTIONS AT 374, 417, AND 454 Mev (thesis)

Abstract

The inelastic interactions of negative pi mesons with protons at 374, 417, and 454 Mev incident pi kinetic energy are studied by measuring the differential distributions of finalstate neutrons. The pi source is an internal target of the Berkeley 184-inch synchrocyclotron. A magnetic beamtransport system momentum-anaiyzes and focuses the pi beam at a liquid hydrogen target located in an adjacent shielded experimental area. The time-of- flight distribution of neutral particles is measured at various laboratorysystem angles between 10 and 65 deg. Neutral particles are detected by observing the charged products of their interactions in plastic scintillator. The time-of- flight information is determined electronically by time-to-height conversion and pulse-height analysis. The time resolution of the total system is 1.0 nsec. Detected neutral particles accompanied by charged particles are separated by the electronic system from those not accompanied by charged particles. Analysis presuming the principal inelastic reactions to be pi /sup -/p yields pi /sup +/ pi /sup -/n and pi /sup -/p yields pi /sup 0/ pi /sup 0/n separates the time-of-flight spectra into gamma rays, neutrons from the reaction pi /sup -/p yields pi /sup 0/n, and inelastic neutrons. Calculated values of the neutron- detection efficiency are used in themore » conversion of the neutron time-of-flight distribution to neutron differential distributions as a function of energy. A description of the neutron efficiency calculation is included. A definite deviation from the behavior expected on the basis of a statistical distribution or a simple peripheral collision model is observed in the distributions of the inelastic neutrons. The inelastic neutron differential distributions showed a strong prefurence for neutrons of low cm momentum. By integrating the differential distributions, the total cross sections for the two inelastic reactions listed above were obtained. The cross section for the pi /sup +/ pi / sup -/n channel was a rapidly rising function of incident pi energy, whereas the cross section for the pi /sup 0/ pi /sup 0/n channel was essentially constant as a function of energy. In addition, the total cross section for the processes pi /sup -/p yields neutrals was obtained along with tentative data on the angular distribution of the reaction pi /sup -/p yields pi /sup 0/n. (46 references) (auth)« less

Authors:
Publication Date:
Research Org.:
California Univ., Berkeley, CA (US). Lawrence Radiation Lab.
OSTI Identifier:
4733607
Report Number(s):
UCRL-10564
NSA Number:
NSA-17-009205
DOE Contract Number:
W-7405-ENG-48
Resource Type:
Technical Report
Resource Relation:
Other Information: Orig. Receipt Date: 31-DEC-63
Country of Publication:
United States
Language:
English
Subject:
PHYSICS; AIR; BERKELEY SYNCHROCYCLOTRON; CYCLOTRONS; ELECTRON BEAMS; IONIZATION; IRRADIATION; ORGANIC COMPOUNDS; PLANNING; SAMPLING; SCATTERING; SYNCHROTRONS; VACUUM

Citation Formats

Kurz, R.J. DIFFERENTIAL DISTRIBUTIONS OF NEUTRONS IN INELASTIC $pi$$sup -$p INTERACTIONS AT 374, 417, AND 454 Mev (thesis). United States: N. p., 1962. Web. doi:10.2172/4733607.
Kurz, R.J. DIFFERENTIAL DISTRIBUTIONS OF NEUTRONS IN INELASTIC $pi$$sup -$p INTERACTIONS AT 374, 417, AND 454 Mev (thesis). United States. doi:10.2172/4733607.
Kurz, R.J. Thu . "DIFFERENTIAL DISTRIBUTIONS OF NEUTRONS IN INELASTIC $pi$$sup -$p INTERACTIONS AT 374, 417, AND 454 Mev (thesis)". United States. doi:10.2172/4733607. https://www.osti.gov/servlets/purl/4733607.
@article{osti_4733607,
title = {DIFFERENTIAL DISTRIBUTIONS OF NEUTRONS IN INELASTIC $pi$$sup -$p INTERACTIONS AT 374, 417, AND 454 Mev (thesis)},
author = {Kurz, R.J.},
abstractNote = {The inelastic interactions of negative pi mesons with protons at 374, 417, and 454 Mev incident pi kinetic energy are studied by measuring the differential distributions of finalstate neutrons. The pi source is an internal target of the Berkeley 184-inch synchrocyclotron. A magnetic beamtransport system momentum-anaiyzes and focuses the pi beam at a liquid hydrogen target located in an adjacent shielded experimental area. The time-of- flight distribution of neutral particles is measured at various laboratorysystem angles between 10 and 65 deg. Neutral particles are detected by observing the charged products of their interactions in plastic scintillator. The time-of- flight information is determined electronically by time-to-height conversion and pulse-height analysis. The time resolution of the total system is 1.0 nsec. Detected neutral particles accompanied by charged particles are separated by the electronic system from those not accompanied by charged particles. Analysis presuming the principal inelastic reactions to be pi /sup -/p yields pi /sup +/ pi /sup -/n and pi /sup -/p yields pi /sup 0/ pi /sup 0/n separates the time-of-flight spectra into gamma rays, neutrons from the reaction pi /sup -/p yields pi /sup 0/n, and inelastic neutrons. Calculated values of the neutron- detection efficiency are used in the conversion of the neutron time-of-flight distribution to neutron differential distributions as a function of energy. A description of the neutron efficiency calculation is included. A definite deviation from the behavior expected on the basis of a statistical distribution or a simple peripheral collision model is observed in the distributions of the inelastic neutrons. The inelastic neutron differential distributions showed a strong prefurence for neutrons of low cm momentum. By integrating the differential distributions, the total cross sections for the two inelastic reactions listed above were obtained. The cross section for the pi /sup +/ pi / sup -/n channel was a rapidly rising function of incident pi energy, whereas the cross section for the pi /sup 0/ pi /sup 0/n channel was essentially constant as a function of energy. In addition, the total cross section for the processes pi /sup -/p yields neutrals was obtained along with tentative data on the angular distribution of the reaction pi /sup -/p yields pi /sup 0/n. (46 references) (auth)},
doi = {10.2172/4733607},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Thu Nov 15 00:00:00 EST 1962},
month = {Thu Nov 15 00:00:00 EST 1962}
}

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