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Compton Scattering from the Deuteron at Low Energies

Lundin, Magnus LU (2002)
Abstract (Swedish)
Popular Abstract in Swedish

Vid Compton spridning sprids fotonen elastiskt, dvs. utan att förlora energi, mot en annan partikel eller kärna. Kärnorna som användes i detta försök består av en proton och en neutron (sk. deuterium, eller tungt väte). Kärnorna bestrålades med fotoner av kända energier och de spridda fotonerna detekterades mha. stora NaI-detektorer som var placerade i olika vinklar runt strålmålet. Försöket utfördes under 8 veckor och genom att räkna antalet fotoner som kärnorna bestålades med och antalet spridda fotoner i de olika detektorerna, kan sannolikheten för att en foton skall spridas bestämmas.



Denna sannolikhet jämfördes med en teoretisk modell som beskriver sannolikheten för att en... (More)
Popular Abstract in Swedish

Vid Compton spridning sprids fotonen elastiskt, dvs. utan att förlora energi, mot en annan partikel eller kärna. Kärnorna som användes i detta försök består av en proton och en neutron (sk. deuterium, eller tungt väte). Kärnorna bestrålades med fotoner av kända energier och de spridda fotonerna detekterades mha. stora NaI-detektorer som var placerade i olika vinklar runt strålmålet. Försöket utfördes under 8 veckor och genom att räkna antalet fotoner som kärnorna bestålades med och antalet spridda fotoner i de olika detektorerna, kan sannolikheten för att en foton skall spridas bestämmas.



Denna sannolikhet jämfördes med en teoretisk modell som beskriver sannolikheten för att en foton skall spridas elastiskt mot en deuterium-kärna. Eftersom protonen och neutronen består av kvarkar, vilka har en elektrisk laddning, kommer dessa att sträckas ut då de utsätts för ett elektriskt fält (fotonen), dvs. de polariseras. Värdet (sannolikheten) som den teoretiska modellen ger, beror på polariserbarheten hos protonen och neutronen i deuterium. Genom att beräkna sannolikheten för fotonspridning för olika värden av polariserbarheterna, kan man se vilket värde som ger bäst överensstämmelse mellan modellen och experimentella data. Det är speciellt neutronens polariserbarhet som är av intresse, och denna kunde bestämmas i detta arbete. (Less)
Abstract
A series of three Compton scattering experiments on deuterium have been performed at the high-resolution tagged-photon facility MAX-lab located in Lund, Sweden. The 50 < Eg < 70 MeV tagged photons were scattered from a liquid deuterium target and detected simultaneously in three (10"x10") NaI detectors. The average laboratory angles investigated were 45, 125 and 135 deg. The influence of the inelastic contribution was minimized by implementing a narrow elastic fit-region in the missing energy spectra. Absolute cross sections were extracted for average photon energies of 55 and 66 MeV at each angle and for each experiment. The extracted cross sections are in good agreement with those measured at Illinois by Lucas et al.

... (More)
A series of three Compton scattering experiments on deuterium have been performed at the high-resolution tagged-photon facility MAX-lab located in Lund, Sweden. The 50 < Eg < 70 MeV tagged photons were scattered from a liquid deuterium target and detected simultaneously in three (10"x10") NaI detectors. The average laboratory angles investigated were 45, 125 and 135 deg. The influence of the inelastic contribution was minimized by implementing a narrow elastic fit-region in the missing energy spectra. Absolute cross sections were extracted for average photon energies of 55 and 66 MeV at each angle and for each experiment. The extracted cross sections are in good agreement with those measured at Illinois by Lucas et al.



The difference between the electric and magnetic isospin-averaged polarizabilities of the nucleon inside the deuteron, was varied within the calculations of Levchuk and L'vov to best reproduce the data, holding the sum fixed at 14.6 (10-4 fm3). The result implies that the electric polarizability of the neutron is the same as that of the proton within the experimental uncertainties. The result also indicates that the magnetic polarizability of the neutron is larger than that of the proton. (Less)
Please use this url to cite or link to this publication:
author
opponent
  • Prof Kolb, Norman, University of Saskatchewan, Canada
organization
publishing date
type
Thesis
publication status
published
subject
keywords
Compton scattering, photonuclear reactions, deuteron, differential cross sections, 50-70 MeV, polarizability, tagged photons, Nuclear physics, Kärnfysik, Fysicumarkivet A:2002:Lundin
pages
144 pages
publisher
Department of Physics, Lund University
defense location
Föreläsningssal B, Fysiska Institutionen
defense date
2002-05-29 10:15
external identifiers
  • Other:ISRN: LUNFD6/(NFFR-1018)/1-144/(2002)
ISBN
91-628-5244-2
language
English
LU publication?
yes
id
38d6d479-6f5b-4968-abe2-955cdd710dca (old id 20796)
date added to LUP
2007-05-28 08:56:25
date last changed
2016-09-19 08:45:14
@misc{38d6d479-6f5b-4968-abe2-955cdd710dca,
  abstract     = {A series of three Compton scattering experiments on deuterium have been performed at the high-resolution tagged-photon facility MAX-lab located in Lund, Sweden. The 50 &lt; Eg &lt; 70 MeV tagged photons were scattered from a liquid deuterium target and detected simultaneously in three (10"x10") NaI detectors. The average laboratory angles investigated were 45, 125 and 135 deg. The influence of the inelastic contribution was minimized by implementing a narrow elastic fit-region in the missing energy spectra. Absolute cross sections were extracted for average photon energies of 55 and 66 MeV at each angle and for each experiment. The extracted cross sections are in good agreement with those measured at Illinois by Lucas et al.<br/><br>
<br/><br>
The difference between the electric and magnetic isospin-averaged polarizabilities of the nucleon inside the deuteron, was varied within the calculations of Levchuk and L'vov to best reproduce the data, holding the sum fixed at 14.6 (10-4 fm3). The result implies that the electric polarizability of the neutron is the same as that of the proton within the experimental uncertainties. The result also indicates that the magnetic polarizability of the neutron is larger than that of the proton.},
  author       = {Lundin, Magnus},
  isbn         = {91-628-5244-2},
  keyword      = {Compton scattering,photonuclear reactions,deuteron,differential cross sections,50-70 MeV,polarizability,tagged photons,Nuclear physics,Kärnfysik,Fysicumarkivet A:2002:Lundin},
  language     = {eng},
  pages        = {144},
  publisher    = {ARRAY(0x7c39b60)},
  title        = {Compton Scattering from the Deuteron at Low Energies},
  year         = {2002},
}