Graduate Thesis Or Dissertation
 

Determining cross sections for potential medical radioisotopes

Public Deposited

Contenu téléchargeable

Télécharger le fichier PDF
https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/xp68kk40f

Descriptions

Attribute NameValues
Creator
Abstract
  • Cost effective medical isotope production is key to the success of many forms of radiation therapy. A lymphoma clinical trial for copper-67 was canceled in 1997 due to insufficient production quantities of the isotope (Fast Flux Test Facility, 2001). To date high flux thermal reactors and particle accelerator facilities have received the bulk of the production load; however, low flux thermal reactors can and should carry some of this load, perhaps even more economically in some cases. It is the primary goal of this research to demonstrate the viability of low flux thermal reactor medical isotope production. A secondary premise of this research is to suggest that isotopes with the same desirable nuclear properties as those in widespread use have not been fully considered due to a lack of information. Simply put, medically important cross sections are either not known or are not known with a reasonable degree of certainty. Four potential medical radionuclides were identified as lacking sufficient cross section data. These cross sections were measured to confirm or update older data and remove some of the "uncertainty." The four isotopes identified as having desirable nuclear and chemical characteristics to serve as medical isotopes are: scandium-47 (⁴⁷Sc), copper-67 (⁶⁷Cu), yttrium-91 (⁹¹Y), and the metastable state of tin-117 (¹¹⁷ᵐSn). Irradiation methods were designed to isolate both epithermal and thermal reaction cross section data, as well as unfold the fast flux (fission spectrum) since three of the reactions are neutronproton threshold reactions. Samples were irradiated and counted, and the reaction cross section values were calculated from the measured activity. Values were then compared to accepted values to determine if further study is warranted. Production of medical isotopes in a thermal reactor can be a viable alternative and merits further comparative study. Three of the four reactions studied produced appreciable amounts of potential medical isotopes over a short irradiation period of three megawatt-hours, the exception being ⁹¹Y. With little knowledge of the actual OSTR flux profile, a methodology was proven to "pin" the profile and accurately measure cross sections. The fission average cross section for the ⁶⁷Zn(n,p) reaction of 1.07 ± 0.113 mb (one sigma) was found to be exactly the same as the widely adopted value. ⁴⁷Ti(n,p) yielded a 15.5 ± 1.6mb (one sigma) fission average cross section, which is slightly less than the ENDF/IB-VI value of 22.4 mb. These results support the conclusion that medical isotope production in thermal reactors is feasible and continued research is warranted.
Resource Type
Date Available
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Academic Affiliation
Non-Academic Affiliation
Subject
Déclaration de droits
Publisher
Peer Reviewed
Language
Digitization Specifications
  • File scanned at 300 ppi (Monochrome) using Capture Perfect 3.0.82 on a Canon DR-9080C in PDF format. CVista PdfCompressor 4.0 was used for pdf compression and textual OCR.
Replaces

Des relations

Parents:

This work has no parents.

Dans Collection:

Articles

La vignette Titre Date de téléchargement Visibilité actes
file details ColemanJosephW2004.pdf 2017-08-15 Public Télécharger