Can cross sections be accurately known for priori?

PDF Version Also Available for Download.

Description

Distinct maxima and minima in the neutron total cross section uncertainties were observed in our large scale covariance calculations using a spherical optical potential. In this contribution we investigate the physical origin of this oscillating structure. Specifically, we analyze the case of neutron reactions on {sup 56}Fe, for which total cross section uncertainties are characterized by the presence of five distinct minima at 0.1, 1.1, 5, 25, and 70 MeV. To investigate their origin, we calculated total cross sections by perturbing the real volume depth V{sub v} by its expected uncertainty {+-}{Delta}V{sub v}. Inspecting the effect of this perturbation on ... continued below

Creation Information

Pigni,M.T.; Dietrich, F.S.; Herman, M. & Oblozinsky, P. June 24, 2008.

Context

This article is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided by UNT Libraries Government Documents Department to Digital Library, a digital repository hosted by the UNT Libraries. More information about this article can be viewed below.

Who

People and organizations associated with either the creation of this article or its content.

Publisher

Provided By

UNT Libraries Government Documents Department

Serving as both a federal and a state depository library, the UNT Libraries Government Documents Department maintains millions of items in a variety of formats. The department is a member of the FDLP Content Partnerships Program and an Affiliated Archive of the National Archives.

Contact Us

What

Descriptive information to help identify this article. Follow the links below to find similar items on the Digital Library.

Description

Distinct maxima and minima in the neutron total cross section uncertainties were observed in our large scale covariance calculations using a spherical optical potential. In this contribution we investigate the physical origin of this oscillating structure. Specifically, we analyze the case of neutron reactions on {sup 56}Fe, for which total cross section uncertainties are characterized by the presence of five distinct minima at 0.1, 1.1, 5, 25, and 70 MeV. To investigate their origin, we calculated total cross sections by perturbing the real volume depth V{sub v} by its expected uncertainty {+-}{Delta}V{sub v}. Inspecting the effect of this perturbation on the partial wave cross sections we found that the first minimum (at 0.1 MeV) is exclusively due to the contribution of the s-wave. On the other hand, the same analysis at 1.1 MeV showed that the minimum is the result of the interplay between s-, p-, and d-waves; namely the change in the s-wave happens to be counterbalanced by changes in the p- and d-waves. Similar considerations can be extended for the third minimum, although it can be also explained in terms of the Ramsauer effect as well as the other ones (at 25 and 70 MeV). We discuss the potential importance of these minima for practical applications as well as the implications of this work for the uncertainties in total and absorption cross sections.

Source

  • Covariance Workshop; Port Jefferson, New York; 20080624

Language

Item Type

Identifier

Unique identifying numbers for this article in the Digital Library or other systems.

  • Report No.: BNL--81627-2008-CP
  • Grant Number: DE-AC02-98CH10886
  • Office of Scientific & Technical Information Report Number: 939952
  • Archival Resource Key: ark:/67531/metadc898696

Collections

This article is part of the following collection of related materials.

Office of Scientific & Technical Information Technical Reports

Reports, articles and other documents harvested from the Office of Scientific and Technical Information.

Office of Scientific and Technical Information (OSTI) is the Department of Energy (DOE) office that collects, preserves, and disseminates DOE-sponsored research and development (R&D) results that are the outcomes of R&D projects or other funded activities at DOE labs and facilities nationwide and grantees at universities and other institutions.

What responsibilities do I have when using this article?

When

Dates and time periods associated with this article.

Creation Date

  • June 24, 2008

Added to The UNT Digital Library

  • Sept. 27, 2016, 1:39 a.m.

Description Last Updated

  • Nov. 1, 2016, 2:25 p.m.

Usage Statistics

When was this article last used?

Congratulations! It looks like you are the first person to view this item online.

Interact With This Article

Here are some suggestions for what to do next.

Start Reading

PDF Version Also Available for Download.

International Image Interoperability Framework

IIF Logo

We support the IIIF Presentation API

Pigni,M.T.; Dietrich, F.S.; Herman, M. & Oblozinsky, P. Can cross sections be accurately known for priori?, article, June 24, 2008; United States. (digital.library.unt.edu/ark:/67531/metadc898696/: accessed October 21, 2018), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT Libraries Government Documents Department.