SigmaCalc recent development and present status of the evaluated cross-sections for IBA

Track Date and time Hall Duration
Invited Lectures Monday, 15. June 2015., 10:30 Orhideja Hall 30’

Alexander F. Gurbich (1), (2)

  1. Institute for Physics and Power Engineering, Bondarenko sq. 1, Obninsk, 249032, Russia
  2. National Research Nuclear University MEPhI, Kashirskoe shosse 31, Moscow, 115409, Russia

The evaluation of the cross-sections for any particular reaction consists in the elaboration of the most accurate possible cross-sections through incorporation of the all relevant experimental data in the framework of nuclear physics theory. The SigmaCalc Web site was developed as an interface to the evaluated cross-sections in order to provide IBA practitioners with an access to the evaluated data. Initially it was hosted by Surrey University, UK and then by the IAEA while this was technically possible. After a devastating hacker attack in 2012 the SigmaCalc site was shut down along with other nuclear data services located at the IAEA server and after a long period of outage it was moved first back to Surrey University and then to the server of the Institute for Nuclear Power Engineering in Obninsk, Russia, where it is currently hosted (http://sigmacalc.iate.obninsk.ru).

In the new 2.0 version of SigmaCalc the results of the evaluations performed during the SigmaCalc outage as well as the evaluations recently made including the cross-sections for PIGE were added. Many corrections were made in the previously evaluated cross-sections following a feedback from the SigmaCalc users and the results of benchmarks, i.e. integral experiments which consisted of measurements of charged-particle spectra from well characterized uniform thick targets followed by standard simulations using microscopic cross-sections. The idea of benchmarking is to verify the validity of the data for the purpose they are intended for through their use in a typical application. A database of the available benchmarks was incorporated into SigmaCalc and a feature was developed to compare spectra simulated using the evaluated cross-sections against benchmarks.

In order to provide users with possibility to compare evaluated differential cross-sections with the available results of the cross-section measurements the presentation of the calculated cross-sections was modified to combine them with experimental data taken on the fly from IBANDL. In the case of the data for PIGE there is also possibility to compare the evaluated data both with experimental cross-sections and with thick target yields, the evaluated cross-sections being converted into the thick target yield on the fly. Though a majority of most wanted cross-sections have already been evaluated there are still numerous gaps. Also the extension of the evaluated cross-sections up on energy is vital in some cases. The work on the cross-section evaluation and SigmaCalc site development is in progress with the ultimate goal of making SigmaCalc a versatile tool which will meet all needs of the IBA community in the cross-section data.