Updated Users' Guide for RSAP -- A Code for Display and Manipulation of Neutron Cross Section Data and SAMMY Fit Results

RSAP [1] is a computer code for display and manipulation of neutron cross section data and selected SAMMY output. SAMMY [2] is a multilevel R-matrix code for fitting neutron time-of-flight cross-section data using Bayes' method. This users' guide provides documentation for the recently updated RSAP code (version 6). The code has been ported to the Linux platform, and several new features have been added, including the capability to read cross section data from ASCII pointwise ENDF files as well as double-precision PLT output from SAMMY. A number of bugs have been found and corrected, and the input formats have been improved. Input items are parsed so that items may be separated by spaces or commas

Semi-empirical formulas for heavy-ion stripping data

All available charge state measurements for heavy ions in dilute gases and carbon foils at equilibrium or near-equilibrium conditions have been analyzed to improve semi-empirical formulas for the distribution parameters. Each experimental distribution was fit to an asymmetric function F q = Fm : exp {— 0.5 t2/(1 + εt) }, where t = (q — q0)/ρ and q0 is the maximum intensity charge value. Subsequent fits of the resultant distribution parameters q0, p, and ε to empirical functions of projectile charge and velocity yielded rms deviations of about 0.5 for q 0, 4 % for q0/Z, 5-7 % for p, and 0.03 for ε/ρ. The asymmetric distribution gives substantial improvement over previous expressions for prediction of small Fq values for heavy ions in dilute gases.Toutes les mesures d'état de charge disponibles pour les ions lourds dans les gaz dilués et les feuilles de carbone à l'équilibre ou dans des conditions proches de l'équilibre ont été analysées afin d'améliorer les formules semi-empiriques pour les paramètres de distribution. Chaque distribution expérimentale doit s'accorder à une fonction asymétrique Fq = F m exp (— 0,5 t2/1 + ε t), ou t = (q — q0)/ρ et q0 est l'état de charge la plus intense. On constate que l'ajustement des paramètres de la distribution (q0, p et ε) en fonctions empiriques de l'état de charge et de la vitesse conduit à des déviations standard de 0,5 pour q0, 4 % pour q0/Z, 5 à 7 % pour q et 0,03 pour ε/p. Les distributions asymétriques donnent une amélioration substantielle par rapport aux expressions antérieures pour la prédiction des faibles valeurs de fq pour les ions lourds dans les gaz dilués

R-Matrix Evaluation of Cl Neutron Cross Sections up to 1.2 MeV

We have performed an evaluation of {sup 35}Cl, {sup 37}Cl, and {sup nat}Cl neutron cross sections in the resolved resonance region with the multilevel Reich-Moore R-matrix formalism. Resonance analyses were carried out with the computer code SAMMY, which utilizes Bayes' method, a generalized least squares technique. A recent modification of SAMMY enabled us to calculate charged particle penetrabilities for the proton exit channel. Our resonance parameter representation describes the data much better than does ENDF/B-VI, and it should lead to improved criticality safety calculations for systems where Cl is present

Poloidal VV currents, disruption-induced VV forces, and TSC-EIGENCIRC interfaces

This paper discusses the following topics: Poloidal vacuum vessel currents induced by toroidal flux changes; TSC disruption-induced forces on the CIT 2.10m vacuum vessel; status of EIGENCIRC-TSC interface; and TSC disruption run with external TF structure. 6 figs., 2 tabs. (LSP

Calculation of radial and vertical forces on the CIT 1. 75 m vacuum vessel for several TSC disruption scenarios

The report consists of viewgraphs. (WRF

RSAP - A Code for Display of Neutron Cross Section Data and SAMMY Fit Results

RSAP is a computer code for display of neutron cross section data and selected SAMMY output. SAMMY is a multilevel R-matrix code for fitting neutron time-of-flight cross-section data using Bayes' method. RSAP, which runs on the Digital Unix Alpha platform, reads ORELA Data Files (ODF) created by SAMMY and uses graphics routines from the PLPLOT package. In addition, RSAP can read data and/or computed values from ASCII files with a format specified by the user. Plot output may be displayed in an X window, sent to a postscript file (rsap.ps), or sent to a color postscript file (rsap.psc). Thirteen plot types are supported, allowing the user to display cross section data, transmission data, errors, theory, Bayes fits, and residuals in various combinations. In this document the designations theory and Bayes refer to the initial and final theoretical cross sections, respectively, as evaluated by SAMMY. Special plot types include Bayes/Data, Theory--Data, and Bayes--Data. Output from two SAMMY runs may be compared by plotting the ratios Theory2/Theory1 and Bayes2/Bayes1 or by plotting the differences (Theory2-Theory1) and (Bayes2-Bayes1)

R-Matrix Evaluation of 160 Neutron Cross Sections up to 6.3 MeV

We have evaluated {sup 16}O neutron cross sections in the resolved resonance region with the multilevel Reich-Moore code SAMMY. Resonance parameters were determined by a consistent analysis, including both Doppler and resolution broadening effects. To properly treat the {alpha} particle exit channel, an algorithm to calculate charged particle penetrabilities and shifts was incorporated into SAMMY

Structural analysis of the ITER vacuum vessel from disruption loading with halo asymmetry

Static structural analyses of the ITER vacuum vessel were performed with toroidally asymmetric disruption loads. Asymmetric halo current conditions were assumed to modify symmetric disruption loads which resulted in net lateral loading on the vacuum vessel torus. Structural analyses with the asymmetric loading indicated significantly higher vessel stress and blanket support forces than with symmetric disruption loads. A recent change in the vessel support design which provided toroidal constraints at each mid port was found to be effective in reducing torus lateral movement and vessel stress

Electromagnetic loads on ITER in-vessel components

Design of the vacuum vessel and internal blanket/shield modules for the International Thermonuclear Experimental Reactor (ITER) is strongly influenced by the magnitude of electromagnetic loads due to plasma disruption. Calculations with the finite element code, EddyCuFF, have been performed to quantify these loads and incorporate them into the design process. A multifilament model of plasma motion and current decay has been developed using data generated by the Tokamak Simulation Code (TSC). Comparison with calculations employing single filament plasma models illustrates the need to use self-consistent, distributed plasma scenarios when analyzing toroidally segmented components. Application is made to design and analysis of the high aspect ratio design (HARD) option vessel and blanket/shield modules. Variations in geometry, response characteristics, and electromagnetic loads are compared to the reference design values. 5 refs., 8 figs., 4 tabs

Current status of the R-Matrix code SAMMY, with emphasis on the relationship to ENDF formats

During the last decade, advances in evaluations of neutron-induced cross sections in the resolved resonance region have surpassed the ability of the Evaluated Nuclear Data Files (ENDF) to make use of those evaluations. At the higher energies used in new evaluations, effects that in the past were deemed to be negligible are now important. There is also a great demand for including uncertainty information in ENDF files. In this paper, we describe recently approved ENDF formats to accommodate new evaluations and their implementation in SAMMY. Other new features of the SAMMY code, available in the 2006 Revision 7 release, are also described