NEA-1665 UMG 3.3

1. NAME OR DESIGNATION OF PROGRAM:  UMG 3.3.

3. DESCRIPTION OF PROGRAM OR FUNCTION

UMG (Unfolding with MAXED and GRAVEL) is a package of seven programs written for the analysis of data measured with spectrometers that require the use of unfolding techniques.
  
The program MAXED applies the maximum entropy principle to the unfolding problem, and the program GRAVEL uses a modified SAND-II algorithm to do the unfolding. There are two versions of each: MXD_FC33 and GRV_FC33 for "few-channel" unfolding (e.g., Bonner sphere spectrometers) and MXD_MC33 and GRV_MC33 for "multi-channel" unfolding (e.g., NE-213).
  
The program IQU can be used to calculate integral quantities for both MAXED and GRAVEL solution spectra and, in the case of MAXED solutions, it can also be used to calculate the uncertainty in these values as well as the uncertainty in the solution spectrum. The uncertainty calculation is handled in the following way: given a solution spectrum generated by MAXED, the program IQU considers variations in the measured data and in the default spectrum and uses standard methods to do sensitivity analysis and uncertainty propagation. There are two versions: IQU_FC33 for "few-channel" unfolding and IQU_MC33 for "multi-channel" unfolding.
  
The program UMGPlot can be used to display the results from the unfolding programs MAXED and GRAVEL in graphical form in a quick and easy way.

4. METHODS

MAXED is based on the maximum entropy principle. The solution to the unfolding problem is obtained by maximisation of the relative entropy (used here in the form due to Skilling, which is a generalisation of the usual expression to distributions that are not necessarily normalized) subject to constraints imposed by the measurements. This approach permits the inclusion of prior information in a well-defined and mathematically consistent way, and it leads to a solution spectrum that is a non-negative function which can be written in closed form. This last feature permits the use of standard methods for sensitivity analysis and propagation of uncertainties, which are implemented in the program IQU.
  
GRAVEL is an iterative unfolding program that was first developed for the HEPRO package. It uses a slight modification of the SAND-II algorithm.

5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM

The "few-channel" programs MXD_FC33, GRV_FC33 and IQU_FC33 can analyse data sets with up to 100 measurements and can handle fluence vectors with up to 1000 energy bins.
  
The "multi-channel" programs MXD_MC33, GRV_MC33 and lQU_MC33 can analyse data sets with up to 4096 measurements and can handle fluence vectors with up to 4096 energy bins.

6. TYPICAL RUNNING TIME

The running time will depend on the complexity of the problem, the number of measurements and the number of energy bins used to describe the fluence vector.
On a PC with an Intel Pentium Ill, 866 MHz, 256MB, the running times for the examples included in the package are of the order of:
MXD_FC33: < 10 s
GRV_FC33: < 2s
IQU_FC33: <2s
MXD_MC33: 210 s
GRV_MC33: 450 s
IQU_MC33: 100 s
Large, complex problems may require more time: for example, MXD_MC33 may require one hour or more when the number of measurements and the number of energy bins used to describe the fluence vector are close to the maximum allowed values.

The time to compute the sample problems of version NEA 1665/03 tested at the NEA Data Bank varies from 5 min. 3s. to 24 min. 31s.

8. RELATED OR AUXILIARY PROGRAMS

The UMGPlot graphical interface is available for DOS/Windows only.

10. REFERENCES

M. Reginatto and P. Goldhagen, "MAXED, A Computer Code For Maximum Entropy Deconvolution Of Multisphere Neutron Spectrometer Data", Health Phys. 77, 579 (1999).
  
M. Reginatto, P. Goldhagen. and S. Neumann, "Spectrum unfolding, sensitivity analysis and propagation of uncertainties with the maximum entropy deconvolution code MAXED", Nucl. Instr and Meth. A 476,242 (2002).
  
J. Skilling, "Classic maximum entropy", in: Maximum entropy and Bayesian methods, ed. J. Skilling (Kluwer Academic Publishers, Dordrecht, 1989).
  
M. Matzke, "Unfolding of Pulse Height Spectra: The HEPRO Program System", Report PTB-N-19, October 1994.

- Marcel Reginatto:
The "multi-channel" unfolding programs in the UMG package:
MXD_MC33, GRV_MC33 and IQU_MC33
(UMG package, version 3.3 - release date: March 1, 2004)
- Marcel Reginatto:
The "few-channel" unfolding programs in the UMG package:
MXD_FC33, GRV_FC33 and IQU_FC33
(UMG package, version 3.3 - release date: March 1, 2004)
- Manual for the Program UMGPlot

11. HARDWARE REQUIREMENTS

The complete package needs about 35 MBytes on the computer hard disk.

Version NEA 1665/03 has been tested at the NEA Data Bank on:
NEC Powermate CT Intel Pentium III 800MHz
HP 9000/800 rp5405 Bi-Processor 650MHz
DEC Alpha AXP 500MHz
IBM T40 Intel Centrino 1300MHz

13. SOFTWARE REQUIREMENTS

Any operating system. Executables are provided for computers running Windows 95+ with a DOS box or computers running plain DOS 6.22+.
  
The package comes with installation programs that can be used for Windows 95/98/ME and Windows NT/2000/XP (in the case of other platforms, the package must be installed manually).

Version NEA 1665/03 has been tested at the NEA Data Bank on the following operating systems:
MS WINDOWS 2000 Professional (US Version)
HP-UX B.11.11
DEC OSF-1 V4.0 1229
MS Windows XP Professional (German Version)
Suse Linux 8.1 Kernel 2.4.
    
and with the following compilers:
Compac Visual Fortran 6.6 (Windows)
HP Fortran 90 V2.7.1
DEC Fortran 90 V5.2-705
Absoft Fortran 95 for Intel/Linux

14. OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS

The programs MAXED, GRAVEL and IQU were written in Fortran 90 and compiled with the Compaq Visual Fortran (version 6.1) compiler.
  
The program UMGPlot was written using the programming environment ComponentOne Studio(TM) for ActiveX.
  
The installation programs were created using the "WinZip Self-Extractor 2.2" which initiates a batch file with DOS commands.

15. NAME AND ESTABLISHMENT OF AUTHORS

Marcel Reginatto, Burkhard Wiegel, Andreas Zimbal, Frank Langner (UMGPlot)
Physikalisch-Technische Bundesanstalt (PTB)
Department 6.5, "Neutron Radiation"
Bundesallee 100
38116 Braunschweig
GERMANY

FcMcWorkspace\  Compac Visual Fortran workspace structure
Manuals\  Documentation and graphs
Output\   Sample Output files
Win_9xME\ Instructions and installation for Win9x and Win ME
Win_NTXP\  Instructions and installation for WinNT and Win XP
Y_general directory