New GSI Analysis System GO4  

Participants: R. Barth, H. Essel, A. Heinz, S. Hofmann, R. Holzmann, M. Kaspar, P. Koczon, C. Kozhuharov, N. Kurz, M. Richter, K. Schmidt, K.H. Schmidt

Distribution: H. Brand, P. Braun-Munzinger, S. Glückert, H. Göringer, N. Herrmann, H. J. Kluge, W. Koenig, U. Krause, U. Lynen, V. Metag, W.F.J. Müller, G. Münzenberg, V. Schaa, C. Scheidenberger, C. Schlegel, H. J. Specht, R. Steiner, E. Stiel, K. Sümmerer, H. Winter, R. Fox, K. Suzuki

• A status paper about LEA has been distributed by H. Essel (see also go4 www page).

The experiments at the Fragment Separator FRS could be divided into two set-ups with 100 – 300 parameters in total:

• measurements of cross sections of fragmentation and fission products with the acquisition of FRS settings (creation of isotopes). Parameters involved:
  • beam counters
  • up to 6 tracking detectors
  • time-of-flight and position counters (2 scintillators)
  • 2 MUSIC chambers (8 * energy loss + 8 horizontal positions)

• measurements of the fission of secondary projectiles (fragmentation)
  • up to 6 tracking detectors
  • time-of-flight and position counters (2 scintillators)
  • 2 MUSIC chambers (8 * energy loss + 8 horizontal positions)
  • active target (3 * energy loss)
  • TWIN MUSIC chamber (16 * energy loss + 8 horizontal positions)
  • time-of-flight wall (32 time signals, 32 charge signals)

The analysis must identify the isotopes of the secondary projectiles in the FRS and the Z and total kinetic energy TKE of the fission fragments behind the FRS. Similar kind of data analysis has to be performed for a great number (100 to 1,000) of different FRS settings. Therefore, a high degree of automation in the analysis is required.

The software currently used is the extended SATAN program system ported from MVS to OpenVMS in 1994/1995. SATAN has several good features:

• a monolithic system where users have to write their own analysis program only. All the rest is handled by commands or command procedures (EXEC files). This makes the use very simple and clear.
• the input of list mode data allows
  • ASCII format
  • GOOSY format with filters on different types (sub-events)
  • EDAS (SATAN) format
• 1-dim (continuos or discrete values) and 2-dim (equidistant) data arrays (spectra or analyzers) can be read in ASCII format
• graphic output goes to Xwindow or PostScript
• libraries of spectra can be created in a compressed ASCII format. These data can be input to the corresponding SATAN-GD graphics package.
• all numeric results of commands can be stored into interactive parameters or in datasets.
• there are specific commands for:
  • graphics
  • a powerful fit package
  • automatic peak finding in 1-dim spectra
  • automatic setting of polygon windows in 2-dim spectra (banana windows)
  • automatic or semiautomatic finding of ridges stored then in 1-dim spectra
• the command language (EXEC) allows non-interactive and recursive executions of command lists including DO-loops, SELECT-loops, IF etc.

The philosophy of SATAN could be given in three main features:

• simple access and easy learning
  • only the necessary amount of complexity
  • user programming only in one place (analysis program) (in fact also in command lists)
  • analysis functions provided by macros
  • all other functions provided by commands
• dynamic organization of memory
  • only the used amount of memory is allocated
  • free dynamic creation and destruction of spectra (analyzers)
• easy and reliable archiving of spectra and graphic data
  • spectra are dumped in the same way graphic data is dumped
  • graphic dumps contain all details of a representation including data, scales, comments, errors, windows, etc., i.e. a data representation can be redone and even modified easily at any time.

In the discussion it was made clear that a well tailored system is always easier to learn and handle than a more flexible one. Nevertheless go4 should take into account that its acceptance will depend on a compromise between an easy user interface and a full functional system.

The information about how data were analyzed and how data are produced will normally be lost after a PhD student left the institute. Therefore all possible information should be stored in the data themselves. The use of data bases might be necessary to get a better archive and logging standard, although one would not like to depend on commercial products.

The project members agreed in first regular meetings twice a week on

The next meetings and their agenda:

M. Richter, August 17, 1998

Downloads-Manuals-References

GSI Helmholtzzentrum für Schwerionenforschung, GSI
Planckstr. 1, 64291 Darmstadt, Germany 
For all questions and ideas contact: J.Adamczewski@gsi.de or S.Linev@gsi.de
Last update: 27-11-13.