gecal2 - Tcl/Tk script help

please note: this file was generate by make_tcl from the file: gecal2.hlp. Please update that file and regenerate the gecal2.html. Do not update the gecal2.html file directly!


This Tcl/Tk script is meant for the energy calibration of the GAMMASPHERE germanium detector array.It serves a a help script for the gecal1 script which has the main calibration routines. The germanium and EFF list are maintained as in the gecal1 script - please see documentation there.


'Bical' is an 'old fashioned' two line calibration function. The two-line calibration routine is designed to give the first level energy calibration of the enabled detectors using, e.g., using a simple two line source like 207Bi. However, the procedure can equally well be used on two lines in a multi-line source like 152Eu (the 344Kev and 1408kev lines works well). The two line calibrator (Bical) must be supplied with i) two desired peak positions (in channels) and ii) associated search ranges (a low and a high channel) for these peaks. One can input these values by hand in the 'sunken' windows just above the 'two line cal' button. By specifying the desired peak positions one can control the gain and offsets of the germanium detectors. For convenience, there are three buttons (to the right of the red 'two line cal (Bi cal)' button) that allows for a quick-load of values for the 207Bi, 152Eu and 60Co sources with the standard gain of 0.5 Kev/ch and zero offset. All other sources or gains/offsets must currently be typed in by hand. The routine will locate the highest peak in the two search regions and use the mean of those peak positions (with a background subtraction) for the linear energy calibration. It does this by calculating what gain and offset to use in order to put the two peaks at the "desired peak position". The routine will take into account the current calibration coefficients, so there is no need to set the offset and gains to any particular values before executing the "two line cal" procedure.


The germanium spectra in the EFFs can be dumped ring by ring using the 'dump EFF spectra from each ring' button in this gecal2 Tcl/Tk script. The spectra are written in Radford format as: r17, r32, ... , r163. The routine will write a gf2 command file: 'rdisp.cmd' for easy display in Radfords gf2. This utility is great for finding the peak to Doppler correct - or check that the current Doppler correction is still good. The individual ring spectra can be used to find the mean value of a moving peak.


For each of the rings where you have found the mean position of a moving peak, input this mean position in the appropriate sunken window. Specify '0.0' for the rings where you did not determine a mean moving peak position. By pushing the 'find v/c' button, the routine will find the best v/c value to use to the moving peak will line up on the online spectra. The routine will do a relativistic calculation. Be careful to take into account any offsets in the spectra that was used to find the positions of the peaks. (compression of a spectrum will introduce an offset!)


This utility allows you to "manually" correct the gain and offset of a particular detector. You need to specify the channels of two reference peaks and their energies and the program will determine the new values of the gain and offset. You have the option of a dry run to inspect the results before the actual adjustment. NOTE: If you use GF2 spectra you should multiply the channels by 2. If you are using DAMM spectra you should multiply by 4


This utility allows you to dump a buffer from the sender. The header of the buffer is interpreted but the data itself is dumped as is. However, for readability, the event seperators are marked. You must make sure the sender is on and sending the data to the machine you start this dump utility from


There are several utilities that pertain to the alignment of the germanium times. The germanium time spectra in the EFFs can be cleared ("clear") and the time spectra can be recovered and stored in Radford spectra files for display in gf2 ("dmp"). The is also a function to set the offsets of the specified germaniums to a particular value ("set offset"). By pushing the "align ge times" button, an offset is calculated for each detector so that the times of the selected germanius are ligned up. When the spectra are dumped command files for display are generated. The x1.cmd displays all spectra overlayed and x1.cmd displays the spectra one at a time. The ref.cmd file will display the current spectra overlayed with the reference spectra dumped at the beginning of the run overlayed. There are also tools for storage of the current time aligment offsets in a file ("store", blue button) and restore those values again ("restore", red button)


When the individual reference spectra are not perfectly aligned, is is useful to be able to sum them up and use the sum as the reference spectrum for the individual germanium detectors. This utility allows this to be done. Only the selected germanium reference spectra are summed and the sum will overwrite the current reference spectra. A backup version of the old (individual) reference spectrum is written out before the replacement.