Beamline Setting Information

General Description

There are several magnets that steer and focus the beam into the target of the PiBeta detector. The current in those magnets can be controlled either manually or electronically using the program Setpoint (currently run on PC1529). The application is sufficient for all needs once the beam is set up. Here are the 3 files that one needs for Setpoint and for Optima: pibeta05.set, optima.cmd or pibeta.cmd, and device.lis on PC130. These settings were used in 2000, 1999 summer run and were not much different from 1998 run. The table below shows what the ADC readout values should be when the settings from the file above are put into Setpoint. For ASZ51 one can see a scaling factor of 0.3. This is due to the current limit of 150 A for this magnet. The setpoint DAC value gives the ratio relative to these 150 A, but the read back ADC value gives the portion relative to the full scale of 500 A. Setpoint shows the readback values always with an * and beeps all few seconds.

You may find some more information in this file by Jason Koglin

Click here to learn about the controls of the magnets

Click here to learn about the operation of the slits

Click here to learn how to use Optima

Magnets' and Beamline settings in Setpoint
First screen (magnets)  Second screen (slits) 
Name DAC Setting * ADC reading Function/Description Name DAC Setting ADC reading Function/Description
QTH51 -1197 (-2255) -0.2894  FSH51 Varying Varying
QTH52 589 (1115) 0.1409  FSH52  Varying Varying 
ASZ51  2876 (5474)  0.2107  DSC51 0 0.0559
QTB51 -105 (-151) -0.0252  DSC52 369 0.3641
QTB52 123 (173) 0.0281  FS53-O 390 0.3900
ASY51 718 (1316) 0.1722 FS53-U 390 0.3902
QSL51 0 0.0017 FS53-L 420 0.4200 
QSL52 0 0.0000 FS53-R  420 0.4205
ASL51 12191 (27637)  0.1829 
QSL53 476 (734)  0.1158
QSL54 -650 (-1212) -0.1560
SSL51  -450 (-702)  0.1094
QSK51 943 (1657) 0.2259 
QSL55 -964 (-1704) -0.2322
QSK52 1029 (2005)  0.2471
* The values given in parentheses are the same values in octal system. They should be used if the values on the magnets have to be set manually.  ** Magnets having names Q**XX are quadrupoles, those named A**XX are dipoles, and SSL51 is a steering magnet.

Jason Koglin has created a Beamline Settings Excel Worksheet to calculate DAC settings from the magnetic fields and magnetic fields from DAC settings.  This also contains all the magnet parameters and formulas necessary to make these calculations and has enough notes that it should one should need no further explanation.

A. Lebedev, July 29, 1999