S800 Spectrograph Inverse Map Server

This page is intended to provide a mean to obtain inverse maps for the S800 Spectrograph from the recorded settings of the magnets. This calculation involves many steps performed by various programs and takes on the average 20 seconds. The result is in the form of a standard COSY map in ASCII format which can be directly used by the standard S800 SpecTcl program.

The data needed as input for the calculation are the currents in the 4 magnets of the S800 Spectrograph, the magnetic rigidity and the mass and charge of the particle of interest. The distance between the target of the pivot point is normally zero for the nominal target location. Upstream locations correspond to positive values of this parameter. The focal plane shift can be used to fine tune the calculations based on comparison with kinematics. It accounts for variations of effective lengths in the dipoles and/or discrepancies between the CAD distances and reality. Downstream locations correspond to positive values of this parameter.

Q1 or I256QA current (Amps):                     
Q2 or I258QB current (Amps):                     
D1 or I265DS current (Amps):                     
D2 or I269DS current (Amps):                     
Brho or Magnetic Rigidity (Tesla.Meter):         
Mass number of particle of interest:             
Charge number of particle of interest:           
Distance between Target and Pivot Point (Meter):  (positive indicates upstream)
Focal Plane Shift (Meter):                        (positive indicates downstream)
NSCL experiment number:                          
Your Name:                                       
Email address:                                   

Please click the Submit button only once and wait a few seconds until the server returns the calculated map!

If you have entered a valid Email address the map will be sent to you automatically