version 2.0

I. DIRC magnetic probes

There are 4 ferro-probes, mounted on the SOB at 12 o'clock (probe#1), 4 o'clock (probe#2), 6 o'clock (probe#3) and at 8 o'clock (probe#4), viewing the SOB from the north towards the south.

The 4 cables from these probes are temporarily routed ACROSS the face of the SOB doors, terminating in a CAMAC crate in Rack#5 on the cryogenic platform above the detector. This means that they must be disconnected when the SOB is opened. This will be changed in the future when longer cables are available.

The modules have a test signal switch which is normally OFF, while the crate is normally ON (of course!).

A long cable connects the CAMAC crate to a VSAM module in Rack#7 in the electronics hut. The crate with the VSAM has the module MVME 177-013. The crate is normally ON (!).

Though our experience is limited at the moment, typical values for the modulus of B are:

           Is=0       Is=4600     Is=4600  Is=4600         Is=0
           Ib=0       Ib=200      Ib=0     Ib=200          Ib=200
        (depends on   (no demag            (after demag    (after solen
          history)       cycle)                  cycle)          crash)

 probe#1    0.5        1.5         3.0      2.5 (?)         3.8
 probe#2    0.4        0.9         4.7      0.5             5.0
 probe#3    0.3        0.5         4.0      0.4             5.0
 probe#4    0.2        0.7         4.2      0.6             5.7

The values of the ferro-probes are displayed by the Slow Control, for example from a SLAC terminal:

         ssh bbr-dev02
         source ~wormser/dcl
         and click on B-Field 
         The 4 ferro-probe values are in middle of the display.