FB Dead Tube Map

Here is a sample page from the Tube chamber dead tube map display, showing the x,d and y planes for side 2 quadrant 3. The x axis is labelled by tube channel number, but each bin has a width of 1/2 a tube. The y axis indicates the number of clusters found in each 1/2 tube. ( The cluster position is determined by the relative signal heights from a group of 5 ajacent tubes; for the purpose of plotting the dead tube map , the existing dead tube information is ignored when calculating the cluster positions.)

Identifying dead tubes

In the upper ( x, plane 1 ) plot, the band in channel 10 indicates that this tube is marked dead in the existing dead tube map. This is seen to be correct , because

• There are no clusters reconstructed within the tube
• The clusters in tubes 9 and 11 are displaced away from the dead tube ( below 9.5, above 11.5 in x )

The lack of hits in channels 18 and 28 indicate dead tubes, which have not been previously identified. These should be recorded as dead.To do this, the existing FBCP (tube plane constants bank ) is changed from

*DO FBCP 1 -iF -n32 

1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 0.0 1.0 1.0 1.0 1.0 1.0 1.0 

1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0

*--            +               |               +               

to

*-- S2Q3P1T18 DEAD, 23-06-98

*-- S2Q3P1T28 DEAD, 23-06-98

*DO FBCP 1 -iF -n32 

1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 0.0 1.0 1.0 1.0 1.0 1.0 1.0 

1.0 0.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 0.0 1.0 1.0 1.0 1.0

*--            +               |               +               

Note that

1. Comments have been added to indicate when the changes were made
2. The comment line following the bank groups the channels in blocks of 4, to help identify the correct one.

D plane plots

The d ( diagonal ) planes have 44 tubes in all, read out by 32 channels. The vertical dashed lines indicate which groups of tubes share the same channel number, and the x axis is labelled by channel ( not tube ) number, so no conversion is necessary