Difference between revisions of "Tagger trigger timing"

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Below is tagger trigger timing information I got from Eugene Pasyuk.  Note that cables are trimmed so the sum of all delays is the same for all T-counters<br><br>
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Below is tagger trigger timing information I got from Eugene Pasyuk.  Note that cables are trimmed so the sum of all delays is the same for all T-counters.  This is calculated using existing cables.<br><br>
  
 
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       <td valign="top">80 ns?<br></td>
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       <td valign="top">150 ns<br></td>
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       <td valign="top">cable to BCAL Trigger Supervisor (not installed yet)<br></td>
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       <td valign="top">cable to BCAL Trigger Supervisor<br></td>
 
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       <td valign="top">5 ns<br></td>
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       <td valign="top">50 ns<br></td>
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       <td valign="top">cable to ADC crate<br></td>
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       <td valign="top">ADC gate generation, cables to ADC crate, ADC internal<br></td>
 
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       <td valign="top">'''280 + 80 ns?'''<br></td>
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       <td valign="top">'''325 + 150 ns'''<br></td>
 
       <td valign="top">'''total delay'''<br></td>
 
       <td valign="top">'''total delay'''<br></td>
 
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Note that the photon flight time from the radiator to the BCAL detector is about 100 ns, and that the RadPhi setup has 250 ns delay cables (straight, or 80+170 using a patch panel).
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Note that the photon flight time from the radiator to the BCAL detector is 115 ns, and that the RadPhi setup has 300 ns delay cables (straight, or 100+200 using a patch panel).
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Thus using existing cables the trigger delay is 325+150=475 ns minus the flight time 115 ns gives 360 ns, longer than the 300 ns ADC delay cables. 
  
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Also note that the RadPhi delay cables are 250 ns.  If the trigger delay is 360 ns then we will need additional delay unless the photon flight time is more than 110 ns.  The flight time is around 100 ns so we are right on the edge.  There are additional 170 ns delay cables in the RadPhi setup we can use if necessary (see Richard's note on RadPhi cables).
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See [[Overall tagger timing]] for further discussion.

Latest revision as of 14:16, 21 July 2006

Below is tagger trigger timing information I got from Eugene Pasyuk. Note that cables are trimmed so the sum of all delays is the same for all T-counters. This is calculated using existing cables.

Delay
 Location
25 ns
 electron flight time tagger radiator to farthest T-counter
20 ns
 internal T-counter PMT
50 ns
 cable to CFD
15 ns
 internal CFD
5 ns
 cable to L-R coincidence logic module
5 ns
 internal L-R coincidence logic module
10 ns
 cable to Master Or module
20 ns
 internal MOR
80 ns
 cable to forward carriage
150 ns
 cable to BCAL Trigger Supervisor
45 ns
internal Trigger Supervisor
50 ns
 ADC gate generation, cables to ADC crate, ADC internal
325 + 150 ns
 total delay


Note that the photon flight time from the radiator to the BCAL detector is 115 ns, and that the RadPhi setup has 300 ns delay cables (straight, or 100+200 using a patch panel).

Thus using existing cables the trigger delay is 325+150=475 ns minus the flight time 115 ns gives 360 ns, longer than the 300 ns ADC delay cables.

See Overall tagger timing for further discussion.

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