From: W.J. Llope (llope_at_physics.rice.edu)
Date: Fri Feb 21 2003 - 10:50:25 EST
was that TOFp ADC replaced last wednesday?
At 8:26 PM -0600 2/19/03, Frank Geurts wrote:
>Xu, Zhangbu wrote:
>[ ...]
>>
>>Frank and I will check two things:
>>1) measure the timing delay between first discriminator and the
>>output from West and East coincidence.
>
>During today's access, Zhangbu measured the timing between the input
>to the 3rd discrimination of pVPD W3 (PS708, 1-11-6) and the output
>of the WEST coincidence (LC365, 2-12-2) to be 27ns. For more details
>see http://mac8.rice.edu/~TOF/TOFp/operations/manuals/local_trg.html
>and the reference to the Run-III diagram.
>
>2) Measure the effect of the second output from Model 706 discriminator.
>
>The second test we did was measuring the contribution to the time
>resolution from loading one or two channels of a PS706
>discriminator. The setup (see diagrams in above link) involved
>temporarily replacing the quad input, which is used as a fan-out
>unit (LC622, 2-9-1) with a spare ps706 channel. In this test we
>either one or two of the PS706 outputs and ran the local DAQ in a
>pulsing stand-alone mode.
>
>A quick analysis shows that on the average the time-resolution of
>all 72 TOFr channels, as expected, detoriates but only with some
>0.02 to 0.03 TDC bins which translates into roughly 1 to 1.5ps.
>
>
>3) Zhangbu removed the 4ns cable and the fan-out unit which sends
>the EAST and WEST coicidences to his trigger rack. This should safe
>at least some 12ns in the "STAR pVPD-trigger" timing. With the
>additional removal of a discriminator on his side the STAR-pVPD
>trigger ought to be timed in properly now.
>
>-frank
--W.J. Llope, Ph.D. Res. Assoc. Professor T.W. Bonner Nuclear Laboratory phone: 713-348-4741 Rice University, MS-315 fax: 713-348-5215 6100 S. Main St. Houston, TX 77005-1892 e-mail: llope_at_physics.rice.edu WWW home: http://wjllope.rice.edu/default.html
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