Log entry time 08:03:11 on March15,2009

Entry number 266254

Owl shift summary: Robert Michaels (SL), Miha Mihovilovic (3rd)

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EVENTS

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00:00 The start of the shift. Taking production data.





      

08:00 No beam all night. Hall A is still in contolled access. 



00:50 The Bigbite deadtime monitor starts showing negative deadtime

      (-70%) during the run #2164. The online analysis also showed

      huge negative deadtime. There are also peaks missing in the

      BB Cherenkov TDC data etc.  



01:30 Tried to power cycle TS12



01:45 Started new runs (#2166 and #2167). Deadtime is still negative,

	  and peaks in BB Cherenkov TDC data are still missing. 

	

02:05 Requested for Controlled access.



02:10 Bob Mihaels, Alexandre Camsonne and Brad Sawatzky went

	  down the Hall to fix the problem with BB electronics.	





02:40 Problems "fixed" (see halog).  Came out of hall.



03:00 Restart production



03:55 Negative dead time reappeares



06:25 BigBite wire chamber trip. L14.7 tripped  (Chamber 2). 



07:23 BigBite wire chamber trip. L14.7 tripped again (Chamber 2). 



RUNS

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Bigbite:



23:22-00:14 #2162  Production run, 3He, I = 15 uA, No. events = 6.5M

00:16-00:50 #2163  Production run, 3He, I = 15 uA, No. events = 6.5M

00:51-01:14 #2164  Production run, 3He, I = 15 uA, No. events = 5.7M

            (Negative deadtime)



Runs #2165 - #2173 are test runs ("junk") when we tried to resolve the 

			negative dead time problem. 

			            

02:55-02:57 #2174  Spot++ check,   3He, I = 2  uA, No. events = 11k

03:00-03:55 #2175  Production run, 3He, I = 15 uA, No. events = 6.4M	

			(Negative dead time reappeares - 69 %)

			

03:56-04:06 #2176  Test run for negative dead time No. events = 1.2M

04:07-04:56 #2177  Production run, 3He, I = 15 uA, No. events = 6.5M

04:58-05:33 #2178  Production run, 3He, I = 15 uA, No. events = 4.2M

05:34-06:24 #2179  Production run, 3He, I = 15 uA, No. events = 5.5M

			(Wire chamber trip)

06:29-07:23 #2180  Production run, 3He, I = 15 uA, No. events = 5.3M

			(Wire chamber trip)			





HRSL:



23:22-00:15 #20689 Production run, 3He, I = 15 uA, No. events = 221k

00:16-00:50 #20690 Production run, 3He, I = 15 uA, No. events = 152k

00:51-01:40 #20691 Production run, 3He, I = 15 uA, No. events = 96k

01:40-01:58 #20692 Production run, 3He, I = 15 uA, No. events = 76k

02:55-02:57 #20693 Spot++ check,   3He, I = 2  uA, No. events = 4k

03:00-03:55 #20694 Production run, 3He, I = 15 uA, No. events = 224k

04:05-04:57 #20695 Production run, 3He, I = 15 uA, No. events = 223k

04:58-05:33 #20696 Production run, 3He, I = 15 uA, No. events = 145k

05:34-06:24 #20697 Production run, 3He, I = 15 uA, No. events = 198k

06:29-07:23 #20698 Production run, 3He, I = 15 uA, No. events = 227k