[Dsg-halla_ecal] Fw: ECal heater test

Mon Mar 10 12:00:02 EDT 2025

________________________________
From: Donald Jones <jonesdc at jlab.org>
Sent: Monday, March 10, 2025 11:50 AM
To: Mark Kevin Jones <jones at jlab.org>; Bogdan Wojtsekhowski <bogdanw at jlab.org>; Robert Myles <myles at jlab.org>; Jennifer Williams <jennifer at jlab.org>; Imani Burton <iburton at jlab.org>; Lawrence Hurt <lhurt at jlab.org>; Marc Mcmullen <mcmullen at jlab.org>; Chandan Ghosh <chandan at jlab.org>
Cc: Simona Malace <simona at jlab.org>; ralphmm at jlab.org <ralphmm at jlab.org>
Subject: Re: ECal heater test

Hi All,
Here is a revised heater test plan. Due to security and wildlife entry concerns, the guards will not allow the hall door to remain up overnight which requires slight modifications. We are also going to ensure that no level of VESDA alarm triggers. A VESDA zone first triggers a notification (not alarm) at 5 bars, so at any point during the test, if an observer sees a 3bar level, they will  activate the hall exhaust system manually. If this happens after hours, they will stand by the roll up door to continuously monitor the entry point ensuring no one/animal comes in. After 15-30 minutes of exhaust, the VESDA should once again show minimal levels. If levels do not return to low (1 bar or less), Robert Myles will be contacted and asked for advice. Note that the test on Friday ran as we expected from previous prototype tests except that it takes much longer to reach operating temperature. There were no alarming features that manifested themselves. We ran the prototype for several weeks with no incident and expect the same here. The purpose of this test is to demonstrate we can reach the temperature profile required and to do an initial burn off of  anything inside the detector (residual machining oil, fingerprints, etc) that are not temperature rated. Once we show that we can run at temperature without tripping the sensitive Hall smoke alarm (VESDA), this test is complete.

  1.
10PM Monday. Don J. will activate the heater system. We found on Friday that it took about 8-10 hours to get to the point where it began producing sufficient particulate to register on the VESDA. From midnight to 6AM Tues, Don will be onsite checking the VESDA system hourly to ensure it does not reach problematic levels.
  2.
6AM Tuesday. The detector is now expected to  be hot enough (>200degC) to create particulate levels seen by the VESDA. Robert Myles and his crew will be  onsite through out the day Tuesday to monitor VESDA levels and provide advice.
  3.
8AM Tuesday. The hall exhaust system is activated to reduce particulate so that work conditions are not impacted by the odors. It will remain on during the day.
  4.
10AM Tuesday. A second person (Hall staff member) takes over monitoring from Don for a 7 hr shift 10AM-5PM. They will check the VESDA levels and regulate temperatures as appropriate.
  5.
5 PM Tuesday. A third person (Hall staff member) takes over monitoring the system from 7PM to midnight. We do not see a need for continued monitoring from the fire crew during this time unless they deem it necessary. We will contact them if questions or raised levels of particulate arise.
  6.
6PM Tuesday. The hall exhaust system is deactivated and the roll-up door is closed for security reasons. From this point forward the monitor will check on VESDA levels hourly reacting as specified above if the particulate levels reach 3bars.
  7.
11:59PM Tuesday. By now we hope the crystals have reached target temperature. Don will once again take over for the night shift of monitoring, trying to reach equilibrium temperatures on the crystals that are within our experimental specifications (200-220 degC on the hot end). During the night VESDA levels will be checked hourly reacting as appropriate for increased levels. The guards should be notified that there may be periods of time during the evening and night when the exhaust system will be activated and the roll-up door opened. During those periods, the Hall A staff member monitoring the system will stand by the door to ensure no unsolicited entry occurs.
  8.
6AM Weds. Robert Myles and crew are once again onsite and the final phase of the test begins. The hall exhaust system is activated until VESDA levels are negligible. At this point, the exhaust is shut off and the roll-up door closed just like during an experiment. We  assume at this point that all burn off is complete and are trying to verify that the particulate level will remain low enough to run with all the doors closed. By noon or shortly thereafter on Weds, we expect to be able to verify that this is true and that we can run the experiment with the heater system/detector at operating temperatures.

-Don

Donald Jones
Hall A/C Staff Scientist
Jefferson Lab
Newport News, VA
________________________________
From: Donald Jones
Sent: Saturday, March 8, 2025 3:23 PM
To: Mark Kevin Jones <jones at jlab.org>; Bogdan Wojtsekhowski <bogdanw at jlab.org>; Robert Myles <myles at jlab.org>; Jennifer Williams <jennifer at jlab.org>; Imani Burton <iburton at jlab.org>; Lawrence Hurt <lhurt at jlab.org>; Marc Mcmullen <mcmullen at jlab.org>; Chandan Ghosh <chandan at jlab.org>
Cc: Simona Malace <simona at jlab.org>; ralphmm at jlab.org <ralphmm at jlab.org>
Subject: ECal heater test

Hi All,
As some of you know, we did a partial heater test for ECal last Friday. Due to the time it was taking we had to truncate it so that it didn't stretch well into the weekend. We now have some of the issues resolved, but I think realistically, it will take 36 to 48 hours to really complete the test and demonstrate performance. The purpose of the test is to 1. demonstrate we can reach the desired crystal temperature profile and retain an enclosure temperature well below 50 degC. And 2. show that we can run without setting off the VESDA alarms. The crystals take a long time to stabilize so I expect it will take closer to 48 hours to demonstrate this. Our test on Friday showed that the VESDA system does not start to react at all until heater temperatures are well above 200 degC, so here is the plan I propose.

  *
I will go in Sunday afternoon/evening and turn on the heater system, setting all zones to 140 degC. I will monitor it remotely to make sure everything is working as expected. The controls system operated very well on Friday so this should create no issues.
  *
Monday morning I will go in around 2AM and turn the system fully on to its final set point. By 6AM it will reach around 200 degC. I will check the VESDA levels regularly, but experience from Friday suggests they will not show anything. At this point 6AM and later, Robert Myles or one of his folks can begin monitoring the VESDA and by 8 AM we will likely start seeing slight levels of particulate.
  *
Lawrence will let folks know at the 8AM meeting to expect another day of heater testing in the hall.
  *
If the technicians and other folks want to keep working in the Hall, we can turn on the exhaust as needed for their comfort.  Robert can decide what level of monitoring is needed.
  *
Monday from 2-6PM Chandan will take over the monitoring and controls for me.
  *
We will leave the hall exhaust fan on and roll up door open overnight Monday evening/Tuesday morning so that Robert and his folks do not need to stay up overnight. We will keep an eye on the VESDA levels just in case.
  *
If Bogdan is willing, he will take over controls/monitoring from 6PM to midnight. At midnight, I will return and do the night shift.
  *
By Tuesday morning, we should have all temperatures stabilized and burn off complete. At 5AM Tuesday, we will turn off the exhaust and shut the hall door. I can do this if Lawrence is willing to allow it. Robert and his crew will then monitor VESDA levels to ensure that we can run the experiment without issue. If the levels remain negligible, we will consider the test complete and turn the heaters off around noon Tuesday. If we are not quite sure, we could possibly continue until the end of day shift before turning off.

Please comment if you think this plan works or does not.
-Don

Donald Jones
Hall A/C Staff Scientist
Jefferson Lab
Newport News, VA
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