[Halld] Update on delay for the start of the Fall 16 run

[Alexandre Deur]

Dear Collaborators,

Accelerator updated us this morning on the power supply repair. The estimate given is that the repairs may be done by about November 1st, with a large uncertainty on this date: the power supply company has not yet sent a date for when the new chokes can be available. Furthermore, the cause of the problem is still not identified. Once it is, fixing it may cause further delays. The reason why this is taking longer than the two weeks timescale I mentioned yesterday is because this time four chokes failed, while only one failed during the spring 16 run. 

Shifts are cancelled until October 20th. They are on standby until Nov. 1st, 8am. (Standby means that the shift crew should be close to JLab and ready to come to shift on short notice).

I will send more updates on the situation as they become available. 

Thank you,
 
Alexandre Deur, Hall D Run Coordinator.

RC cell: 757-383-5542
Office Phone: 757-269-7526



----- Original Message -----
> From: "Alexandre Deur" <deurpam at jlab.org>
> To: "halld" <halld at jlab.org>, "gluex-collaboration" <gluex-collaboration at jlab.org>
> Sent: Tuesday, October 4, 2016 10:07:56 AM
> Subject: Delay for the start of the Fall 16 run

> Dear Collaborators,
> 
> There will a delay in start of operations for Hall D due to a power-supply
> problem in accelerator's arc 7. You may remember there was already a
> power-supply incident in one arc during the last run in spring. The problem
> -although of different cause- affects the same type of hardware (a power supply
> choke, a set of two coils acting as current regulator) as the one during the
> Spring 16 incident. It took then 2 weeks to receive a replacement choke from
> the factory. We do not know yet how long the present repair will take, but
> two-weeks gives a timescale. The machine may continue its preparation for the
> run, and Hall A may go on with its program at pass 4 if a choke is borrowed
> from a higher arc, as was done last time. Alternatively, the whole accelerator
> operation may be postponed. The decision should be taken shortly.
> 
> As far as Hall D is concerned, it is safe to assume that the start of its run
> will be delayed by at least a week. All shifts are canceled until Thursday
> October 13 at 8:00am. A notice will be sent soon regarding the next shifts. The
> daily preparation meetings are cancelled until Friday.
> 
> In lieu of tomorrow's preparation meeting, I will send an update on this
> incident.
> 
> Thank you,
> 
> Alexandre Deur, Hall D Run Coordinator.
> 
> RC cell: 757-383-5542
> Office Phone: 757-269-7526