[Halld] Status of the run

[Eugene Chudakov]

An update from the today's MCC meeting:

They believe they have gained 4 days in the schedule. Now, they expect
that the accelerator will start on Mar 22 and physics would start
about Mar 26.  Still, there is plenty of uncertainty.

The first transformer is expected to be delivered tomorrow and its
installation would start on Monday.

Eugene

On Thu, 8 Mar 2018, Eugene Chudakov wrote:

> More updates:
>
> The Lab's preferred plan is:
>
> Finish the planned run duration (18 beam days left) at the full
> energy.  The cutoff would be April 16. Expanding from Apr 6 to Apr 16
> would only impact the power bill for April. The beam delivery to the
> halls would start about March 29.
>
> The plans obviously depend on the delivery and installation of the new
> transformers and could be reconsidered if problems occur on that
> path.
>
> Eugene
>
> On Thu, 8 Mar 2018, Eugene Chudakov wrote:
>
>> Update from the today's 8:00 MCC meeting:
>> 
>> a) The option of running with the single transformer is off the table.
>> The oil probe from this transformer showed signs of degradation of the
>> insulation.
>> 
>> b) The Arne's time estimate: accelerator start by Mar 26, a few
>> days needed for tuning, about 1 week of hall operations before Apr 6.
>> 
>> c) A plan to run at 1 GeV/pass will be considered. Such a run may start
>> by the end of the next week. I am not aware of PAC-approved beam time
>> at this energy.
>> 
>> Eugene
>> 
>> On Wed, 7 Mar 2018, Eugene Chudakov wrote:
>> 
>>> You might have already heard or read in the JLab Communication about
>>> the run status. Let me repeat what we heard at 1:30 MCC meeting. On
>>> Monday one of the 2 transformers supporting the CHL-1 failed. No other
>>> damage has been detected. The CHL-1 is at 4K now.  Potentially, a
>>> single transformer may be able to support steady running at 2K. It is
>>> unclear that it could support transients.
>>> 
>>> Two scenarios are considered:
>>> 
>>> - A quick (1 week?) recovery using the single transformer. Tests are
>>> planned for this Friday or so. However, it is considered a risky path,
>>> not very likely to be taken.
>>> 
>>> - Procurement and installation of 2 new transformers (perhaps, getting
>>> ready to deliver beam by Mar 23). This activity is under way.
>>> 
>>> The run can be extended till Apr 6 without a great stress to the Lab's
>>> budget. Running beyond that date would change considerably the
>>> electric bill.
>>> 
>>> Meanwhile, Hall D is in restricted access. The solenoid is ramping
>>> down.
>>> 
>>> Eugene
>>> 
>>> 
>> 
>