Re: Back in action

[Gary D Wait <wait@triumf.ca>]

Hi ALL
If Mike is right about a short on the backplane ( I hope he is right) at 
DN-13 then there is no need to send cards to me.
Regarding air filters, I recommend that none be installed on the doors. 
Mike and I tried various air filters a few years ago and determined that 
the air flow was severely restricted, even with a filter that was quite 
open and porous.
Regards
Gary

Gary D Wait wrote:

> Brendan and Peter
> Nice work!!
> I am concerned about DN-13. I think the fiber optic cable might be 
> intermittent and should be replaced so that you can run at full 
> voltage with more confidence. Please send the cards that you replaced 
> to my attention at TRIUMF and I will check them out.
>
> TRIUMF
> 4004 Wesbrook Mall
> Vancouver B.C., Canada
> V6T 5L8
>
> Regards
> Gary Wait
>
> Brendan Kiburg wrote:
>
>> Hello again, We have more good news to report.  We recleaned the 
>> fischer and made sure
>> it had silicon paste.  We replaced DN-13 and the RED LED was working
>> again.  The beamline produced an excellent vacuum in a very short 
>> time (~4
>> hours) and so we were able to start testing the muon on request mode
>> around 4 pm.  We have now verified that the kicker is working 
>> properly in
>> vacuum, with the pickup signals as well as with our detectors.
>>
>> There is really every indication that we have resolved this issue and
>> restored the kicker to a working state.  We are now taking production
>> kicked mu+ data only 1 shift after we removed the vacuum to begin 
>> repairs,
>> so we are quite happy about that.  We plan to monitor the kicker signals
>> and make occasional accesses to verify the LED status and display
>> voltages.
>>
>> Thanks again for all of the external support.  Please feel free to 
>> follow
>> any future developments on the kicker as well as the mucap experiment 
>> via
>> our electronic logbook on http://kaon.physics.berkeley.edu:8080/run9 .
>> Best regards,
>>
>> Brendan and Peter
>>
>> On Fri, 2 Dec 2005, Peter Kammel wrote:
>>
>>  
>>
>>> Dear Peter, dear Brendan,
>>>
>>> Congratulations for your findings. I am very impressed how you
>>> worked out a thoughtful plan, communicated with the experts on every
>>> details and made the right decisions. That was not so easy, considering
>>> that you are already exhausted by your other run duties.
>>>
>>> Many thanks to all the remote experts for their enormous help and
>>> careful thinking up to 3AM. This was really excellent teamwork.
>>>
>>> I don't see why we would need the collimator for MuCap.
>>>
>>> Good luck
>>>
>>> Peter
>>>
>>>
>>>
>>> On Fri, 2 Dec 2005, Brendan Kiburg wrote:
>>>
>>>   
>>>
>>>> Dear Colleagues,
>>>>  This morning we discussed with the hallendienst our plans.  They
>>>> explained that due to time constraint, we should not first look in the
>>>> top/down access ports, but rather we should move or wait until 
>>>> Monday.  We
>>>> decided to move and they disconnected the kicker.
>>>>
>>>>  As the upstream bellow was removed, the SU identified that the
>>>> collimator was no longer in position.  He said that it was at 
>>>> already at
>>>> an angle relative to vertical (~45 degrees), and that it fell
>>>> further when they removed the bellows. 
>>>>  Based on what the SU told us, we fully believe the collimator
>>>> was in electrical contact with the upstream deflector plate and the
>>>> beampipe at the time of opening.  We remeasured the resistance 
>>>> between the
>>>> fischer connector in HV1 and ground and obtained >20 MOhm , so the 
>>>> short
>>>> appeared to be gone.  At air, we reconnected the power and ground and
>>>> turned on HV2 as a control in the fixed frequency mode.  We
>>>> then ramped up the voltage on HV1 and found no breakdown and we 
>>>> were able
>>>> to achieve +9 kV on HV2 and -9 kV on HV1. We note that
>>>> there was no Red LED on card 13, but we concluded yesterday this is a
>>>> problem with the optical fiber and not a problem related to the
>>>> breakdown.  This was our reasoning for stopping at 9 kV for the time
>>>> being.
>>>>
>>>>  As a result of our findings, we believe there is clear evidence the
>>>> collimator was responsible for the breakdown.  We have removed the
>>>> collimator, as there was damage to the nylon ends inserted in the set
>>>> screws.  We made the working decision to return to vacuum without
>>>> inserting the collimator, but we have left open the option of 
>>>> reinserting
>>>> it as early as next wednesday if we see significant evidence that 
>>>> we need
>>>> it for beam quality.
>>>>
>>>>  We are currently pumping the beamline, which will take on the 
>>>> order of 8
>>>> hours.  We can then verify that everything still works, and 
>>>> continue with
>>>> our measurement program.  If there are any further problems, we will
>>>> communicate them to all of you.  We will send another email later 
>>>> tonight
>>>> when we have verified the repair was succesful.  Thanks for all the
>>>> efforts and communication; we appreciate it.
>>>>
>>>> With guarded optimism,
>>>>
>>>> Brendan and Peter
>>>>
>>>>     
>>>
>>> Peter Kammel  /  pkammel@uiuc.edu
>>> Department of Physics, Loomis Laboratory
>>> University of Illinois at Urbana-Champaign
>>> 1110 West Green Street, Urbana, IL 61801 Tel (217) 333-5424 / Fax 
>>> (217) 333-1215  
>>>
>>>   
>>
>>
>>  
>>
>
>