RE: Kicker news (good)

[Robert Carey <carey@buphy.bu.edu>]

Dear guys,
    If you want to resinsert the collimator and they still have the same
pins they came with 3 years ago, you might consider replacing the pins 
another set whose fit can be made a bit more snug. The pins are not pricey.

 					Rob


On Fri, 2 Dec 2005, Mulhauser Francoise wrote:

> Dear Brendan and Peter,
>
> Whah.... This is great and very good news.
>
> Yesterday night, during our telephone discussion, I was at the same time
> very confident that the collimator HAS to be the faulty guy, and could not
> believe that it would be so easy.
>
> Your decisions are the most efficient and you should continue to pump.
> Please wait until the pressure is down to 5x10-5mbar to start the separator
> and kicker. As already mentionned, you can open manually the valve between
> the separator and kicker when pressure is low 10-4 (ask M.Koller to tell you
> where to look for it. It is in a rack, one floor below the magnet
> powersupply.)
>
> ps. Brendan, I did not get your email. I got only the reply from Mike.
> Something is strange in your mailing list.
>
> Best regards
> Francoise
>
> -----Original Message-----
> From: Michael Barnes
> To: kiburg@npl.uiuc.edu
> Cc: Gary Wait; Peter Winter; Michael Barnes; Mulhauser Francoise;
> kammel@npl.uiuc.edu; hertzog@uiuc.edu; michael.barnes@triumf.ca; Robert M
> Carey; Anatoly Gafarov; rmcnabb@uiuc.edu; claude.petitjean@psi.ch
> Sent: 02/12/05 11:31
> Subject: Re: Kicker news (good)
>
> Dear Brendan and Peter,
>
> Congratulations: I am very pleased that the breakdown is caused by
> something as simple as the collimator falling out of place and that it
> is
> not a "wear out" mechanism of the Fischer socket.
> Look forward to hearing that everything is confirmed to be working
> later.
>
> Re card 13: please check the backplane to ensure that the connections to
> the fast grading capacitors are not shorting against the terminals on
> the
> back of the blue connector (this can easily occur during voltage grading
> and would cause the red LED not to be lit). Otherwise, as we concluded
> yesterday, it is probably the fibre optic cable.
>
> Best regards,
> Mike
>
>> 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
>>
>>
>