Re: Muon-On-Request

[Michael Barnes <barnes@triumf.ca>]

Dear Francoise,

Thanks for the update, and congratulations.

The 9ns timing difference between the HV and MV plates is, if I remember
correctly, an extra length of (TTL) cable OUTside each of the HV cabinets.
Hence, if my memory is correct, the two 9ns lengths of cables an easily be
removed from the HV cabinets and added to the TTL cables on the outside of
the MV cabinets (I think the 9ns was a special length made up in the
TRIUMF electronics shop and probably does not have a delay marked on it
--- but each of these 9ns coax would be approx 1.8m long).

Hope this helps.

Good luck,
Mike

> Dear Mike and co,
>
> This afternoon, we turned on the kicker, after having
> cleaned it. Everything behave properly and the kicker is
> kicking well.
>
> We then performed the measurement described below.
>
>>
>>> Peter Winter can confirm the overall delay through the TRIUMF TTL
>>> splitter
>>> box, controls, etc to the pulse rise.  To do this I would recommend the
>>> following measurement  procedure:
>>> 1) Use 2 high impedance (e.g. x10) probes and deskew them both (to have
>>> the
>>> same timing) at the input to the TRIUMF TTL splitter box;
>>> 2) Use one of these high impedance probes as a trigger for the scope,
>>> connect
>>> the other probe directly on the output of one of the capacitive
>>> pick-ups on
>>> the beam tank (by directly I mean WITHOUT Anatoly's box --- this box
>>> includes
>>> an "integrator" and delay cable so would distort the timing
>>> measurement);
>>> 3) Note the delay between the rise of the TTL signal and the rise of
>>> the
>>> deflector plate voltage.
>>
>>We will check the delays together before we switch to this mode.
>>>
>
> We had two probes, that had 3ns delay (we took it into
> account). We obtained a delay between the input of the TTL
> splitter box and the output of the capacitive pick-up,
> located on the bottom downstream (close to the MV1 cabinet)
> which is 280ns.
>
>
>>>
>>> NOTE: we have deliberately set-up the timing of HV1 & HV2 to be 9ns
>>> delayed
>>> with respect to the timing of  MV1 & MV2: this is to allow for the beam
>>> propagation delay from the input of plates MV1 & MV2 to the input of
>>> plates
>>> HV1 & HV2. The 9ns delay also ensures that the beam "sees" the same
>>> pulse
>>> width at both sets of deflector plates. You should be able to see this
>>> 9ns
>>> delay depending on which end of the beam pipe you make the timing
>>> measurement
>>> at. The 9ns delay is achieved by adding 9ns worth of 50R coaxial cables
>>> to
>>> the inputs of cabinets HV1 & HV2.
>>>
>>
>
> I just realized that this 9ns delay you set up is
> unfortunately WRONG. Why? Due to the new kicker position in
> the beamline, namely kicker first, separator second, we HAD
> to turn the kicker by 180 degrees. Therefore, the HV1 and HV2
> plates are seen the beam first, and MV1, MV2 are
> downstream. So the additional 9ns increases the difference
> between the front and the back of the kicker, thus maybe add
> some effects.
>
> Ron, Dave, Rob, and other, please look at this systematics
> effect for 2005 measurements!
>
>
>
> Last but not least, Anatoly's question about the fan:
>
>>It's as I remember, all fans (with no exception) blow cool air into
>>cabinets.
>
> NO this is a wrong statement. Mike is right.
>
>> Hello Anatoly,
>>
>> I believe, from memory, that the fan on the bottom of each of cabinets
>> HV1 & HV2 blow air OUT of the cabinet (rather than into the cabinet)
>> -- I believe we did this to ensure dust from the floor was not blown
>> into the cabinet.
>
> We checked it. Indeed, all the fans located on the doors are
> blowing air inside the cabinets. However, the fans located
> on the bottom of HV1, MV1, and HV2, are blowing air OUT.
>
> Best regards
>
> Francoise
>
>