RE: Muon-On-Request

[Mulhauser Francoise <francoise.mulhauser@psi.ch>]

Dear Mike,

We discussed a little bit with Peter Kammel the kicker situation in this new
Muon-On-Request mode. We are sending around 30-80kHz of muon in the beam. We
are setting the kicked time to 25mus. After the end of a kicker period, we
wait at least 400ns to allow the next muon to trigger the kicker.

Situation: We are NOT using the magix box as in MuLan. We are sending the
muon entrance counter NIM signal (after the electronic scheme developped by
peter to take into account all requests) to a converter located in the crate
next to the kicker. There, we send the TTL to the kicker directly

Questions:
1- Du to the non periodic function, do you believe that the kicker real
voltage is varying a lot from shot to shot? (Are we in the same situation as
what was planned at the beginning of MuLan run?)
2- When there is no or small amount of beam, the kicker is just waiting for
a next signal to kick. I believe that zero-volt is at zero (with the flat
top circuit there too) and does not fluctuate so much. Basically there, the
kicker is in DC mode. Am I right?
3- The idea of Peter is to send an inhibit signal from the counting room to
the crate in the zone, such that by adding this signal, we could turn the
kicker OFF from the counting room, leaving the "hardware" setting at 12.5kV,
but not sending any pulse. Do you see any reason not to do so?

Comments:
We could reduced the 280ns delay by 10ns, if we change the cable that I used
from the splitter box to the cabinet.

Thanks and best regards

Francoise
-----Original Message-----
From: Michael Barnes
To: Francoise Mulhauser
Cc: barnes@triumf.ca; francoise.mulhauser@psi.ch; kammel@npl.uiuc.edu;
hertzog@uiuc.edu; michael.barnes@triumf.ca; peter.winter@psi.ch;
wait@triumf.ca; carey@bu.edu; anatoly@g2pc1.bu.edu; rmcnabb@uiuc.edu
Sent: 20/11/05 20:15
Subject: Re: Muon-On-Request

Dear Francoise,

This sounds like great progress. The 280ns is slightly longer than I
would
have expected but in the right region.

The 9ns delay that Gary and I originally added to the HV input TTL lines
was to allow for the beam transit time from the input of the upstream
plates to the input of the downstream plates, such that having two sets
of
plates did not result in distortion of the deflection rise or fall. As
you
say, the relative timing of the plates can readily be adjusted by adding
the appropriate length of BNC cable to the TTL cables of, for example,
the
MV cabinets.

Best regards,
Mike

PS: did you have time to check that the 6 spare MOSFET cards are at PSI?

> Dear Mike,
>
> We have made the measurement today. We obtained for each of
> the capacitive pick-up the same delay, within +- 2ns. You
> can say that we have 280ns delay between the TTL input and
> the deflector plate.
>
> Also, we have turned the kicker in the muon on request
> mode. It seems to work well. We are trying to diagnose what
> we see and find way to make sure that there is no "bad"
> pulse.
>
> I am using the Trip monitor to see the capacitive pick-up
> signals in the counting room. One sees nicely the random
> behaviour of the next muon, with the block time of 25mus in
> between.
>
> Best regards
> Francoise
>
>