RE: Muon-On-Request

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

 Dear Mike,

Indeed, I was probably not clear enought.

a) The muon beam has a time structure of between approximately 33us
(30kHz) and 12.5us (80kHz) between muon's.

Yes, when not using the kicker, we have them with this average time spacing.

b) After a muon is detected the following beam is deflected for a time
of
25us (i.e. the deflector plate voltage is switched to a high level for
25us). After the 25us the plate voltage returns to 0V and remains here
for
at least 400ns before returning to a high voltage;

Yes. Once the plate voltage has returned to 0V, we ensure with the 400ns
width that no NEXT muon will come too soon. After the 400ns, the next
incoming muon which hit the scintillator will make the signal high and thus
turn the kicker to high voltage.

c) The duration of time for which the deflector plate voltage is low
(approximately 0V) depends on when the next muon is detected so could be
as short as 400ns and as long as approximately 33us.

Yes, indeed.


>I am not clear what is meant by the following: "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".
>Does "Turn the kicker OFF" mean to hold the deflector plates at,
>ideally,
>0V? (i.e. basically AND a 0V inhibit signal with the muon detection
>signal??). Would you still run muon beam, and take data, in this mode?.
>Would the kicker be in this mode "indefinitely"?.

For the MuCap experiment, we could either run in DC mode (no kicker), with
the beam at approximatively 30kHz and do the off-line pile-up protection. Or
we run in Muon-ON-Request mode with the kicker on. It may happend that we
want to switch from one mode to the other for test purpose on a regular
basis.
Instead of going in the zone and turning the kicker off, we were thinking of
sending an additional inhibit signal when we want to run in DC mode. Thus,
the kicker will be force to stay at 0V, because it would not receive the
next muon.  However, the power supply would still be at 12.5kV.

I hope that my comments are more clear than my earlier questions and that
you can give us your suggestions to run the kicker as safe as possible.

good meeting,
best regards,
Francoise