Re: Muon-On-Request

[Michael Barnes <barnes@triumf.ca>]

Dear Francoise,

I am trying hard to remember all the details.... I think the cables you
describe are the wrong ones; the "lemo" type cable which comes from the
star ground and goes in the hole in the back door is the 12V DC supply
which connects to each of the power supply driver boxes.

There should be a BNC type cable (or maybe this was replaced with a lemo
type cable in the summer) which comes from the TRIUMF TTL splitter and
connects to the panel at the back of each cabinet.
When we had the beam pipe and 4 cabinets at TRIUMF (i.e. well before we
made the TRIUMF TTL splitter box) we had 4 long BNC cables (which were
from PSI), which ran from the Boston splitter box, to each cabinet. It was
at this stage that Gary and I added another 9ns cable to each of the HV
cabinets (I am reasonably sure, but not perfectly sure, that this 9ns was
added outside of the cabinet).
My memory is bad re the next part of the story, i.e. following the
manufacture of the TRIUMF TTL splitter/over current detection box. This
splitter was designed to be near the 4 cabinets; hence there was only one
long cable TO this splitter box. I cannot recall the situation at PSI from
when I assisted in the summer to re-commission the kicker: did we keep 4
long cables coming out of the TRIUMF splitter box to the cabinets, or were
these replaced with 4 shorter cables (the most likely I would think). If
the 4 long cables, from the splitter to the cabinets, no longer exist then
the 9ns difference in delay between the HV and MV cabinets is probably
also removed. The only real way to tell is your timing measurements at the
capacitive pickups (without Anatoly's integrators connected). I would try
and use the same probe for all the timing measurements.

Cheers,
Mike

> Dear Mike,
>
>>
>>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).
>>
>
> To be sure that we are speaking about the right cable, I
> have seen external cables starting from the "hole" in the
> back door (meaning not plugged to anything there, just
> sticking out) and reaching again the cabinet just near the
> ground star place, on the external brass plate. The visible
> connector (outside) is a Fischer type. The cable is the
> so-called lemo one. I checked each of the cables. Indeed, it
> seems that the external cables for HV1 and HV2 are longer
> than for MV1 and MV2. But I can not see that there is nearly
> 2m more.
>
> However, there is only one cabinet (HV2) which has the full
> length made of two cables. All other cabinets are having
> only one, more or less long, cable. Thus, we will be able to
> reverse the situation only by cutting the longer cable and
> adding a connector. It is simple, but will require some
> parts, time, and work in a later date.
>
>
> Let me know if I am going in the right direction. My other
> comment is that I was trying to trace the cable inside the
> cabinet. However, in the actual position, the doors can open,
> but not fully. Thus, one can not remove the cover plate of
> the electronics part with physically disconnect the
> door. This to say that I have no idea where the cables are
> going inside the electronic part of the kicker.
>
> Best regards,
>
> Francoise
>
>