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