Scint people at Gran Sasso during this period:
E. Katsavounidis, N. Lu, and C. Peck
Reporter:
C. Peck
The proper reporter for much of this period is Eric since he
understands the present MACRO systems far better that either Nina
or I do. However, he is not formally a shift worker so he is
absolved from writing shift reports. I include at the end of this
report an e-mail from Eric describing the calibration experiences
on Aug 16 and 23.
In general, the state of MACRO is healthy, but with a few aches
and pains in some of her parts. She has a sharp pain in the HV
system for SM1 and a small ache in HV for SM2. The current
symptom is that Emily (the HV monitoring program) regularly emits
messages to people on her MAIL list saying that Mainframe 2 (and
often Mainframe 1, also) isn't responding, and more importantly,
mainframe 1 (SM1 HV) is often found off in the morning. A
synopsis of the situation is:
About 3 1/2 weeks ago there was a power flicker in the tunnel. HV
in SM1 and SM2 were tripped off and we lost CAMAC communication
with both HV systems. Investigations showed that circuits in the
HV controller cards (LeCroy 1442) associated with serial control
communication had failed in SM1 and SM2. It should be noted that
these circuits (FET's, open collector transistors and TTL inputs)
are all connected by long unshielded wires from the CAMAC
interface card to the 1442 and between the 1442 cards on SM1 and
SM2. There are no protective clamping diodes on these wires in
the 1442 and I speculate that the failures are due to transient
inductive or capacitive pulses from the UNPROTECTED power lines
driving lights, fans, motors, etc in the tunnel. I believe that
replacing all of the present cabling described above with twisted
pair cables or, better yet, shielded cables would be a good idea.
Paolo Saggese is taking steps to do this.
At present we have no replacement parts for the broken FET's in
the two 1442's and a Camac controller is connected only to SM1.
This explains why EMILY complains about no response from SM2.
However, there is still some intermittent problem with the SM1
1442 (or the CAMAC interface, or the crate controller, or ...)
because it sometimes fails to respond also. This problem is not
understood. But with patience and cable moving, it is possible to
set and check the HV on SM1 and SM2. Finally, the spare 1442 card
is broken, awaiting replacement parts from the US.
I'm happy to report that Nina has been successful in making a
monopole LED calibration program run. On Aug 23 during
calibrations, she successfully made red ligjhts blink on a
collection of SMT LI's (including the new attico version of the
SMT) in SM 2 and 3. The data will be analysed soon I hope. Nina
is now working on the calibration programs for the WFD TDC/ADC.
Peck did work to understand the reason that 3B01 has the highest
rate of SMT's in the detector (forgetting about all of the
cables that have been unplugged at the SMT because of high
rates!) The yellow light indicating activity on 3B01-1 is very
solidly turned on. He soon became an expert in "finding" the reason for the
high rate, having done so six or eight times. The last time,
however, has stuck and the problem is either the PMT or the base
on the PMT in 3B01-11. This is easily verified by unplugging the
HV at the tank from 3b01-10 only (the yellow light stays on).
Unplugging the HV from 3b01-11 turns off the yellow light. A more
sophisticated set of measurements is described in e-mail to
selected people.
The following is a copy of an e-mail from Eric describing
calibrations on Aug 16 and 23.
Buon Ferragosto a tutti!
_________________________________________________
From: OMNI:.IT.INFN.LNGS.WSGS01::KATSVNDS "Erik Katsavounidis" 25-AUG-1995 13:48:33.87
To: PECK,RONGLU,SAGGESE
CC: GORETTI,KATSVNDS
Subj: Calibrations
Hi all,
I've gone through the last two week's calibration runs at looked at
the data at zero level, i.e., trying to understand if the calibration system
is operational and the collected data useful. The calibration history file
entries for the runs I looked at are:
10717 16-AUG-1995 LED/TDC EK RL SM3/4
* The next two runs may contain uninteresting data since the procedures of
* the laser calibration was unclear.
10719 16-AUG-1995 LASER EK RL SM3/4
10720 16-AUG-1995 LASER EK RL SM3/4
10723 16-AUG-1995 LED/TDC EK RL SM5/6
10724 16-AUG-1995 LASER EK RL SM5/6
10725 16-AUG-1995 LASER EK RL SM3/4
10758 23-AUG-1995 LED/TDC EK RL SM1/2
10759 23-AUG-1995 LASER EK RL SM1/2
10760 23-AUG-1995 LED/MONO EK RL SM2
10761 23-AUG-1995 LED/MONO EK RL SM2
Here are my general remarks:
1)The camac lists used for calibrations (until 16-AUG-95) were not perfectly
OK. Although they were most probably collecting calibration data OK within a
uVax there were not allowing full detector running. I have rebuilt the camac
lists for calibrations starting from the default ones. Besides the two
calibration-dedicated equipments, the only difference among these, is that
streamer tube and WFD equipment readouts are all commented out from the readout.
These camac lists are in VXMACB::$1$DIA0:[SCINTSOFT.CAMAC]GUT18_CAL.LISx
(x=1,2,3)
2)The x-uVAX vetoing scheme needed during calibrations has NOT been verified
to work (Nina has checked the cabling and it is fine). Tests of 16-AUG-95 to
run full (uVAX1,2,3) MACRO while calibrating uvax 2 did not produce useful
data because of problem (1). Tests runs of 23-AUG-95 did not produce data
either most probably because of problem (3). We NEED to run SIMILAR calibration
NEXT WEDNESDAY.
3)LED Calibrations performed on 23-AUG-95 DO NOT have neither the LED bit set
in the SPU, nor the corresponding ERP FAKE BOXes present. I guess this is the
reason why the online logbook has them labeled as NORMAL RUNS. THis is probably
due to a HP PULSER cable that was left unplugged when pulser tests were
performed during last week (or that the main shitchbox in SM3 was off; could
that be??).
4)LASER runs seems to be firing only LOWER MACRO Tanks. I don't know if this
is indeed what the command files tell the acquisition to do. We should
understand if this is simply a change in the input parameters. Nominally,
we've been turning on the lasers prior to starting a run. Maybe we've been
using the wrong switch for the attico; I highly doubt it though. I'm pretty
sure I've seen attico tanks firing during laser runs.
The SM4 ERP FAKE box on laser did fire. Could be a ref PMT problem or some
bad cable.
5)There are tanks where LEDs/LASERs are not firing as many times as they
are expected. This implies a possible problem with the LEDs/LASER/TANK/ERP?
there. Look at DISK$SCRATCH:[MACRO.KATSVNDS]CALIBSUM.TEXT for a
summary of calibrations/problem boxes.
Bye,
--Erik