I have attached a pdf of a series of slides with some multiplicity and hit pattern plots on, also a list of cuts. As well as this I looked at how many 'good hits' (explained in pdf) I am getting per event.

Before Christmas I found that the code was not clearing the raw arrays read in by MIDAS and so unless a new piece of data filled the array channel number the data from the last event was being read into the next event too. It was only clearing the 'data(i) arrays which is what the data is unpacked as. I have now got it clearing both so data is not read in for multiple events.

Things have been running smoothly from 4 pm to midnight.

Reading in FC0 = 120-130 epA

Total trigger (accepted trigger) = 7500 (4000) Hz

Gas temperature has dropped from 30 to 22 deg C (due to evening cooling of experimental hall?). As a consequence, pressure has dropped by 0.2% (current value 249.8 torr).

Runs during this shift: 87, 88, 89, 90, and 91 (still running).

Runs 87-90 have been analyzed with sorting code.

Good night

 We have been running smoothly all night. Only problem is that the DAQ occasionally does not start properly after a stop-go. The dead-time goes to nearly 100%. This happened twice in the night,. and a second stop-go did the trick. Needs looking at.

We are going to stop now and (a) check the tune properly and (b) retune if necessary and then carry on the same energy. There is not really evidence in the data of the structure we are looking for, so we need to carry on at this energy for a while. This process will take 6 hours or so

MAB

 I have attached some single strip energy vs time plots to show that the structure seen in the collective E vs t plots is in each strip. 

Attachments 1 and 2 show two different strips in S2-2 with no cuts. You can see that the 3 loci are different to one another in the single strips as well as in the combined S2-2 E vs t plot shown in attachment 3. Attachement 3 is plotted after applying the following cuts: equal energy in the front and back of each detector, low energy cut, must be a hit in each detector, multiplicity must be greater than 3. The 3 different loci are a beam pulse apart. The energy cal is 40keV/chan. 

Attachments 4 and 5 show energy vs time for single strips in S2-1 with no cuts. Attachment 6 shows the combined front strips in S2-1 after the same cuts as above for the combined S2-2 plot have been applied. Now there are 2 loci in the same beam pulse which are still there after the cuts. Not sure what the second line is. The energy cal in attachment 6 is 80keV/chan.

Attached plot shows rate of pressure increase in ~2l volume upstream of TUDA with Ni window #2 installed on reentrant flange. Comparison between

a)pumping out TUDA and 2l volume, and

b) filling TUDA with ~340mbar of He and pumping out 2l volume.

In both cases, 2l volume isolated from pumps at start.

Gradients are comparible, hence no detectable He leak through window.

Will repeat with other windows and blank flange tomorrow.

09.20 TUDA2.PNG5 1.04E-06Torr
      See attachments 1 & 2 for EPICS log of pump down and overnight
      pumping

09.37 Vent TUDA

14.00 S2-2 and W positions swapped
      Coolant loop disconnected - needs to be re-tested

15.08 Time to 250mTorr ~12m
      Time from 250mTorr to 4.75-05Torr ~28m
      See attachment 3

15.36 FTS RS44 set point +5.5 deg C

17.00 TUDA2.PNG5 4.5E-06Torr

17.14 FTS RS44 set point +22 deg C

17.31 TUDA2.PNG5 6.2E-06Torr

Cryo closed and turbo pump switched off. Will monitor leak-in rate
from good vacuum (< 1E-05 Torr) overnight. 
     

York W detector 2635-19

1037um

 Update: 

W decided at 8.00 to stop, check the tune, retune and get back going. This has nearly, finished but it is a very long process indeed - note for future - this takes AT LEAST 12 hours, if one is systematic about it.

We tested the tune as it was - it was OK, (90% transmission or so acdording to a straight ratio of the cups) but there are a fair bit on the 4mm collimator. 

Marco then tuned, and improved it with a high intensity tune, reduced the rate on the collimator by at least a factor of 5 - maybe more. Good position on scintillator - see photo below.

We have since pumped out and run several tests with the window in, but no gas: (1) 10mm collimator on first target ladder, nothing on second - transmission was about the same, measured the same way. Rate similar to same test we did a couple of days ago. (2) 5mm collimator and blank second target - result about the same. (3) 5mm collimator and scintillator in - photo below. Beam spot blew up a bit compared with no gas. See below. (4) 5mm collimator and PD2 (5) 5mm collimator and blank. Ran this to disk. and (6) CH2 target. This made no sense and we got a lot of horrible ate of this so we stopped it.

We saw noise in S2-2 when we had no gas. It was bad - 1200Hz with no beam - all from S2-2. When we put gas in, it all went away! We suspect that it was a gauge that we disconnected, perhaps.

Waiting for beam, as buncher has now tripped.

Note that full cycle (pump, flush, vent, tune, flush, pump H2) - with all the tests as you go along, took 12 hours!

The pictures below are tunes without and with the window. From Mikes iphone. !

The TUDA @ ISAC-II grounding test was successfully completed this am
per work permit 2011-04-12-2.

We measured 60V/0mA (with PSU) and 0.385MOhm with a Digital multimeter.

The TUDA grounding test is now complete. The TUDA ground breaker switch
is now closed and locked. The lockout key has been returned to ISAC Ops.

11.27 TUDA2.PNG5 6.27E-07Torr

11.30 Vent to install experiment configuration and coolant loop

14.00 Experiment configuration (https://elog.triumf.ca/Tuda/S1287/2)
      installed.

      Coolant loop installed.

      FTS RS44LT recirculating chiller coolant (ethanol) drained from
      reservoir and returned to 5-litre red plastic gerry can - now stored
      in Pat Walden's N. Cupboard in the ISAC-I hall.

      FTS RS44LT coolant now 7-stage filtered water from ISAC-II cleaner's
      room (on the corridor to rooms 148 & 154).
      
      FTS RS44LT Set Low (SL) parameter changed from -43 deg C to +5 deg C

15.00 Test of coolant loop in air - no gross leaks

15.30 Commence pump down to test coolant loop at vacuum

      See attachment 1 - time from turbo ON to 5.0E-5Torr ~18m

      FTS RS44 switched on ~25' before datum - set point +5.5 deg C
      TUDA.PNG5 pressure continues to decrease - coolant loop appears
      to be OK

16.55 FTS RS44 temp +5.8 deg C
      TUDA2.PNG5 9.24E-06Torr

      FTS RS44 set point +22 deg C

      Will leave pumping overnight with FTS RS44 off

10.02 See attachment 1 for overnight EPICS log of TUDA2.CG5
      Downstream flange secured by four bolts
      Current pressure 1.07Torr - rate of increase ~0.2 Torr/5h

11.30 TUDA chamber pumped down to ~800mbar
      Downstream flange bolts removed - no change in pressure observed
      N2 bottle connected to TUDA vent valve - to vent and (hopefully)
      exceed atmospheric pressure forcing downstream flange to move open
      Pressure measured using MKS Baratron 1000Torr gauge

      Result - pressure increased from 800 to ~1000mbar in ~45s
      TUDA chamber pressure did not noticably exceed atmospheric
      pressure and there was no obvious movement of downstream flange.
      Gas could be felt escaping from sides of downstream flange.

      Conclude - contact with downstream flange O-ring failed at, or near,
      atmospheric pressure - this prevented buildup in excess of atmospheric
      pressure

11.50 Installed:

      preamp services (+/-15V preamp power, +/- preamp test inputs) - 10-way IDC
      ribbon cables

      detector HT - SMC/BNC cabling

      preamp signals - 34-way IDC twist-n-flat ribbon cables

      preamp thermocouple attached to an S2-1 preamplifier

15.00 Time to 250mTorr ~14m
      Time from 250mTorr to 4.75E-5Torr ~45m
      See attachment 2

16.04 FTS RS44 set point +5.5 deg C

16.21 FTS RS44 temperature +5.6 deg C

17.12 TUDA2.PNG5 8.2E-06Torr
      FTS RS44 temperature +5.8 deg C
      Preamp thermocouple +8 deg C

17.13 +/-15V preamp power ON

17.18 Preamp thermocouple +14 deg C
      TUDA2.PNG5 8.0E-06Torr

17.23 Preamp thermocouple +14 deg C
      TUDA2.PNG5 7.9E-06Torr

17.28 Preamp thermocouple +15 deg C
      TUDA2.PNG5 7.7E-06Torr

17.43 Preamp thermocouple +15 deg C
      TUDA2.PNG5 7.0E-06Torr

CAEN SY403 HV mainframe

      Channel HT Detector Bias  I_L
                           (V) (uA)

          1    1   S2-1   -130  -0.03
          2    2   S2-2   -130  -0.06
          3    3   W      -250  -0.02
          4    4   PD      -30  -0.03

      Low leakage currents as expected - no evidence of high resistance
      shorts

      All other channels set to 0V

+/-15V PSUs

      #1 +15V/0A -15V/0A (MSL type W preamp not installed)
      #2 +15V/1.65A -15V/0.65A (2x MSL type S2 + 1x 16ch PD preamp units)

17.58 Preamp thermocouple +13 deg C
      TUDA2.PNG5 6.3E-06Torr

18.13 Preamp thermocouple +12 deg C
      TUDA2.PNG5 5.8-06Torr

18.29 Preamp thermocouple +12 deg C
      TUDA2.PNG5 5.3-06Torr

18.32 +/-15V preamp power OFF
      FTS RS44 set point +21 deg C

18.39 Cryo gate valve closed
      Turbo off and isolated
      4x bolts securing downstream flange removed

      Repeat yesterday's leak-in test (bolts removed)

    

Run139

Started 19:05:03
Stopped 20:36:36

Rates were reaching well above 8500, ops were measuring 160 epa on FC0 so they decreased it to 120 epa before starting next run.

Run 140

Started 20:42:12    - Scalers were acting up, stopped the run
Stopped 20:55:50

Run 141

Started 20:56:14
Stopped at 22:50:02

Rates were too low (~4289), ops were measuring 70 epa on FC0, got ops to increase current to 120 epa before starting next run.

Run 142

Started 22:56:34
Stopped 23:32:13

Rates were reaching above 9000 again, ops were reading 150 epa on FC0.  Brought it back down to 115 epa before starting next run.

Run 143

Started 23:36:38 - scalers were acting up, stopped the run
Stopped 23:37:46

Run 144

Started 23:40:17


****submitting summary early in case browser crashes again.  will update with any changes.

For run 123:

Beam outage for ~15 min but not stopping run.

FC0 = 120pA when we got beam back.

We'll let the run go 15 min longer.

Run 125 stopped early because of strange rate values on scalar 1.

Sorted Runs:

Finished 121

122

123

124

The thick carbon target, to be used for background runs for the thick CH2 measurement was supplied by Marek.

He measured it to be 120um thick (with a micrometer), and says it's low density carbon (1.03g/cm3).

The range of a 68 MeV Ne beam in this is 67um.

Range of 16 MeV alphas is 266.5 um.

Nominal detector configuration for S1287 is as follows:


Detector   Tgt Ladder #2
             -Detector      Nominal LAB     Solid
           Distance (cm)    Angles (deg)  Angle (sr)

 S2-1        7.0            9.5-26.4      0.430
 S2-2        28.0           2.4-7.1       0.032

 W           >35.0          0.0-4.1      ~0.020

S2-1 MSL type S2(DS)-500
S2-2 MSL type S2(DS)-500
W    MSL type W(DS)-1000

Hardware installed in TUDA chamber is as follows (listing from
upstream to downstream):

1 Upstream support collar

2 PDs (to monitor Ni window)
  PD preamplifier assembly

3 4mm dia collimator
  CCTV camera?

Target Ladder - Position #1 - 83cm from inner surface of the downstream flange
  5mm dia anti-scatter collimator
  PDs (to monitor 197Au RBS)

Target Ladder - Position #2 - 75cm from inner surface of the downstream flange
  10mm & 3mm dia tuning apertures, ZnS, PDs, (CH2)n targets

4 S2-1 DSSSD
  S2 preamplifier assembly

5 S2-2 DSSSD
  S2 preamplifier

6 W DSSSD
  W preamplifier assembly (to be shipped to TRIUMF)

7 Faraday Cup

8 Downstream 4-vane monitor (not used)

Detector mounts will be within +/-5mm of their nominal positions.

Continuation of yesterday's test with c. 300mBar of He
in the TUDA chamber.

      Bourdon    MKS        S2 preamp
                 Baratron   Thermocouple
      (mBar)     (Torr)     (deg C)

09.45 300        222.8      +21
10.44 300        222.9      +21
11.48 300        223.1      +22

11.49 FTS RS44 set point +22.0 deg C
      +/-15V preamp power ON

12.01 300        223.4      +26  FTS RS44 @ set point
12.31 300        223.7      +26
13.00 300        223.9      +26

13.01 FTS RS44 set point +15.0 deg C

13.11 300        223.4      +21  FTS RS44 @ set point
13.41 300        223.0      +22
14.11 300        222.9      +22
15.14 300        222.9      +22
16.11 300        222.9      +22
17.11 300        223.1      +22
18.16 300        223.1      +22
19.10 300        223.2      +22
20.19 300        223.1      +21

20.20 +/-15V preamp power OFF
      FTS RS44 set point +20 deg C

20.25 Bolts securing downstream flange re-installed
      - finger tight only

20.45 Vent TUDA chamber to air, i.e. chamber contains He & air

See attachment 1. Conclude that the preamps can be operated with
the FTS RS44 recirculating chiller set point +15 deg C with 300mBar
of He. The S2-1 preamplifier thermocouple indicates that the preamplifiers
are operating at about ambient temperature with little apparent effect
on gas pressure.

N.B. For vacuum operation, the FTS RS44 set point should be +5.5 deg C



Pulser tests

BNC PB-4 settings:
Amplitude 90,000 x5 attenuator IN
frequency 266Hz
delay MIN
tail pulse
t_r 50ns tau_d 1000us
INT ref 
polarity + (for p+n junction strips, - for n+n ohmic strips)

All ADC & TDC channels OK

ADCs

               FWHM
Detector       (ch)   (keV)

S2-1 p+n #23   1.6    30
S2-1 n+n #8    1.6    30
S2-2 p+n #23   1.7    15
S2-2 n+n #8    1.8    16
W p+n #8       2.2    19      } using signals
W n+n #8       4.3    37      } from S2-2 preamps
PD #0          1.7    81

TDCs (0.8ns/ch)

               Centroid  FWHM
Detector       (ch)      (ch)

S2-1 p+n #23   245        1.4
S2-1 n+n #8    254        1.9
S2-2 p+n #23   253        1.7
S2-2 n+n #8    260        1.8
W p+n #8       254        1.8
W n+n #8       266        1.2
PD #0          233        1.6

 Wednesday morning:

4 new windows were tested last night. 2 very good.

Now venting to install and test Faraday cup, install and test camera.

Remaining to do list:

Before beam - 

 beamline on SEBT back in and pumping upstream section

(measure C and C/Au target thicknesses if time)

replace 4mm collimator on plate with 10 mm for tuning

confirm PD0 problem just connector

install detector shields and pump down

walk round TUDA and check no grounding compromises

Before running -

runplan

procedures tick list for H2

runlog and detector current list

exclusion zone and Al plate before running H2

Summary at start of run

Read through the runbook and end of run summar and the situation appears to be:

1. The check of the tune showed it was OK, although a bit of beam (or halo) clipping 4mm collimator

2. There are some changes to the gas filling scheme - Jamie should be present for the next one.

3. Evidence that the gas pressure is dropping slowly - need to watch this

4. Trigger is Coinc.OR.SS_2.OR.PD.  Rate at this is 200/s at 4epA (50/50 Coinc and S2_2)

5. Suggestion we could increase the beam a factor of two to get back to the same coinc rate.

Analysis.  Looking at the rates I see:

Running at 66 pnA and see about 4,000/s triggers and 3,200/s accepts. Scaler 9 over 40,000/s.

Looking back in run book the max trigger accept rate we see is about 3,800/s.  Could double beam and gain only

modest increase on accepted rate, but at cost of faster damage of detector.  Suggest we run

like this for a bit and make sure all is well.

Took a look through the spectra.  All ADCs OK, but no TDC signals.  Checked past saved runs.  There up

to run 98.  The next saved on disc is run 104 and they aren't there.  Nor in any saved runs after this.

Looked at electronics and reason clear as the module providing the TDC trigger (lower section of a

429 unit) has no input.  Eventually determined that it would make sense if this unit was operating

in 2 x 8 mode rather than what it is currently set on (4x4).  Switched this over and now working OK.

Assume this was changed inadvertently during all the work on the chamber yesterday.

0300.  Running again and all ADC and TDC spectra make sense.  Off for a cup of tea.

Handover from last shift was...

1. Running at 4.11 MeV/u at about 15enA (5+)

2. Would like to take more beam but already at situation where deadtime about 50%.  They have been raising thresholds on the inner strips of S2-1 to try and cure that, but it doesn't appear to have helped.

3. There is a sort of the past runs ongoing to use the counts in spectrum 4200 (coincidences) to estimate when there is enough data at this energy to move to the next.

Analysis:

Firstly, the locus being looked at in the S2-1 vs S2-2 to make this judgement cant be right.  There are already thousands of counts in this in a replay of a one hour run  Jamie's estimates in the run proposal were for 1,000 in 12 hours at 10**8/s.  We are currently at 20% of that beam intensity and the deadlime is about 50%, so should be seeing 10 counts in one hour.  The data must be somewhere else in the plot.  My guess is that the intense locus is elastic/inelastic scattering coincidences.  If this is the case then it maybe we have an issue in that these may be what is dominating the rate and it will not be possible to get rid of them from the trigger.

Looking at the S2-1 energy spectra, it looks like the raised threshold is cutting into potential data (maybe Alex who knows from the MC what energy the data extends down to should look at this and check).  The high trigger ratemust be from another channel.

Actions for this shift

1. With two people on shift and a requirement that we need two down in the area at all times, I don't think chasing thresholds is viable.  This will have to be left to the day shift.

2. Should continue the sorts so that we have the spectra available to make rate estimates once we know what we are looking for.

3. Should look at the sort code to see what calibrations are being used and so determine where on the coincidence spectrum the data should lie.

A summary of online sort programs can be found at:

~/S1287/sort/README

Program sort2.f remains to be completed.

VME and sort spectra titles can be found in directory:

~/S1287/titles

A summary of the calibration procedure can be found at:

~/S1287/calibration/README