Energy vs Time plots

I updated the monte carlo written by Alex to include time and also created new SRIM tables for 250 Torr rather than 300 Torr. I ran the Monte Carlo for a beam energy of 4.44MeV/u and plotted energy vs time for each detector. It should be noted that there are 2 codes, one for scattering 21Ne(p,p)and one for the reaction 21Ne(p,a) and the number of scattered particles as opposed to the number of reaction products from (p,a) are not what is expected in the data but the energies and timing are.

Attachment 1 shows energy vs time in S2-1 (downstream-heavy ion detector) from the data runs at 4.44Mev/u. Beam pulses are 85ns apart. The cuts on this include: equal energy cuts between the front and back of each detector removing interstrip hits, coincidence hits between S2-1 and S2-2, must be a hit in the front and back of each detector, phi cut so that particles must hit S2-1 and S2-2 at 180 degrees to one another. A feature not shown in the monte carlo is the second weaker line of particles, hitting the detector just after the first stronger line. I am not sure what this is, could be beam scattering off the entrance window or from N gas left over in the chamber?

Attachment 2 shows the same plot (energy vs time) simulated with the monte carlo for scattering reactions and for the (p,a) reaction. This shows that the reaction is dominated by beam scattering from the target H2 gas. The 18F extends to lower energies as shown in the monte carlo and there are some lower energy points in the data  (Att 1) which could correspond to this, however I am not sure whether this is F or beam scattering from the entrance window which also produces an extended range of energies. 

Attachment 3 shows energy vs time data plot in S2-2(upstream - light ion detection), at same energy and with same cuts as for s2-1 in Att 1. Again comparing this to attachment 4 which shows the Monte Carlo calculated energy vs time plot for S2-2 the data is dominated by scattering events. The small number of events which happen after 8.5 Mev (protons will punch through the detector after this) could be alphas. The Monte Carlo shows the alpha particles have a wider energy range than the protons. 

Other plots

I ran a 'gas out' data set to see how much scattering was coming from the entrance window to the chamber. There is no gas out run for 4.44 MeV/u so I used the one at 4.11MeV/u. This shows that there was some scattering from the window getting through the cuts described above, in S2-2 they go no higher than 8 MeV which makes me think it is scattering with protons because of the punch through energy. To check it was from the window I checked a run where there was no target and no window in the chamber and saw nothing after the cuts above. 

Other plots I am looking at include: time(S2-1) vs time (S2-2), energy(S2-1) vs energy(S2-2), energy vs strip for each detector, time of flight difference between S2-1 and S2-2 vs energy difference between two detectors, difference in theta (front strip) vs sum energy of two detectors, time of flight vs energy difference. 

eol

 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.

See attached.

Ran all night OK, currently 14epA, H2 stable, DAQ stable

ISSUES:

1. Analysis of S4200 in offline sort lead to conclusion that specttrum is dominated by protons, 8MeV punchthrough visible??.Not many events at high energies, where Alex MC predicts them to be.

2.Noticed that 3 channels in particular in S2-2 have very high rates. All in same bank - can we raise thresholds?  Strips 34,36,46 in S2-2, we think (from mapping in sort code)

3.  The loci in the E vs T spectrum are (a) still aparrently upside down from what expected and (b) very wide in time. There is also a suspiciously sharp edge to the timing peak. Look at eny E vs T loci in the sort

4.Been sorting over night - nearly caught up.

We looked a run (54) from the first H2 run at 4.4 MeV/u and compared with the current data. The The S4200 spectrum and the E vs T loci look exactly the same.

 OK - summary of events during this shift.

1.TDCs. We have been sorting offline, and we have now established that between run 66 and run 79, the TDC mode was incorrectly set (not in common stop mode) after a DAQ crash causing broad loci in the E vs T spectra and times of the wrong sign. This was corrected from Run 81 onwards. 

2. The offline sort is behaving very badly and many of the sorts run since yesterday to now are wrong. Make sure you (a) sort on a different machine than the DAQ and (b) make sure that the sort is killed each time you start a new sort and (c) make sure that it is sorting the righrt run number.

3.  We have changed the trigger to a coincidence (S2-1 plus S2-2) OR S2-2 on its own OR PD.

4. We have increased the beam rate to about 120 epA and we stay on this. Trigger rate should be about 7K with 4K live time.

5. We will not change energy until early morning tomorrow, at the earliest. we will make a decision during the next two shifts based on what we see in the sort.

Mike

1.TDCs. We have been sorting offline, and we have now established that between run 66 and run 79, the TDC mode
was incorrectly set (not in common stop mode) after a DAQ crash causing broad loci in the E vs T spectra and
times of the wrong sign. This was corrected from Run 81 onwards.

TDC channel 0 (reference channel) should have been recorded in the EbyE data - common stop TDC values
can therefore be calculated offline by switching the egid2logical logical variable csm from TRUE to FALSE.
  
2. The offline sort is behaving very badly and many of the sorts run since yesterday to now are wrong. Make sure
you (a) sort on a different machine than the DAQ and (b) make sure that the sort is killed each time you start a
new sort and (c) make sure that it is sorting the righrt run number.

Amen

 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

 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. !

Buncher problem was resolved around 22:00 (driver module needed to be replaced).
Checked current on FC0 and trigger rate, around 4000 presented. We then started a run, only got 20 acquired,
stoped and restarted a run, then all relevant numbers seemed normal.
The pressure inside TUDA is slowly creeping down (~0.3 torr/h), maybe a small leak in the window. It's not the
hall cooling down, the gas temperature actually rose in the meantime.

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.

Running status

Everything seems to be running OK.  ADC and TDC spectra look OK.  Chamber pressure has stabalised.  Detector leakages stabalised

Beam now up to 60pnA with trigger rate about 4,000/s and accepts about 3,000/s

Have spent some time looking at sorted spectra and put notes in the runbook, along with a copy of an email from Tom with some suggestions.  Need someone who can change the sort programme. The key is probably in getting the plot of Tdiff vs Esum calibrated [Tdiff is time difference between S2-1 and S2-2 signals and Esum is the sum of their energies].  The problem is that the TDC signals have not yet been lined up.  We also need to understand the features we see in the E vs t plots, including the puzzeling feature that one of the loci has its "blob" of events at a different energy than the others.

My feeling is that we should continue to run ast this energy, while continuing to refine the sort to try and confirm we can select out the (a,p) events of interest.

Worth thinking as to whether we should take more beam (it is available.

 All ran smoothly.

As a test, ran for a short period at 1200 midday to run without S2-2 in the trigger. Finished that at 1339.

After discussion with Alison, Alex, Brian, Chris - we decided to change energy to 3.98 MeV/u. This started at 1340.

Pumped out H2, Marco steered with low intensity beam. He optimized on our PD2 with the 3mm collimator, then he observed the spot on the scintillator. He believed (as do I) that it looked as good as it did after the high-intensity tune yesterday. Beam spot blown up a bit, as before, but very well centred. picture from iphone below.

Did a run without gas, then filled, then got going on H2. H2 run started 1730. Thus, 4 hours for beam change and low-intensity tune.

Did analysis of rates/triggers with and without gas - all with 100 epA

                     WITHOUT GAS        WITH GAS

S2-2 all           3000                        3800

PD                   1500                        1900

Coincidence  10                            1800 

S2-1 all           13000                     57000

The trigger (7000 ish) is a sum of the first three of course. Interesting that all the coincidences are gas-"related" - which is good I think. It confirms to me that we should consider, at some point, running on only coincidences in the trigger to cut down the dead time (currently 60% live, 40% dead)

that's it. Jamie checking the spectra, if nothing else in this e-log then they are ok.

Sort started on new data, will run it overnight and compare in the morning with the old sort.

Mike

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

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.

Sarah informed me that Jamie was performing the sorting and saving of spectra differently and didn't know what exactly to do so I will not be performing any sorting.

01:40 Run 144 Stopped

01:45 Run 145 Started

03:43 Run 145 Stopped

Stripper foil changed, still seeing fluctuations so the problem could be in the SC-LINAC

03:57 Run 146 Started

Rate durring run 146 has been a little low, will ask for more at the run change.

05:50 Run 146 Stopped

FC0 averaged 65pA for run146.  Got it back up to 100pA for the next run.

05:54 Run 147 Started

06:15 No beam, lost a SC cavity.  Run 147 stopped

06:42 Beam back.  Run 148 started and stopped due to low scaler 1 reading

06:43 Run 149 Started

07:10 Rate dropped back down to ~4200, FC0 = 60pA.  Stopped run 149, saved and zeroed the histograms

FC0 back up to 100pA

07:13 Run 150 Started

No major problems presented, A pluser walk was performed at the begining of the shift run161 S2-1 front, run162 S2-2 front, run163 S2-1 back and run165 S2-2 back.

Runs 166, 168, 169 are void due to bad scaler reading

Two times the control room reported the dipole magnet tripped but beam was recovered within few minutes. FC0 readings range 150-120epA

S2-1 L. current 17.60uA @ 16:00 and 18.85uA @ 23:10

Beam current dropped to 85 epA at the start of the shift, operator checked for reasons and decided to change
stripper foil. That brought the current back up, but it started decreasing again, so from run to run slits were
gradually opened further to keep FC0 current at about 100 epA.
I forgot the part about saving and clearing the spectra after every run, so runs 171-177 were summed together.

 Energy calibration for S2-2 was done using the pulser data (set 6 of the pulser runs) to calculate the offsets and alpha run R186 to calculate the gains and constant. For S2-1 pulser walkthrough 6 was also used to calculate the offsets and the gains calculated using run 31 which is 21Ne beam scattering from Au/C target. The constants were then calculated by fitting a least squares fit to the alpha peaks from run 186 and the gold scattering peak from run 31 energy vs peak position plot.

TDCs were calibrated with different sources for each detector. For S2-1 the offsets were calculated using the TDC spectra for the 21Ne on Au/C (Run 31) data. For S2-2 the run 23 was used which is a pulser run.

Currently applying equal energy and coincidence cuts to the data and plotting using Monte Carlo to compare to what I am seeing in the data. Plotting things such as Energy in S2-1 vs Energy in S2-2, back strip in S2-1 vs back strip in s2-2, energy sum.

I have sorted the 4.11MeV/u data runs (the ones which had the common stop mode on the TDCs) and applied the following cuts:

1. There must be a hit registered in each side of the detectors.
2. equal energy must be deposited in both sides of the detectors.
3. Low energy cut is applied to each detector.
4. Must have a hit in the TDC for the front strips.
5. Must have multiplicity greater than 3.
6. Must have hits in both S2-1 and S2-2.
7. Particles must hit at 180 degrees to in the detectors. (back spoke cut)

Looking at the back spoke in S2-1 vs back spoke in S2-2 plot cut number 7 should be changed to +/- 3 back strips to ensure no particles are being cut out due to position straggling in the gas.

Plotting S2-2 energy vs time with these cuts gives attachment 1. I need to redo the timing calibration for S2-2 as strip 96 has the wrong offset and the resolution needs to be improved. The protons can be seen clearly as they punch through the detector and around 8MeV. I have also attached as attachment 2 the monte carlo plot for S2-2 at this energy. There are two monte carlo codes one for 21Ne beam scattering and one for the reaction which means the number of each type of event are not correctly proportional, in the data there is far more scattering. Here you can see the protons from ~4-8MeV lying underneath the alpha line. The time spread in the actual data of the proton/alpha line is about 25ns whereas in the monte carlo it is about 10 ns for combined alpha and protons. 

Because the protons will punch through the detector at approx 8MeV I believe that the points after this could be alphas. Attachment 3 shows the projection for the polygon which selects particles after the protons in the energy vs time plot. As can be seen from the energy projection the energy dips where you would expect it to for alphas, however there are some higher energy points and I am not sure what these might be.

I then plotted Energy vs time in S2-1 gating on energy in S2-2 greater than 8.2MeV. This plot is shown in attachment 6. Attachment 4 shows the Monte Carlo simulated energy vs time for 18F in S2-1, with attachment 5 shows simulated energy vs time for scattered 21Ne in S2-1. I plotted these separately as they have the similar timing and so cant be seen separately on the same plot. Here you can see the 21Ne clearly in the data, so some of the protons are depositing more than 8.2 MeV in S2-2. If I change the cut so that the energy in S2-2 must be greater than 9MeV and plot energy vs time for S2-1 again the 21Ne is no longer visible (will not let me attach this file due to capacity so I will attach it in a new elog entry straight after this one). The energy spread of the points in the S2-1 energy vs time plot cut on what could be alphas in S2-2 gives the correct energy spread for 18F in the monte carlo simulated data.

Next:

• Redo timing calibration for S2-2
• Look at gas out run
• Work out how to separate lower energy alphas and protons
• Work out what higher energy points in S2-2 could be.

 Attachment 1 shows S2-1 energy vs time with a gate on energy in S2-2 being greater than 9MeV i.e. See previous elog also posted today for explanation.

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.

Jessica Tomlinson wrote:

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.

? 

As far as I am aware it has never been necessary to explicitly zero the 'raw' (or packed) data arrays containing the

ADC/TDC data and active channels in each event. Usually it is only necessary to zero those elements of the 'unpacked'

arrays which contain event data.

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.

tuda2 (by TUDA chamber, SEBT1) was powered off on arrival
- this may have been due to a previous power outage between
March 18-April 4. Rebooted OK.

MIDAS DAQ operational

MIDAS DAQ reads out CAEN V560 Scaler #1 channels #0-7 (see
file VMEDataSources below) on a per event basis.

Data directory tuda2:/data2/data/S1287

S1287 requires 64+64+32+16=176 channels of ADCs/TDCs
i.e. 6x Silena 9418/6V ADCs and 2x CAEN V1190A TDCs. 
Currently configured for 11x ADCs, 3x TDCs and 2x Scalers. 

Note - VME crate #2 (top) displays a yellow 'overheat'
warning LED. This is probably bogus - the air and PSU
temperatures reported by the front panel look OK.

MIDAS DAQ works for mode 'MIDAS Data Acquisition' and
'TUDA'. For the latter, all scalers and the EPICS variables
(defined by tuda:/MIDAS/TUDA/tcl/EpicsDefn.tcl - see below)
are readout every 20s.

Work permit (2011-4-11-3) was requested to vent SEBT1 upstream of TUDA chamber
and HERACLES to permit line-of-sight for alignment of TUDA chamber. Note that
Facility Coordinators are Lothar Buchmann/Pat Walden/Sky Sjue and Gordon Ball/Randy
for TUDA and HERACLES respectively. 

Wipe test was performed by Tom Davinson (PPE: respirator and gloves).
Samples checked by Fiona Holness RPG - check OK.

TUDA was successfully re-installed on SEBT1 by LB, TD, AML and PM.
Alignment checked by pillar mounted telescope downstream of HERACLES
and target ball between SEBT1 bending magnet and diagnostic section. 
With minor adjustments of upper stage table the upstream and downstream
targets were within 15 thou L-R/U-D. Upper stage table and feet locked.

14.00 Cryo pumped by TUDA2:BP5 to <100mTorr
      TUDA2.RVC5 closed and cryo compressor switched on
      See attachment 1 for EPICS log

Note: MiniSys Eye-IMG ion gauge installed (EPICS readout only)

Re-entrant flange assembly installed - currently the 'window' NW25
fitting is open.

Centre target ladder linear translator re-installed. Note the
downstream linear translator needs to be moved to the upstream
position.

18.28 Time from 1 bar to 250mTorr ~12m (turbo ON)
      Time from 250mTorr to 5.0E-4Torr ~5m (cryo ON)

Note: Transients in TUDA:PNG5:RDVAC when cryo gate valve opened
      Observed pressure decreases to <1E-10Torr (PM tells
      me that for this gauge this effectively means 'off'
      cf. the usual TUDA ion gauge which reads high when 'off') 

      Time from 5.0E-4Torr to 5.0E-05Torr ~6m ('good' vacuum)

      Total pump down ~24m (empty chamber)
      See attachment 2 for EPICS log

07.32 Tuesday 12 April
      See attachment 3 for overnight EPICS log
      TUDA2:PNG5:RDVAC 7.2E-07Torr

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

2um x 8 mm Ni windows leaked tested on TUDA gas cell. With window placed on the outside of the cell, cell was evacuated and pressure monitored with time, i.e. 1atm differential air pressure. Comparison to leak rate with blank flange also do.

Tests were performed in order: Ni, 30 minuets pumping, Ni again, blank, Ni third time.

Plots are the same data, different scales.

attached

note. s2 position in fig. 1 is wrong, should be 360mm.

27/06/11 - final version of safety report added (produced just before the experiment began).

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. 
     

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)

    

11.15 See attachment 1 for overnight EPICS log of TUDA2.CG5
      Downstream flange *not* secured by four bolts
      Current pressure 0.97Torr - rate of increase ~0.2 Torr/5h

      This history is very similar to the previous test (with 
      the flange secured by four bolts)
      - see https://elog.triumf.ca/Tuda/S1287/10

      Conclude - leak-in rate not affected by (i) lack of bolts
      securing downstream flange, (ii) addition of cabling within
      TUDA chamber - provided that the TUDA chamber has previously
      been pumped to 'good' vacuum (< 1E-05Torr, say).

16.40 Modified preamp services cabling to avoid unterminated test -
      input to PD preamp which causes reflections to previous test -
      inputs to the S2 preamps.

+/-15V PSUs

      #1 +15V/0.25A -15V/0.1A (1x 16ch PD preamp + 1x MSL type W preamp - not installed)
      #2 +15V/1.5A -15V/0.55A (2x MSL type S2 + 1x 16ch PD preamp units)

16.51 Time to 250mTorr ~14m
      Time from 250mTorr to 4.75E-05Torr ~40m
      See attachment 2

17.50 FTS RS44 set point +5.5 deg C

18.48 TUDA2.PNG5 7.8E-06Torr

      FTS RS44 set point +21 deg C
      Cryo pump gate valve closed
      Turbo pump off
      Four bolts securing downstream flange removed
 
      Vent to c. 300mbar with *He*

      N.B. TUDA2.CG5 reads 770 Torr with 300mBar of He in TUDA chamber

      MKS Baratron (capacitance manometer - gas independent reading)
      attached to manual vent port of the Varian V550 turbo pump
      Pressure reading at 'good' vacuum 0.0 Torr - no offset

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

19.08 300        221.7
19.18 300        222.0      +19
19.28 300        222.1      +20
19.38 300        222.3      +20
19.48 300        222.4      +21
20.08 300        222.6      +21

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

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

09.31 300        222.9      +22
10.30 300        223.1      +22
11.29 300        223.2      +22
12.29 300        223.3      +22
13.26 300        223.3      +22
14.27 300        223.5      +22
15.27 300        223.6      +22
16.28 300        223.7      +22
17.28 300        223.8      +23
18.28 300        223.9      +23
19.27 300        223.9      +23
20.27 300        223.9      +22

RAL109 Shaping Amplifier Modules

                    RAL109     Nominal  Nominal  Minimum
                    Resistor   FSR      Gain     LLD
Detector  Channels  DIP        (MeV)    (keV/ch) (keV)

S2-1 p+n  0-47      3.3k       71.4     18.6     1300
S2-1 n+n  48-63     3.3k       71.4     18.6     1300
S2-2 p+n  64-111    1k         33.3      8.7      600       
S2-2 n+n  112-127   1k         33.3      8.7      600
W p+n     128-143   1k         33.3      8.7      600
W n+n     144-159   1k         33.3      8.7      600
PDs       160-175   10k        183      47.7     3400

All RAL109 LLDs set to ~10mV (minimum)

CAEN V560 Scalers

Channel

0       Triggers
1       Triggers accepted
2       1kHz clock
3       Ortec 439
4       Pulser
5
6
7

8       S2-1 OR ch 0-15
9       S2-1 OR ch 16-31
10      S2-1 OR ch 32-47
11      S2-1 OR ch 48-63
12      S2-2 OR ch 64-79
13      S2-2 OR ch 80-95
14      S2-2 OR ch 96-111
15      S2-2 OR ch 112-127

16      W OR ch 128-143
17      W OR ch 144-159
18      PD OR ch 160-175
19
20
21
22
23

24
25
26
27
28
29
30
31

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

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

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.

Alignments checks revealed that downstream end of TUDA was ~1mm off (can't remember which way).

Re-entrant flange (window end) found to be ~5mm too low and ~2mm to the left. Checked upstream end of chamber and was ok.

Removed bellows etc. and re-entrant flange, replaced with re-entrant flange bolts only figure tight. Tighten bolts from inside chamber whilst checking alignment, adjusting as appropriate.

Managed to get to ~0.5mm to the right and ~0.25mm too low.

This is acceptable so closed chamber and checked vacuum down to ~150mTorr.

> Alignments checks revealed that downstream end of
> TUDA was ~1mm off (can't remember which way).

Was the downstream flange bolted into position?

York W detector 2635-19

1037um

As you can see...

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.

 In attachment are the peak position in the photodiodes (with high gain setting) for the target thickness measurements.

I've analysed data from runs 4 to 12, which were the alpha irradiations of PD1 and PD3 through the foils.
Time, 'target', which PD is being irradiated.

21:02 Ch2A 1
21:30 Ch2B 1
21:49 Ch2C 1
22:09 Ch2D 1
22:30 AuC 1
23:16 2mm 1
23:35 Au         3
24:23 4mm 3

Data are being sorted with sort.f, with the new variables file which has offsets and gains. 
The offsets should be fine, but the gains are based on data taken with the PDs in their
low-gain 'run' configuration. For these data, to be able to resolve energy loss at the scale of 10's keV, 
we needed higher dispersion, so the gains were increased. Hence the gains in the variables file 
cannot be used. We do a new energy calibration here.


Peakfind has been used to find the centroids of all relevant peaks. 
Using 2mm hole data (no energy loss except for deadlayer) I find the calibration of PD1 to be 4.74379 keV/channel. 
Likewise, using 4mm hole data for PD3 I find PD3's energy calibration to be 4.78963 keV/channel.


Energy losses for the three alpha peaks (5155, 5485, 5805 keV) are then:

Foil ch2-A: 

1077.0 keV
1020.4 keV
972.9 keV


Foil ch2-B

1121.6 keV
1060.8 keV
1010.9 keV


Foil ch2-C

1059.6 keV
1005.1 keV
952.2 keV


Foil ch2-D

1162.3 keV
1101.2 keV
1072.6   keV


Foil thin ch2+flash gold

12.3 keV
8.5 keV
10.3 keV


Foil: Thick gold

50.7 keV
50.4 keV
52.4 keV

 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

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.

Plan for shift was to increase trigger thresholds on S2-1 and S2-2 to cut out the low energy "stuff" which is dominating our trigger rate, and preventing us from increasing the beam current. S2-1 thresholds were at 10mV and S2-2 at 25 and 30mV.

Increased all S2-2 thresholds to 30mV and took runs with S2-1  at 11, 15, 20 and 40mV. Trigger rates seem unaffected. Low energy peak in S2-1 spectra are unaffected, however the bump at chn. ~380 was shifted up as threshold increased.

Looking at energy-energy spectra from sorted data, see lots of events at very low energy (y axis), across all channels (x-axis).

Concluded that the low energy peak is real coincidence, so can't be removed by increasing trigger threshold (as it is in coincidence with stuff in S2-2), and the "bump" is singles, so is being cut out as thresholds are increased.

Not clear whether the low energy peak is reactions, or something else, but the result is we can't increase the thresholds to cut the rate and allow the beam current to increase.

Following discussions with Brian, the interpretation of this may not be correct.

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

At approximately 7pm, noted that trigger rate in S2-1 had dropped by factor of ~20. Detector had tripped off due to leakage current reaching 8uA - spotting this was delayed as camera (or web-browser) monitoring currents had frozen. Current trip point has been increased to 12uA, and the beam intensity lowered to try to preserve the detector through out the night.

At some point this may be increased again but that will have to await a discussion of how much the detector can take. Replacing it would take ~6hrs so ideally we'd like it to survive until the end of the experiment.

For the time being we need to monitor the leakage closely (and ensure the web cam image is updating) and if the trip point is approached, either lower the beam current or switch off the detector for a while to allow it to recover, or both.

still running at 3.98 MeV/u

19:08

S2-1 had tripped off due to leakge current going above 8uA

Camera watching leakages had also frozen so didn't realize until we checked downstairs

asked to lower beam intensity down to 55epA (was 120epA) @ run119

23:22

asked to set beam intensity to 100epA

upper limit of leakage set to 20uA

S2-1 leakage current ~9.93uA

Sorted Runs:

run120

run121 still running

Please note that these procedures are not perfect and other small operations not listed may need to be carried out. Some mistakes may still exist in these procedures which could introduce significant risk if not spotted and corrected during the process. These should only be carried out by people confident they understand the system and the purpose of each step, giving due consideration to each step to ensure it is appropriate and safe.

In other words, don't blame me if it all goes horribly wrong!

S1287 data files R1_*.gz to R100_*.gz transferred from directory
tuda2:/data2/data/S1287 to directory tuda3:/data3/data/S1287

This releases c.18Gb of space in the tuda2:/data2 filesystem

1) PD run with gas (250Torr) - done

2) Pump down to 50 Torr - done

3) PD run - done

4) Take data (PD out) at 50Torr ~2 hrs. ~110epA - done

5) Pump out - done

6) PD run (no gas) - done

   a) remove 5mm collimator and run without gas, ~100epA (no PD) - done

7) Complete H2 venting process - done

8) Open up, sources in (window off) - done

9) Pump down - done

10) alpha data (some of the S2-1 inner strips look  very ill indeed , but all but one or two show clear triple-alpha peaks.  - done

11) pulser walkthrough - done

12) vent and open up - done

13) dismount detectors and re-entrant flange - done

14) pub!

Done - finished at 7.30pm, pitcher of ale methinks. 

Attached is a spreadsheet summarizing all the run information from the experiment.

Attached. Book 13 is split into 4 sections as otherwise the file is too big for the elog to accept.

This is reachable and change-able via outside Internet