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

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.

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.

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!

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

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

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

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.

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.

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.

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

 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

As you can see...

 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.

 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 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.

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.