AIDA GELINA BRIKEN nToF CRIB ISOLDE CIRCE nTOFCapture DESPEC DTAS EDI_PSA 179Ta CARME StellarModelling DCF K40
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ID Date Author Subject
  9   Thu Mar 2 13:00:06 2017 DK26Al ground state beam
Attachment 1 shows a comparison of the zero-degree telescope from the decay measurement with the 26gAl beam produced today (left side) and a GEANT4 simulation by Shimizu kun 
some months ago.  

I discovered two reasons that July 2016's beta spectrum did not match the simuation:
    1) The threshold was too high, so we should try to decrease it during another test soon
    2) There was a strange bug in the code that also affected the spectral shape.

Now the comparison of the beta spectrum between our measurement today and the GEANT4 simulation is excellent.  (There are some differences in the setup, so that may account for 
some of the small variations).

My calculation of the isomeric purity output the following results:

root [0] .x macros/purity.C 
Run number: 46
Solid angle: 0.0386799
Betas: 3.42938e+07
Purity (PPACa): 0.862612
Purity (PPACb): 0.906841
Isomeric purity (PPACa): 0.281095
Isomeric purity (PPACb): 0.276141

(This differs from the online logbook, as I mistakenly used the PSD solid angle instead of the first SSD layer.)

Keep in mind that the lowest-energy tail of the beta-spectrum in the experimental data are absent, and so the actual isomeric purity is slightly higher than above (but it seems 
negligible if I take the 25 keV/bin setting, assumed from 0~200 keV misses around 500 counts per bin)

Still, the beam seems to be around 70% ground state.  However, keep in mind that our isomeric purity from the test run was somewhere around 42% so the difference is only 10% 
which may be small, and so we should make a stronger effort to make the higher purity isomeric beam, maybe tomorrow.
Attachment 1: beta-spectrum-exp-v-sim.png
beta-spectrum-exp-v-sim.png
  8   Wed Feb 22 14:06:47 2017 HSNaI preparation

Today we took datas of NaI detectors one by one for calibration. The gamma ray source was put on the NaI surfaces so that peaks could clealy appear where we expected.

We fitted them with gaussian and exponential, and integrate the peaks to calculate yields. The results were pretty good. 

However, at the test experiment last year, some NaI gains gradually shifted lower and peaks moved left during the beam time. So we need to let threshold level of CFD down NaI2 and NaI3 and NaI5, or change the fast amp gain and use downscaler, otherwise the part of peaks may go down below the threshold.

Probably NaI works have almost finished before setting up geometry I hope.

Attachment 1: NaICalibration_Cs137.pdf
NaICalibration_Cs137.pdf
Attachment 2: NaICalibration.pdf
NaICalibration.pdf
  7   Wed Feb 22 05:31:42 2017 DKFacility Notes
Here I make a running log for CRIB general notes that may be useful for future experiments.

1) The camac initialization scripts stored on analys2 PC should also be made into experiment-by-experiment directories.  Particularly settings for the ADC and other things are 
not always the same in experiments, and it would be convenient to have a record of that.  If it is modified and then entered into the j1init script, then it would be a relatively 
seamless process for users while still maintaining the record.  In the case that the absolute file path is really necessary for some reason, then symbolic links could be used to 
do it instead of changing the place of the script each time.
  6   Tue Feb 21 16:28:19 2017 HSNaI adjustment

Yesterday we improved NaI spectra by checking them one by one with lead blocks stacked as a housing. Though the threshold levels of CFDs were few mV or less than 20mV and a bias of NaI7 might be high (~1500V), the shapes of spectra looked OK. Now 511keV peaks are around 1500ch in every sprctra.

## To-do list for NaI detectors ##

1.Check efficiency and calibrate NaI by using Na22 source and Cs137. Basically the interest of region is around 511keV and we need precise information up to 1MeV so that Na22 and Cs137 are enough to calibrate.a

2.Align NaIs on F3 chamber after the other F3 works done. I'm thinking of an arrangement of the NaIs array like, for instance, NaI7 should be put outside, and relatively good NaIs should be at center.

3.After setting them on a bucket, check efficiencies again. For testing positional dependenices, we should do it from several different positions.

4.Determine the threshold level of CFDs so as not to make DAQ busy. (It can be solved by using divider?)

 

  5   Tue Feb 21 12:46:24 2017 DKF2, beta tests of SSDs
Status of today's work to follow...

===F0===

    Leak rate of the gas cell was found to be < 1 Torr / 3 hours.  Cell was evacuated.

    With the present setup, probably none of the foils can be rotated in front of the target.
       Impact will be evaluated later.

===F2===

    F2 SSD was checked with alpha-2, and it's dynamic range was set to around ~210 MeV.

    F2 PPAC was checked with a mask using alpha-1.  No anomalies were found.

    F2 chamber was opened and the sources / mask were removed.

===F3===

    Kinematics calculations suggest we should use a total of seven 1.5 mm SSDs (2 at each telescope, plus the additional one for betas at zero degrees)

    F3 was vented and the masks were removed from PPACs.  Covers were installed.

    Clear Pulse preamps were checked:
      There are 6 good channels on the existing two
      A third preamp was marked as non-functional in 2016.10, but we found it is the test channels that do not function.

    We quickly checked five CNS 1.5 mm SSDs with a 90Sr/90Y source in air.  
      The findings were consistent with the 7Be THM experiment evaluation of detector quality.

    We noticed on of the PSD feedthroughs is absent inside the chamber.  It needs to be installed and checked.
     

===NaI===

    Unfavorable spectral features were removed from many detectors.

    Detectors are being tested one-by-one, as well as combinations of detectors and cabling, to search for the cause of problems.
  4   Mon Feb 20 10:01:06 2017 DKF0, PPAC, and DSSD signal checks
Today the following was performed:

===F0===

Chamber pumps were turned on (though the chamber was still under marginal vacuum from previous exp of ~10 mbar).

H2 gas was filled to check the windows at 551 Torr.  After >6 hours, leak rate is ~1 Torr (~4 Torr / day).

===F3 PPACs===

The F3 chamber pressure was below 5 x 10^-4 Pa, extremely good for F3.  Even with PPACs having gas, the baseline did not change.

Strange behavior was seen with the evacuation of the gas system and connecting the gas system to the PPACs.  There appeared to be pressure backflow frmm the pump.  This causes 
minor jitter in the current when bias was applied at first, and also strange temporal data.

After lunch, we found the input to the pump has a very severe leak.  Once it was replaced, the PPACs could be operated normal, including the expected spectra.  It could be 
possible the high discharge frequency and lower bias settings used, e.g., in 7Be THM exp in 2016.11 was partly due to this issue of contaminants in the gas.

Now the chamber pumps were turned off, in case we open the chamber tomorrow.

===F3 DSSDs===

Now all the cabling is connected in both E7 and J1.  Many more things are properly labeled.  

We had trouble to find all the signals generated via pulser in the DAQ.  PSD1 data showed up right away.  We could find PSD2 data after a change to the camac init script 
inputs.  The issue of PSD3 remains to be resolved (but at least there are no longer encoding errors, so perhaps it is a problem in ANAPAW.
  3   Sat Feb 18 11:10:49 2017 DKDSSD mapping
Today we set up and labelled the amplifiers and feedthroughs from E7 to J1.  Unrelated to that, when we arrived at 13:45 the F3 pressure was 1 x 10^-3 Pa, and at 19:45 
departure it had dropped to 9 x 10^-4 Pa.

Patches are as follows, following the standard CRIB convention for this type of experiment.

B: PSD1X
C: PSD1Y
D: PSD2X 
E: PSD2Y
F: PSD3X
G: PSD3Y
H: PSD1T
I: PSD2T
J: PSD3T

Considering the differences with the previous experiment (7Be THM 2016.11), a majority of cabling was switched or is newly done.

12 8-ch amps, 3 16-ch fast-amps, and 12 4-ch CFDs were set up, half of the amps inverting and half non-inverting, all using the high-gain chips.  The inverting amps have the 
preamp signal daisy-chained to the fast-amp which are connected to CFDs for the timing.  All amps, fast-amps, and CFD outputs are connected to the E7-side cable patch.

The two 19" racks behind the F3 chamber were swapped, since the capacity of each rack did not match the new asymmetric preamp setup.  All feedthrough cables were removed (as 
most needed to be changed anyway and then reassigned to a convenient location for a logical structure.  

deltaE-E telescope numbering goes from #1 to #3, from left to right, as seen from the beam's perspective.  Thus #1 & #2 are processed on the beam left side, and #3 is processed 
on the beam right side.

The crate order (looking upstream now, beginning from the left) then has 3X & 3T on top, and 3Y beneath.  On the right-hand rack, 1X & 1T on top, 2X and 2T in the middle, and 
1Y & 2Y on the bottom.

The racks were also moved slightly apart, with the main considerations that enough space be available to (somewhat easily) pass F3 on the beam left side, but also that we can 
easily access the rear center of the F3 chamber (which was less relevant in the previous experiment).

Most of the preamps are not connected to anything, and half of the ADC inputs to the CAMAC crate in J1 are also missing inputs (but we found 6 appropriate cables).  Most other 
things are completed, with exceptions including the HV wiring, J1 triggering, and anything related to the DAQ and/or calibration.  The gains and thresholds still need to be 
checked as do the channels.

Nothing was done for the thick SSD signal processing yet.
  2   Fri Feb 17 11:33:45 2017 DKMeeting Memo and Prep Status
In today's meeting, the following points were discussed / revised / added considering the Inventory and Status eLog.

Simultaneously I discuss today's work where applicable.

=== F0 ===

We will probably not use the carbon stripper foil.  Although it would be interesting to confirm (or finally refute) the Leon charge-state distribution model for work at CRIB, 
the stripper foil lifetime probably cannot be more than several days of beam.  E.g. in 30S experiment, a 2.5 um Be foil was broken by the primary beam after only a couple of 
days (28Si at 205 MeV and 70 pnA).  We do not have very many foil mounting positions to put in ~5 stripper foils to F0.  Moreover, we got ~10^5 pps of RIB at F3 in the test 
experiment, but the ion source operation was not good, and we are expecting >=5 times more primary beam intensity in the main experiment.  Thus if the stripper foil really 
works well (factor 5--10 higher 26Al13+ intensity) we would have over 10^6 pps which the PPACs (and probably DAQ) cannot handle.  Once the stripper foil breaks, we need to 
retune Brho which means our RIB production optimization is lost and needs to be partly redone (several hours of work, perhaps).  I will check some stripper-foil lifetime papers 
this weekend, but empirically for CRIB energies I think we know the answer.

=== F1 ===

It was unanimously agreed not to open F1.

=== F2 ===

The BRILLANT+C project requested some measurements for the machine time in April.  F2 was opened in the afternoon and the measurements were made.  We will still plan to check 
the F2 PPAC and F2 SSD next week.

=== F3 SSDs ===

Now all the circuit boards for the Edinburgh SSDs are made, and after some further modification, it was confirmed that there is not cross-talk between X and Y sides.

Although we did not check any local SSDs or the list, CRIB local members were of the opinion that there are a sufficient number of SSDs for three telescopes.

We replaced the beam-left pre-amplifier Faraday cage with a larger one.  Yamaguchi san found the spare PA chips.  All channels were tested, and we have 96/96 working channels.  
One PA box was found to have ~2.5x higher gain (so amp setting shall be lower for that one).  The PAs were roughly installed into the Faraday cage as well.

In addition to the 207Bi beta source of RIBF, CNS has the following sources:
60Co (x2), 90Sr.  The RIPS 22Na is also a beta source.

We decided not to measure 26Al beam energy at F3.  One point that was overlooked in the previous eLog is the time required to calibrate an F3 SSD for heavy ions.  If we decide 
it is really necessary to make such a measurement, an appropriate circuit could be constructed during the beam time in under 1 hour.

Splitting the PA signal to two amplifiers for the forward-angle thick SSDs seems like the best option for measuring both protons and positrons, so we will try that.  We will 
use a common TFA, however (so the PA signal will be split 3 ways rather than 2 ways).

Because the zero-degree telescope is very close to the chamber wall and will have 4 layers (rather than 3 from the machine test), we decided to install the small pipe (~10 cm 
length) between the chamber and the flange.  This will give a little more space for the detectors and cabling.  We did it after the meeting.

=== F3 NaI ===

The spectra in the logbook were showing the situation before Pb shielding was added to block radiation originating from the beam line pipe.  We should print the new spectra.

Since the CAENNET is working, we don't need to use the local keyboard and monitor.  Instead we can connect via a laptop. This should help to ease congestion around the F3 
chamber during preparation, since much of the NaI work can be done anywhere in E7 or J1.

=== F3 Targets ===

The five targets planned for use are:
    30+50=80 um CH2
    11 mg/cm^2 Carbon
    Blank target
    Al block
    Plastic block

The new target mount, Al block, and plastic block are expected to arrive from the company early next week.  The Al block used in the test experiment had many holes in it 
(though it was covered with Al foil and tape to ensure at least the RIB is stopped).  This may explain minor discrepancies between the data and the GEANT4 simulation.  Plastic 
will be used in addition to Al because it has less attenuation for gamma-rays, which may also help to understand the 511 keV gamma-ray data during the half-life (isomeric 
purity) measurement.

=== F3 PPACs ===

Today, alpha-4 source was placed in F3, both PPACs were moved to the "in" positions, covers were removed, and masks applied.  We evacuated the chamber.  Within ~1 hour, already 
the vacuum level is 1 x 10^-2 Pa.

=== Other ===

On 2.27, some workers will come to install a new hydrogen gas level detector near F0.  We should try to avoid doing alignment on this day, at least when the workers are 
present, since they could disturb the laser position by accident (although, it is the ideal day for alignment based on the beam time schedule...!)
  1   Thu Feb 16 10:05:04 2017 DKStatus and Inventory
Today I surveyed the lab and associated rooms to determine open questions and the required preparation work.

=== F0 ===

I want to try using a stripper foil again.  During the beam test, we determined with a blank target that the small aperture itself limits the transmission.  The diameter was 1 
cm (should be verified).  We can try with a larger foil this time.  

I found my old carbon foils in the clean room nominally of 220 ug/cm^2, 330 ug/cm^2, and 560 ug/cm^2.  The original size is 24 x 68 mm^2 (though some have been previously cut 
and used).  We can have a target more than twice the diameter and see if it helps this time.  220 ug/cm^2 is sufficient for nearly-complete charge-state equilibrium, and would 
induce about 2.3 MeV of energy loss for the 26Al beam (using the beam energy obtained during the test).  

To do: 
    0) F0 gas cell pressure test (before new foils installed)
    1) Check the target frame and mounting situation
    2) Decide what other thin foil (Al or Havar) might be useful
    3) Mounting, alignment
    4) Fill LN2, set up cameras, beam viewer ...
    

=== F1 ===

Probably nothing to do.  Situation normal.

=== F2 ===

Situation looks okay.  We could test the SSD (triple alpha source) and PPAC with a mask.  

To do:
    1) Dynamic range needs to be adjusted (different from 7Be THM experiment in 2016.11)

=== F3 SSDs ===

4 Edinburgh W1-1500 SSDs were brought safely from the UK.  Yang and I tested additional PreAmps today, and it seems we have 93 out of 96 channels available for the DSSDs so we 
can use three deltaE-E telescopes.

To do:
    0) Circuit boards for Edinburgh SSDs (commonly wire 16 channels to 1) ... several are already made I believe
    1) Check status of local SSDs, especially 75 um DSSDs and determine which to test / use in exp.
    2) Remove beam left PA Faraday cage and replace with larger one (NB: need to find vertical supports)
        a) The beam right PA box only has 2 feedthroughs (2 used per DSSD) and the left one has 4 feedthrough
        b) Present PA boxes only hold 6 PAs each, but the larger box can hold 8.
    3) Check the gain chips on all the amplifiers.  They may need to be changed compared to the 7Be THM exp in 2016.11
    4) Wire additional circuits for 3rd DSSD (circuits for #1 and #2 are existing).  All modules are existing
    5) Decide if we measure the 26Al beam energy directly at F3 with the blank target
        a) If so, we need another smaller circuit for low-gain
    6) Check all SSDs.  We can save time using 207Bi beta source in air for the initial check of 1.5 mm SSDs
        a) We will already need the source for beta calibration, and it is existing at RIBF
    7) Determine method to employ for 2 gain settings of forward-angle SSDs
        a) We adjust the coarse gain knob on Ortec 572 Amplifier
        b) We use two separate circuits and move the signal cable from one to the other
        c) We use two separate circuits and split the PA output
    8) Choose F3 Si telescope floor plate (several are existing in the red toolbox)
    9) Determine if the Si telescopes can be moved below the NaI bucket position, for alignment and installation safety
        a) Typical setting of the F3 downstream floor is ~170 mm.  But labels are contradictory ('180 max' vs '190 max')
        b) If this won't work, we need to consider how to do alignment.  Thinner floor plate of 8) preferred for this reason.
   10) Noise reduction, threshold and FastAmp settings, alpha calibration, beta calibration, DSSD masks, etc ...
   11) Camera to monitor biases

=== F3 NaI ===
Already some tests were performed before I arrived.  I also moved the 'bucket' from under the E7 stairs to near F3.

    1) Understand the strange spectra obtained so far
    2) Find optimal offline setup (present setup may be cramped if teams for SSD and NaI work in E7 simultaneously)
    4) Efficiency check in offline geometry
    5) Energy calibration, noise reduction
    6) Installation into chamber (last day), new efficiency check
        a) Check if the number of detected gamma-rays is changed by placing a ~1 cm Al block near the 22Na source
        b) This could confirm our results from the test experiment

=== F3 targets ===
The new target mount was ordered.  Imai san loaned me the ~10 mg/cm^2 carbon targets.

    1) Install all targets (CH2, C, thick stopper, blank
    2) Check controller works, etc
    3) Alignment

=== F3 PPACs ===
These are existing from the 7Be THM experiment and already installed in the chamber.

    0) Pump down F0 overnight to achieve good vacuum.  Make sure vacuum acceptable when PPACs filled with gas.
    1) Check with masks
    2) Alignment
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