I want to update about the DSSSD analysis and the processing routine. First, I attach a few screenshots of how the average signals work. Still, it can be improved looking at the average signal close to the gamma flash or optimizing the PSA parameters.

On the other hand, the data processing is already working. I attacha document where I explain the steps that must be follow and changes needed to make it work.

1. LiF 2 strip comparison. This includes 12 runs.

2. LiF 3 strip comparison. This includes 4 runs.

3. K40 strip comparison. This shows 213 runs which have been grouped into 3 equally.

This is the energy deposited vs neutron energy plot of all ~220 runs of K40 and a few resonances can be seen.

October 22th. It's planned to remove the dummy sample on beam. We are planning to measured 4 references samples during the next two days.

- 6LiF #2. The 6LiF is deposited in the backing side. The measurement will be performed by using Al filter, Co - Mo- W and no filters.

- 6LiF #3. The 6LiF is deposited in the backing side. The measurement will be performed by using Al filter, Co - Mo- W and no filters.

-10B #3. The 10B is deposited in the frame side. The measurment will be performed without filters.

-10B #2. The 10B is deposited in the backing side. The measurment will be performed without filters.

For the moment 6 reference samples have been measured.

- 2 x 6LiF. The 6LiF is deposited in the backing side for both samples, #2 and #3. (Backing means the side from where the mylar has been glued)

- 4 x 10B. For the samples #1 and #2 the 10B is deposited in the frame facing the detector, and the samples #3 and #4 the 10B is deposited in the backing side.

During the last days, the two 6LiF samples will be measured, and the samples #2 and #3 samples with 10B.

During the intervention on Sunday there were some problems related to the detectors and the Dummy sample.

When we opened the chamber we realised that the detectors were not in place. It happened at the beggining of the experimental campaign while we were changing one of the references samples. As far as Emmanuel and I remenbered, the detectors were well fixed in the support, and we guess that the detectors moved as soon as we tried to open the chamber.

On the other hand, the dummy sample broke during the intervention. I attach a photo of the dummy sample.

About the 40K sample, it is in the vacuum box in good conditions.

This is the Excel sheet where the proton numbers and the runs are kept track of.

- run with LiF for a few hours with filters in the beam -- > this will help with the neutron energy calibration later

- run again LiF and 10B (not all samples, 2  LiF and 1 B are enough)

- run with the dummy sample

19th, 20th: LiF and B runs + runs with filter

21st dummy until 24th

Plot shows deposited energy (very rough calibration) vs Neutron energy (also very rough calibration). We expect the biggest resonances in the 40K(n,alpha) reaction at ~1 keV and 5 keV. There is an accumulation of counts at those neutron energies and around the expected Alpha energy (~3.5 MeV and ~1.8 MeV). 

In the proposal we expected in total ~2000 counts for those resonances for 4.5E18 protons. The plot shows 1/200 of the total statistics, so what we see is consistent with out estimation.

Photos

Two different runs of B2 and the DEED-EDET amplitudes.

1. The DEED amplitudes of Li2 run when the sample was not rotated.

2.  The DEED amplitudes of Li2 run when the sample was rotated. There are two clear peaks which indicate triton and alpha.

3. The EDET amplitudes of Li2 run when the sample was not rotated.

4. The EDET amplitudes of Li2 run when the sample was rotated.

root -l run219167.root

TH1F *h=new TH1F("h","h",5000,0,5000)

EDET->Draw("amp>>h","detn==7")

--> plots amplitude in the histogram specified for detector number 7

Strips 1-16 dE.

Strip 8 is not working. Strip 16 is drowing the 10B peak in noise.  All others  look ok. The low energy peak around channel 300 in visible in some strips may be the Li recoil. The main peak around channel 800 is 10B(n,alpha_1) at around 1.3 MeV. The alpha_0 channel should be at around 1.8 MeV. There seem to be two small peaks above the alpha_1 peak. not sure why.

Plotted using:

void plotfile(){

    TFile *f=new TFile("run219173_B_ded.root","read");

    Char_t s[256];

    TH1D **hamps;

    hamps=new TH1D*[17];

    //creating histograms for each strip

    for(int u=0;u<=16;u++){

        sprintf(s, "hamp_%d",u);

        hamps[u]=(TH1D*)f->Get(s);

    }

    TCanvas *c=new TCanvas();

    c->Divide(4,4);

    for(int u=1;u<=16;u++){

        c->cd(u);

        c->SetLogy();

        hamps[u]->GetXaxis()->SetRangeUser(0,2000);

        hamps[u]->GetYaxis()->SetRangeUser(0,50);

        hamps[u]->DrawCopy();

    }

}

*********

In the scheenshot attached, the LiF sample is the same but the number of signals are different and the amplitude. The LiF is the #2.

Therefore, according to the Emmanuel's plots, we were putting the LiF sample away from the detectors.

The runNumber 219135 corresponds to the LiF sample forward to the detector, and the runNumber 219167 corresponds to the LiF sample away from the detector.

edit: added screenshot of strip 5 amplitude spectrum from run 219167 where triton and alpha peaks are well separated.

Spectra after adjustments of the MWD and UserInput:

10B - Sample 1, 10B - Sample 2, LiF - Sample 2 and LIF - Sample 3.

We haven't seen the triton peak in any of the LIF - just noise and alpha.

The 10B alpha is also seen.

Strip 13 ampltiude spectra for the LiF and B samples. Also a picture of a simulation of what would be expected in a 20 um detector in terms of energy deposition for several reactions (assuming a thin sample).

- for B-10 n,alpha, the dominant reaction is n,alpha_1, so just seeing one peak makes sense

- for LiF we would expect 2 peaks, one around 1 MeV and one around 1.8. In the data it looks more like 1 peak while the lower energy "peak" is likely noise. My guess is that the sample is quie thick, which leads to a lower energy alphas, and a lower energy triton. As a consequence, the two peaks merge.

Conclusion:

- check the other LiF samples to see if we have any thinner samples

- try and rotate LI sample to confirm that the direction we are using now is the correct one.

Wiith the adjustments:

voltage and leakage current in dE are 7 V and 0.03 µA,  respectvely. (W1-20, 3186-9, 20 um)

voltage and leakage current in E are 47 V and 0.04 µA,  respectvely. (W1-150 3458-4, 144 um)

A logbook is attached to record what happened in the first weekend of the campaign, so as to keep track of the changes we made, before the 40K sample gets in. It will be updated tomorrow 15th Sept., 2024.

Things to organise for the future:

- plastic detecor mounts to electrically isolate detectors

- storage boxes

Screenshots of pulser signal  in DEED - 1-4 and EDET 1-4

Pulser settings:

- positive

- 0.5 V

- 20 Hz

A how to from last year, still relevant for this measurement (only the vacuum valve may have moved depending on the pump.

B10 and LiF samples have arrived at CERN.

There are 4 LiF sample, 4 Boron sample and one blank sample. All samples are attached to a square and are in good condition.

- new Kapton windows for chamber (underway, waiting for workshop)

- LiF and B samples from Daresbury: under production, will be shipped directly to CERN

- shorter flat cable: will try again to make a proper flat cable that is shorter. check with Tom

This is a new elog tab dedicated to the 40K(n,p) and (n,alpha) experiment. Things to be prepared before the run (start of run TBD):

- new almunised Kapton windows for chamber (Peter has ordered material)

- Lemo - BNC converters (most availanble, 10 new ones in my office)

- 10B and LiF reference samples: being prepared by P. Morrall in Daresbury

- 40K samples: one 40K (16% enriched) prepared by PSI, one highly enriched 40K sample will be produced by implantation at iThemba labs. Implantation will commence around May for about 6 weeks.