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.

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();

    }

}

*********

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

Photos

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.

- 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