The 2D energy spectrum of Ca41 (36 runs). The expected alpha energies are 4.8 MeV (alpha_0) and 2.7 MeV (alpha_1).

Excel sheet for presence at CERN during 41Ca run. Please update if required. 

https://docs.google.com/spreadsheets/d/19OzH7bpnHb-YeOskNBGlrhEkPZmDsPDw9y0tleU0Soo/edit?gid=0#gid=0

Photos setup

Excel Sheet 

Uncalibrated amplitude spectra of Boron (run221188) after the settings were changed, the pulser was removed, and the threshold in the UserInput has been lowered. Both alphas can be seen in the front and back strips. The ratios between the alphas are similar for front (0.066) and back (0.063) strips.

1- Uncalibrated amplitude spectra of strip 2.

2- 1- Uncalibrated amplitude spectra of strip 19.

Plots of Boron #1 run (221141) from the Ca41 campaign with the right voltage applied (11.07.2025).

1- Uncalibrated amplitude spectra of strip 1 (dedicated).

2- Uncalibrated 2d energy plot of Boron dedicated data.

3- Uncalibrated amplitude spectra of strip 22 (dedicated). The alpha-0 on the back strips has lower counts.

Plots of Lithium #3 run (221136) from the Ca41 campaign with the right voltage applied (11.07.2025).

1- Uncalibrated amplitude spectra of strip 1 (dedicated).

2- Uncalibrated amplitude spectra of strip 1 (parasitic).

3- Uncalibrated 2d energy plot of Lithium dedicated data.

List of the detectors and the connections.

This Excel sheet has the detector bias-leakage current data and plot for both detectors.

Detector 2 has lower leakage current and a flatter plateau region.

I'm attaching a report for the experimental setup so far.

There is a main problem which haven't been solved yet and I don't know if that can cause problem in the future analysis.

Channels #23, #24, #31 and #32 are not working well. The signal os these channels look attenuated from the pulser, make impossible to see then in the Boron run.

As these channels are in the back side of the detector, it could be possible to run like? Unless we have more ideas about to solve the problem.

The front channels work well all of them, and the rest of the back channels work well as well.

I attach the current for the +15 and -15 volt applied to the PreAmp (low voltage) and the leakage current from the detector is 0.1 uA.

Manual - see attachment 1


Internal configuration

Voltage full scale - 400V/10uA

JP1/1-4 fitted
JP4 fitted *see note below
DVM card JP1 AB
HV jumpers AB

Current readout resolution - 10nA

DVM card JP2 LM
JP5/1-5 GH


Polarity - channels 1-4 negative

Note with channel 1 voltage set to -180V the output voltage measured by DMM is -40V.
The output impedance of the Silena 7710 outputs may be comparable to the input impedance of the DMM (DMM typically c. 20-40M) so the measured voltage will be a *lower* 
limit.

With JP4 removed (per manual instructions for voltage full scale 400V/10uA) the front panel reads -20V with an output voltage measured by DMM of -40V.
Again, the measured voltage will be a lower limit.

By observation of the behaviour of the electronic noise of p+n junction and n+n Ohmic strips as a function of bias for MSL type W1 DSSSD 3353-4 (75um) the voltage 
applied to the DSSSD is > depletion.
MSL QA tests report depletion voltage 28V and test/operating voltage 28+10V = 38V.

B looks as we are used to , Li tritons are now stopped in the detector and should appear around 2.8 MeV. 

Attached is the B10 and LiF data with Fast Fourier Transform and varying time constants.

The rootfiles countsB.root and countsLi.root contain histograms of count spectra that would be expected at n_TOF for a 10B and a 6Li target, respectively. The units in y are arbitrary. This can be used to check, if we can reproduce the expected trend with our Li and B measurements. So the histograms called "counts" can be directly compared to the histograms called "energy" in Sili_deed.c (they should have the same binning). You need to scale the histogram to get a decent overlap. You can use this also to estimate the neutron energy calibration - the thermal bump at low energy will give you a good idea of the flight path length. Structure at high energy will give you a better idea on the offset.

The files 6Li_endf.root and 10B_endf.root are the original cross section files, and countrate_calc.C is the file used to produce the count spectra.

The 2x sets of 34-way IDC to 37-way D connctor ribbon cables used at GSI for the two-alpha decay measurement have been located - see attachments 1-4.

They have been packed for shipment to CERN and delivered to stores for shipment. Awaiting quotation and P&M PO.

Neutron beam profile - film exposure overnight 12/13.9.24

We borrowed from n_TOF:

1x O-ring for circular side-flanges on the chamber (the borrowed part has a small green marker cross on it)

10x LIMO-to-BNC connectors (BNC female) from electronics lab outside EAR1

10 new Adapters for lemo to bnc on my desk