Models Vs Resonance amp spectra 

Isoflex certificates for enriched silicon samples

Au and Si29 runs normalised by proton number show consistency (dedicated pulses, example detector 4). Plots for tof spectra zooming on one resonance and histogram of counts in this resonance divided by protons with statistical errors.

Plots were produced with the macros attached.

Sample information Excel sheet attached below.

Images 1-6: Si-29 sample

Images 6-10: Si-28 sample

Image 11: screenshot from Excel sheet for Si-29

Image 12: screenshot from Excel sheet for Si-28

Image 13: screenshot from Excel sheet for Dummy

Both samples were only able to be weighed inside the capsule as they were very crumbly and unable to be weighed alone (see images). The capsule was weighed before the sample was put in it and thus the mass of Si can be found by subtracting the capsule mass from the measured mass.

Average mass Si-29: 0.8568g pm 0.0002

Average mass Si-28: 0.9551 pm 0.0002

Average mass Dummy: 0.0765 pm 0.0001

https://docs.google.com/spreadsheets/d/18lk27N6Pb2iT_xtDA-1T1c9vVubXTJ0OsaDjOxErP0I/edit?usp=sharing

Campaign started yesterday. C6D6s placed at 9 cm distance, angle 125 degrees w.r.t beamline.

Measured calibration sources: Cs137, Y88, AmBe, CmC. Measuring Si-nat over the weekend.

Detector          Voltage

Updated plots with new WFs. Rebinned by 10.

Plots made with new weighting functions. All rebinned by 10.

Attatchments 1-4: Detector 1.

Attatchments 5-8: Detector 2.

Attatchments 9-12: Detector 3.

Updated plots for Zn and Au

Plots for Zn and Au with Empty subtracted, and compared to weighted spectra.

Note: Au are logged x and y, Zn is only logged x.

Here are all the files needed for calculation of the yield. There is some information that still needs to be added to the energyandyield.c file, for example the atomic mass of your target in amu, the neutron separation energy for the compound nucleus in MeV (this is needed due to using the Weighting technique). Also, you need to add some lines  to read the tof histogram, which will then be converted in a neutron energy hisogram and then divided by the flux.

For the conversion to neutron energy we assume an approximate flight path for now. We will determine this more accurately once we have the yields and fit resonances. Emma will need to use a different flux than Annie, because we have a different spallation target. Emma's flux is preliminary, so we also should look at the SILI detectors at some point.

There are some more instances where names for rootfiles and ascii files need to be added. In the first instance, please try and add the missing information and try running the code. I haven't tested it so there may be still problem.  To run it you will need to download the 3 rootfiles into the same folder (or move somewhere else and adjust the path name in the .c file.

PLEASE set variable THRESHSCALER to 1 for now. We dont know yet what it is :-)

Below are graphs for the comparison between background corrected and uncorrected spectra (weighted) for Si-30, Au20, Au22 and Sinatgood.

This is just for C6D6 detector 1 but all detectors are consisitent. All histograms have been rebinned by 100 for clarity. 

Below are graphs for each sample (weighted) showing the comparison between ambient spectra, empty/dummy holder and sample spectra. 

All four detectors are shown for each sample (Si-30, Au20, Au22, Sinatgood). 

All histograms have been rebinned by 50. 

Below are histograms for the weighted spectra (with deadtime correction) with and without ambient for C6D6 detector 1.

For each sample the histogram with ambient is first and then without ambient (please ignore histogram titles). 

The Dummy, Empty and C-nat have been rebined by combining 100 to 1.

The Au20, Au22, Si-30 and Sinatgood have been rebined by combining 10 to 1.

Si-30 WF used for: Si-30, Dummy, Empty, C-nat

Au20 WF used for: Au20

Au22 WF used for: Au22

Sinatgood WF used for: Sinatgood

Si-30:

Histograms for deadtime correction for all 4 C6D6 detectors for parasitic beam.

Histograms for weighted and deadtime corrected parasitic spectra. 

Si-30:

Histograms for dead time corrections for all 4 C6D6 detectors.

Histograms for weighted and deadtime corrected dedicated spectra. 

Weighting function for Si-30, Au22, Au20 and Sinatgood applied for parasitic and dedicated beams. 

Here are the Processing files for EAR1 and EAR2 with calibrations.

Below are the histograms of parasitic vs dedicated runs for EAR1. Also included are histograms with ambient background removed which closes the gap between parasitic and dedicated histograms. This was preformed by scaling the ambient by counts by a multiplication of (dedicated or parasitic) bunch number/ambient bunch number. There are no legends but the dedicated counts are in black and parasitic counts in red. Only included are C6D6 1 detectors but the other three detectors were equivelant. 

Attatched are the overlayed compton edges for the calibrated experimental and the GEANT4 simulations. Note p1 and p2 denotes the lower and higher energy compton edges for Yttrium. 

The experimental and simulated histograms are shifted in quite a few of these plots suggesting the calibration was not fully successful. The compton edge for AmBe was difficult to locate and may have contributed to the poor calibration. 

Calibration parameters for each STED detector: With function f=p0+p1*x+p2*x*x

A quadratic function was fitted to the reference point channel (from experimental histogram) and reference point energy (from simulation histogram). The reference point 'r' was r=mean+(FWHM/2) for a gaussian fitted to each compton edge. A quadratic function was used as it fitted the higher energy AmBe reference point better than a linear function. This is highlighted by the comparisson of "STED 2 Calibration" and "STED 2 Example Linear Fit Calibration" plots below. The p0 error is quite large and p2 error very large (larger than the parameter value in STED1) - however the parameters are highly correlated which may have inflated the error. 

CmC histograms were not used as the compton edge could not be located. 

For reference the STED 1 correlation matrix:

All plots in the ratios all look pretty contstant. Zn1 for all detectors seems to have some strange spike in the integral, and a dip in the SILI measurements (and therefore in the SILI/PKUP ratio). 

Det1 & Det4 dont look great for the Integral/Proton plots, im planning to make these plots with the PKUP protons and SILI and then comapre all of those errors and ratios that come from those, so we'll see what that comparison brings. 

Nothing has been seperated by dedicated or paracitic beam yet, so those comparisons need to be made too. 

The EAR2 ratios of BCT/PKUP, BCT/SILI and PKUP/SILI plotted for each run for samples Si, Sinat, Au20, Au22 and Dummy. 

Also included is the normalised counts (counts/BCT) with 7 detectors on one plot (STED8 was ommited).  'counts' for Si was integreated over the Si resonance, for Au it was integrated over the largest resonance. For Dummy and Sinat the counts were integrated over a large range of 1e+4 to 1e+6ns. The Sinat resonance was too small for adequate statistics to only integrate over the resonance hence why a large range was used. The C6D6 normalised counts were not plotted as there seems to be issues with this detector in EAR2. 

There seems to be issues with the EAR2 C6D6 T histograms. For Au the earlier run seems to be shifted for detector 2 compared to the rest. 

For Si plotted is 3 different runs 216123, 216128 and 216135 for both detectors. The histogram is messy but highlights that there is a problem. The single Si resonace should be around 20 000ns and this is only the case for run216128. 

Apologies for no legend on plots. 

Au22
det1 run216158 black
det1 run216109 red
det2 run216158 green
det2 run216109 blue

Au22
det1 run216157 black
det1 run216108 red
det2 run216157 green
det2 run216108 blue
 

The EAR1 ratios of BCT/PKUP, BCT/SILI and PKUP/SILI plotted for each run for samples Si, Sinat goodfellow, Au20, Au22, Empty and Dummy. 

The ratios for BCT/PKUP for Si, Au20, Au22, Dummy, Empty and Sinat goodfellow have been plotted. Also included is the normalised counts (counts/BCT) with all 4 detectors on one plot. Apologies there is not a legend, however det1 is red, det2 is green, det3 black and det4 blue. 'counts' for Si was integreated over the Si resonance, for Au it was integrated over the largest resonance. For Dummy, Empty and Sinat the counts were integrated over a large range of 1e+5 to 1e+7ns. The Sinat resonance was too small for adequate statistics to only integrate over the resonance hence why a large range was used. 

Goodfellow Si-nat mounted at EAR1. First run: 116551

Goodfellow sample has been deposited on a single Mylar foil and glue is drying.

mass = 2.932 g

diameter = 20.0 mm

thickness = 3.98 mm

30Si
Mass: 0.9925(1) g;    Diameter: 22.22(1) mm;    Thickness: 1.77(4) mm;

natSi
Mass: 1.0653(2)g;    Diameter: 19.94(2) mm;    Thickness: 1.91(3) mm;

Mass of sample pre-treatment (sintering ...)

natSi 1.0238 g
30Si:  0.75034 g

EAR1: Si-nat sample fell off the holder during maintenance (before run 116544), appears intact and undamaged. Placed it back in-beam for further EAR1 measurements and subsequent transfer to EAR2.

EAR2: Replaced DUMMY with 30Si. Photo during alignment and photo of sample in holder attached.

8 sTED + 2 C6D6

C6D6: distance = 14 cm, angle = 135 degrees

sTED horizontal ring, distance for each detector from target = 4.5 cm. sTED labeled 8 in the DAQ is actually sTED #9 at n_TOF (actual sTED #8 showed no signal)

sTED1 809V, sTED2 793V, sTED3 813V, sTED4 779V, sTED5 785V, sTED6 800V, sTED7 791V, sTED8 837V

C6D61 (labeled C6D6_M in HV log) 854V, C6D62 (labeled C6D6_N in HV log) 871V

Default TTOFSort dead time setting of 30 ns is ok.

Calibration parameters for each detector:

A linear function was fitted to the reference point channel (from experimental histogram) and reference point energy (from simulation histogram). The reference point 'r' was r=mean+(FWHM/2) for a gaussian fitted to each compton edge. 

The comparrisons between the calibrated experimental and simulation histograms has been attached. P1 (left) and P2 (right) on the Y88 hisograms indicate whether the histograms were scaled with respect to the leftmost or rightmost compton edge (only to allow easier comparrison). 

Broadening parameters applied to the simulations

float a1 = 0.004947965;
float b1 = 0.005227974;
float a2 = 0.007163802;
float b2 = 0.007549987;
float a3 = 0.001256462;
float b3 = 0.006410511;
float a4 = 0.003907402;
float b4 = 0.004033837;

sigma= sqrt(axE+bxE^2) 

Both Au samples (20mm and 22mm) are single mylar.

Both Si30 (22mm) and natSi (20mm) are double mylar.

Empty is single mylar ONLY

Dummy is double mylar + glue 

New 22mm sample compared to old 20mm sample used at the beginning of the campaign + picture of dummy target in the setup.

Si Set up images and documentation.

Detector 1 - C6D6D: Distance= 9 cm, Angle= 135 deg relative to BL (check set up pdf for drawing if unsure), Voltage= 1550 V

Detector 2 - C6D6E: Distance= 9 cm, Angle= 135 deg relative to BL, Voltage= 1590 V

Detector 3 - C6D6H: Distance= 9 cm, Angle= 135 deg relative to BL, Voltage= 1450 V

Detector 4 - C6D6L: Distance= 9 cm, Angle= 135 deg relative to BL, Voltage= 1460 V

Note: Voltages were increased by 30V after the first few runs, these voltages are titled as "new voltages" in the DAQ when they were being tried out, and are now the final voltages.

Photos of the  68Zn(n,gamma) measuremement setup at n_TOF EAR-1.

Attached are the pictures of enriched Si-30 metal pieces.

Three aluminium crates contain 26Al(n, alpha) kit from EAR2, and was in the barracks (building 6547) near detector lab by EAR1 entrance. A list is attached and photos can be found on Dropbox:

https://www.dropbox.com/sh/68k1xove2zr1bmj/AADKvN8wR_Ia2EwZMOXZqdMCa?dl=0

Summary of work done so far.

Further investigation into dedicated and parasitic discrepancy.

Dedicated and parasitic discrepancy (Au 5eV resonance plateau) - quantified.

Flux and E_exc numalisation after sum WF.

Discrepancy between dedicated and parasitic pulses histograms in the 5eV gold resonance plateau region.

Corrected tof to En conversion.

E_excitation and flux normalisation of yield.

Proton consistency test (BCT, SiMon, weighted, unweigted, dedicated, parasitic) - Au cal1 and Se78
BG subtraction
TOF to En conversion
 

/eos/user/r/rugarg/public/2017_10_ng_ZnSe/

Latest 4 processing scripts:
1. process_runs_Au1_Jul20.C = Au runs (Se78 part), empty holder runs (Se78 part), and beam-off runs (Se78 part) processed with Au weighting function and set1 of calibration parameters.
2. process_runs_Au2_Jul20.C = Au runs (Se77 part), empty holder runs (Se77 part), and beam-off runs (Se77 part) processed with Au weighting function and set2 of calibration parameters.
3. process_runs_Se78_Jul20.C = Se78 runs, empty holder runs, beam-off runs, C runs, and filter runs processed with Se78 weighting function and set1 of calibration parameters.
4. process_runs_Se77_Jul20.C = Se77 runs, empty holder runs, beam-off runs, and filter runs processed with Se77 weighting function and set2 of calibration parameters.

My TTOFSort macro is located in

/afs/cern.ch/work/n/nsosnin/public/C6D6_Calibration/Calibration_Data/Calibrator.C

 https://docs.google.com/spreadsheets/d/1W1T2rC10UtOtrAaT8-ZAKFvX70v2PwDk_4-goYL-brI/edit?usp=sharing

Distance Sample to Detector: Det1: ~10.5 cm, Det2: 11 cm, Det3: 11 cm, Det4: 11 cm

77Se: m=0.9916 g; D= 20 mm

OLD: 77Se: m=0.919 g according to ntofdaq page. D~ 20 mm NEEDS TO BE CONFIRMED

78Se: m=1.989/pm0.001 g; D=20.09mm; t~1.7 mm

68Zn: m=1.998/pm0.001 g; D=20.02mm; t~1.39 mm