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Shootout experiment GSFMA315 at a glance
122Sn(40Ar[170MeV],4n)158Er
12C(84Kr[394MeV],4n)92Mo
GS GT
1:Mo,Tu
2:Tu,We,Th3:Th,Fr
4:Sa
Highmultiplicity
Large v/c ~8.5%
Normalkinematicsv/c=2.2%
Inversekinematics
4/21-26/2014
First look 92Mo case, just ‘quality’Normalize on the high energy tail
Tracked GTSpectra FOM<0.8
Look closer
92Mo case: energy resolution in GT is much better at 2 MeV
FWHM inGT at 2 MeVis ~7.8 keV
Simple GS root sort GS sort using side channels
Double gated spectra (GT not full statistics)
92Mo case in GT: tracked, CCsum using mode 2 information and CCsum using just center of crystal position
GT resolution for the 2065 keV line in 92Mo
GTFWHM8.7 keV
or 0.42%
Participants (>40)
[email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected]@umd.edu
(PI)[email protected], [email protected], [email protected], [email protected], [email protected], [email protected], (PI)[email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected],
EXTRA EXTRA EXTRA EXTRA.....
Using60Co
source dataafterrun
Preliminary!!(normalization
problems)
Normalize to 1 hour of beam time;158Er case, ‘standard setup’
for93 GS detectors28 GT crystals
GS coverage ~80%GT coverage ~22%
GS norm needs to be redone
Normalize to 1 hour of beam time;92Mo case, ‘standard setup’
for93 GS detectors28 GT crystals
GS coverage ~80%GT coverage ~22%
Not resolved
GS norm needs to be redone
Re-normalize GT to have the same coverage as GS (~80%) from its current coverage of ~22%This scaling is not proper as more GT modules
makes the tracking (much) better
Gretina spectra are lower limits
Normalize to the currents
84Kr beam charge state is 19+
40Ar beam charge state is 9+
GT, 92Mo, run 75, 0.1 pna
GS, 92Mo, run 21 _000, 15-16 ena/19 = 0.8 pna (X8 faster)
GT, 158Er, run 148, 5 ena/9 = 0.55 pna
GS, 158Er, run 22 _000, 25ena/9 = 2.7pna (X4.9 faster)
:: The DAQ limits the current we can handle in GT
If we just scaled to the beam current GS can handle then we would see
:: With a faster DAQ, GT could compete with GS with only 22% coverage vs the GS coverage of 80%
Sum of gates in GS and GT for 158Er, normalized to high energy tail. Single interactions are included in the tracking, FOM<0.8
Peak to background issues158Er case: Find the background spectrum (blue) for the sum of
gated spectra for GS and GT
GT sum of gatesspectrum
Then produce sum of gates divided by the smooth background == “a peak/background” measure
GAMMASPHERE
GRETINA
Gammasphere
GRETINAStandard decomp
GRETINASingle fit per segment decomp
Still having problems with the decomposition: Check the ‘radius’ spectrum. 60Co data taken at MSU (blue) and ANL after the shootout run (red). The ANL spectrum looks better, the new basis puts more points between boundaries and less localized points near boundaries
MSU
ANL
Same decompfunction! Butnew basis at ANL
New basis is better!!
We have the option to replay the mode3 data we took!Re-decomposed 158Er data, FOM<0.8red=oldblue=new
Slightly better; but the FOM distribution can be different so...
We restrict decompositionfits to only have one interaction
per segment
Re-decomposed 158Er data, FOM spectrumNon trivial FOM seems to improve a little!but counts in 0 (single hits) are also different (4.3x10^7 vs 1.1x10^7)
Old New
Max at 3.1Max at 0.27
‘Radius plot’, for all interaction points. (this is a plot of the distance from the target
for all interaction points the decomposition found)
Old New
What is actually better?New spike
Radius spectrum for first interaction points according to tracking program
newold
Gamma ray multiplicity distributions
Old New
The fifth leg: the 166Ho source
Lew Riley added stationary source to UCGRETINA! Need 18 levels to simulate
We can compare some real data to the GEANT4 simulated data that we took a few months ago
We only had 6 detectors at that time, and there was no target chamber
We send real data and GEANT4 simulated data through the same tracking; the G4 data after realistic packing of
interaction points and smearing of positions and energy
Preliminary analysis:
Higher energies
The continuum is really well reproduced!Does this mean that there is a future forcontinuum spectroscopy using GT or AGATA?
Low energy region, ICC added to G4 spectra by hand
The 184 keV is much better; but the 81 keV lineIs cut by some thresholds in GT. The extra lines in the G4 spectrum gets stronger at low energiesfor some reason
First look at 158Er, just ‘quality’::normalize on the high energy tail
Tracked GTSpectra FOM<0.8
Shootout experiment; gsfma315 4/21-26/2014
The PROPOSAL was: We propose to firmly establish the performance of the decomposition and gamma--ray tracking algorithms by comparing the GRETINA to
the Gammasphere gamma--ray detector array, under the same conditions, using the following two reactions
The two reactions are complementary. Indeed, the first reaction will allow us to extract the performance of the decomposition and tracking
algorithms at high gamma--ray multiplicity at a moderate recoil velocity. The second reaction will allow us to evaluate the Doppler reconstruction capability, based on tracking, in the case of high recoil velocities, but at a
moderate multiplicity of gamma rays. The experimental results will be compared to GEANT4 Monte Carlo simulations.
122Sn(40Ar[170MeV],4n)158Er
12C(84Kr[394MeV],4n)92Mo
GT resolution for the 2065 keV line in 92Mo