Shootout experiment GSFMA315 at a glance 122 Sn( 40 Ar[170MeV],4n) 158 Er 12 C( 84 Kr[394MeV],4n) 92 Mo GSGT 1:Mo,Tu 2:Tu,We,Th 3:Th,Fr 4:Sa High multiplicity Large v/c ~8.5% Normal kinematics v/c=2.2% Inverse kinematics 4/21-26/2014

First look 92 Mo case, just ‘quality’ Normalize on the high energy tail Tracked GT Spectra FOM<0.8 Look closer

92 Mo case: energy resolution in GT is much better at 2 MeV FWHM in GT at 2 MeV is ~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 92 Mo GT FWHM 8.7 keV or 0.42%

Participants (>40)

EXTRA EXTRA EXTRA EXTRA.....

Using 60 Co source data after run Preliminary!! (normalization problems)

Normalize to 1 hour of beam time; 158 Er case, ‘standard setup’ for 93 GS detectors 28 GT crystals GS coverage ~80% GT coverage ~22% GS norm needs to be redone

Normalize to 1 hour of beam time; 92 Mo case, ‘standard setup’ for 93 GS detectors 28 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 Ar beam charge state is 9+ GT, 92Mo, run 75, 0.1 pna GS, 92Mo, run 21 _000, 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 issues 158Er case: Find the background spectrum (blue) for the sum of gated spectra for GS and GT GT sum of gates spectrum

Then produce sum of gates divided by the smooth background == “a peak/background” measure GAMMASPHERE GRETINA Gammasphere GRETINA Standard decomp GRETINA Single fit per segment decomp

Still having problems with the decomposition: Check the ‘radius’ spectrum. 60 Co 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 decomp function! But new basis at ANL New basis is better!!

We have the option to replay the mode3 data we took! Re-decomposed 158 Er data, FOM<0.8 red=old blue=new Slightly better; but the FOM distribution can be different so... We restrict decomposition fits to only have one interaction per segment

Re-decomposed 158 Er data, FOM spectrum Non 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 3.1 Max 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 new old

Gamma ray multiplicity distributions Old New

The fifth leg: the 166 Ho 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 for continuum 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 line Is cut by some thresholds in GT. The extra lines in the G4 spectrum gets stronger at low energies for some reason

First look at 158 Er, just ‘quality’:: normalize on the high energy tail Tracked GT Spectra 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. 122 Sn( 40 Ar[170MeV],4n) 158 Er 12 C( 84 Kr[394MeV],4n) 92 Mo

GT resolution for the 2065 keV line in 92Mo