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GRID SEARCH – last news. Roberto Venturelli University of Padova and INFN, ITIS “G.Marconi”-Verona. Number of signals used Type of signals Tests with regular and irregular grids Last results New idea for minimization function. PSA team, Orsay, June 28, 2007. Number of signals used. - PowerPoint PPT Presentation
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Number of signals usedType of signalsTests with regular and irregular gridsLast resultsNew idea for minimization function
Roberto VenturelliRoberto Venturelli University of Padova and INFN,University of Padova and INFN,
ITIS “G.Marconi”-VeronaITIS “G.Marconi”-Verona
PSA team, Orsay, June 28, 2007
GRID SEARCH – last newsGRID SEARCH – last news
5
5.2
5.4
5.6
5.8
6
6.2
6.4
6.6
6.8
7
0 5 10 15 20 25 30 35
#Transients
FW
HM
at
1762
keV
(ke
V)
I suggest to have available all the segment signals, then every PSA code will get those significant transients with a proper mask
Number of signals usedNumber of signals used
Number of neighbour transients at the net charge signal assuming a simple geometrical point of view (about 10)
Number of neighbours obtained from a statistics of transients when the hit occurs in the segment base (about 18)
Analysis done using:• preamplifier signals • MWD signals (a first electronic response correction at LLP)
+ raw calculated signals
Type of signals used:Type of signals used:preampl. signals, MWD signals, currents, DWT coeff.,… ?preampl. signals, MWD signals, currents, DWT coeff.,… ?
preamplifier signalspreamplifier signals
MWD signalsMWD signals
current signalscurrent signals
MWD: how many poles needs to be corrected?MWD: how many poles needs to be corrected?
500ns 47s2nd pole 1st pole
preamplifier signals
MWD signals
The analysis with MWD signals improves the PSA performance
This format is already available at the local level processing, the calculated signals require an equivalent AA filter
All the signals need to be calibrated at every fold, with a time zero reference, possibly, time shifts between channels can be managed
I’m NOT confident with this minimization !!!
34416 26391 4164 32056
Tests with grids: regular and irregular Tests with grids: regular and irregular
At the moment the best result with my method is obtained with regular grid of 2mmWe have to continue the investigation to an irregular grid close to 1mm because there is something to gain ! (…limiting the processing time)
Tests with grids: regular and irregular Tests with grids: regular and irregular
Irregular Regular
1380
1380.5
1381
1381.5
1382
1382.5
1383
0 5 10 15 20 25 30
RUN#
Ene
rgy
peak
(keV
)
ge2
ge1
ge0C
AL
IBR
AT
ION
S
Improvements in Doppler Correction Improvements in Doppler Correction
Analysis restricted to a subset of events for change of position during calibrations
Improvements in Doppler Correction Improvements in Doppler Correction Internal calibration with segments
Core energyF=1 (4.4)F=2 (4.3)F=3 (4.3)
Segment energy 1st calibr.Energy shift
Segment energy 2nd calibr. F=1 (4.2)
Segment energy calibr. atF=2 (4.8)Not good!
At low energies and with high counting rate segments energy is preferable at core energy
The sum energy correction at fold 2 and more needs to be verified
These tests are PSA independent
The full calibration of the segments is a relevant step that has to be done before PSA
Other misunderstood problems are still present in the frontal part
Improvements in Doppler Correction Improvements in Doppler Correction
1.5
2
2.5
3
3.5
4
4.5
5
5.5
6
6.5
0 500 1000 1500 2000
FW
HM
(k
eV
)
energy (keV)
First experimental results AW
Subset analyzedInternal segments calibrationPSA with MWD signals
Last results
1381
Improvements in Doppler Correction Improvements in Doppler Correction
Subset analyzedSegments calibrationPSA with MWD signals
Doppler Correction versus ZDoppler Correction versus Z
3.6
3.8
4
4.2
4.4
4.6
0 1 2 3 4 5 6 7 8 9 10
FW
HM
(ke
V)
Z axis
These tests could help to study the quality of the calculated signals at different z and also the capability of the PSA method to identify positions
New chiNew chi22 minimization function minimization function
tminA
tmaxA tmaxA
tminA
Three different transient shapes
New chiNew chi22 minimization function: minimization function: ii
tt
aa
Measured signalsSignals associated at the 1st point in the base
Signals associated at the point in the base thatminimizes the function
After the first tests this method gives Dc of 4.5 keV @ 1382 keV