1.  Number of signals used  Type of signals  Tests with regular and irregular grids  Last results  New idea for minimization function Roberto Venturelli University of Padova and INFN, ITIS “G.Marconi”-Verona PSA team, Orsay, June 28, 2007 GRID SEARCH – last news

2. 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 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)

3. Analysis done using: preamplifier signals MWD signals (a first electronic response correction at LLP) + raw calculated signals Type of signals used: preampl. signals, MWD signals, currents, DWT coeff.,… ? preamplifier signals MWD signals current signals

4. MWD: how many poles needs to be corrected? 500ns47  s 2 nd pole 1 st 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 !!!

5. 3441626391416432056 Tests with grids: regular and irregular

6. At the moment the best result with my method is obtained with regular grid of 2mm We 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 Irregular Regular

7. CALIBRATIONS Improvements in Doppler Correction Analysis restricted to a subset of events for change of position during calibrations

8. Improvements in Doppler Correction Internal calibration with segments Core energy F=1 (4.4) F=2 (4.3) F=3 (4.3) Segment energy 1 st calibr. Energy shift Segment energy 2 nd calibr. F=1 (4.2) Segment energy calibr. at F=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

9. Improvements in Doppler Correction FWHM (keV) energy (keV) First experimental results AW Subset analyzed Internal segments calibration PSA with MWD signals Last results 1381

10. Improvements in Doppler Correction Subset analyzed Segments calibration PSA with MWD signals

11. Doppler Correction versus Z FWHM (keV) 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

12. New chi 2 minimization function t minA t maxA t minA Three different transient shapes

13. New chi 2 minimization function:  i tttt aaaa Measured signals Signals associated at the 1 st point in the base Signals associated at the point in the base that minimizes the function  After the first tests this method gives Dc of 4.5 keV @ 1382 keV