The problem with double event patterns (M. Brusa, K. Dennerl – MPE) EPIC CAL/OPS meeting - MPE

Classification of doubles readout direction split right (SAS: „2“) split left (SAS: „4“) split forward (SAS: „3“) split backward (SAS: „1“) SAS 2 Right SAS 3 Forward SAS 4 Left SAS 1 Backward Forward/Backward doubles: superposition of “true” doubles and “false” doubles (re-emission during read-out)  cause shifts in energy calibration

SAS 2/4: (Left/Right doubles) resemble singles in illumination SAS 1/3: (Forward/Backward doubles) different illumination  the amount of forward and backward doubles vary across the detector

11 CALCLOSED observations (PN + FF + expo > 20 ks) spanning ~1000 revolutions from #84 to #1105 Spectra extracted in 120 different positions (30x4 quadrants) for - SINGLES (PATTERN=0) - DOUBLES (PATTERN=1-4) XSPEC: fit of the MnKα line (5.896 keV) and Al line (1.486 keV) tested against: - different matrices or models used - singles vs. doubles - backward vs. forward - MnKα vs. Al Q0Q1 Q3 Q2

Examples of spectra (MnKα, Rev. #572, Q1) Singles (black) D-backward (red) D-forward (green) readout direction

Singles, Q1 Single gaussian fit to MnKα REV #84 Mn line (5.896 keV)

Singles, Q1 REV #125 Mn line (5.896 keV)

Singles, Q1 REV #249 Mn line (5.896 keV)

Singles, Q1 REV #429 Mn line (5.896 keV)

Singles, Q1 REV #981 Mn line (5.896 keV)

Singles: different MATRICES used Best fit energy line does not depend on the actual matrix used Singles: different MATRICES used REV #84

Singles: different MODELS used Best fit energy line does not depend on the model used REV #84

Singles vs. Double (1 – backward) REV #84 Systematic trend  Position of SAS”1” inconsistent with values for the singles Singles (blue) D-backwards (red) readout direction

Singles vs. Double (1 – backward) REV #125 Systematic trend  Position of SAS”1” inconsistent with values for the singles Singles (blue) D-backwards (red) readout direction

Singles vs. Double (1 – backward) REV #572 Singles (blue) D-backwards (red) readout direction

Singles vs. Double (1 – backward) REV #857 Singles (blue) D-backwards (red) readout direction

Singles vs. Double (1 – backward) - “detector representation” - REV #84 “Curved shape” wrt singles Singles (blue) D-backward (red)

Singles vs. Double (1 – backward) REV #125 Systematic in all observations

Singles vs. Double (1 – backward) REV #249 Systematic in all observations

Singles vs. Double (1 – backward) REV #309 Systematic in all observations

Singles vs. Double (1 – backward) REV #429 Systematic in all observations

Singles vs. Double (1 – backward) REV #572 Systematic in all observations

Singles vs. Double (1 – backward) REV #605 Systematic in all observations

Singles vs. Double (1 – backward) REV #709 Systematic in all observations

Singles vs. Double (1 – backward) REV #857 Systematic in all observations

Singles vs. Double (1 – backward) REV #981 Systematic in all observations

Singles vs. Double (1 – backward) REV #1105 Systematic in all observations

Singles vs. Double (backward) vs. Double (left) REV #125 Singles (blue) D-backward (red) Singles (blue) D-left (red)

Singles vs. Double (backward) vs. Double (forward) REV #125 No clear trend seen! Singles (blue) D-backward (red) Singles (blue) D-forward (red)

Al line Singles vs. Double (1 - backward) REV #125 Singles (blue) D-backward (red)

Mn vs. Al lines (singles vs Double 1- backward) REV #125 Smaller amplitude..but similar shape! MnKα line Al line

Conclusions/Future developments Singles: - Mn & Al line energy quite stable (in single observation) - Matrices/models adopted does not affect energy determination Doubles: - most of problems caused by BACKWARD (systematic trend wrt to singles) - LEFT/RIGHT: similar to singles - FORWARD: no systematic trend… Amplitude in Al line smaller than in Mn line -  Energy AND spatial corrections needed