the problem with double event patterns (m. brusa, k. dennerl – mpe) epic cal/ops meeting - mpe
Post on 02-Jan-2016
23 Views
Preview:
DESCRIPTION
TRANSCRIPT
Classification of doubles
read
out
dir
ect
ion
split right(SAS: „2“)
split left(SAS: „4“)
split forward(SAS: „3“)
split backward(SAS: „1“)
SAS 2Right
SAS 3Forward
SAS 4Left
SAS 1Backward
Forward/Backward doubles:superposition of “true” doublesand “false” doubles (re-emissionduring 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
Q0 Q1
Q3 Q2
Examples of spectra (MnKα, Rev. #572, Q1)
Singles (black)
D-backward (red)
D-forward (green)
readout
dir
ect
ion
Singles: different MATRICES used
Best fit energy line does not depend on the actual matrix used
Singles: different MATRICES used
REV #84
Singles vs. Double (1 – backward)
REV #84
Systematic trendPosition of SAS”1”inconsistent with values for the singles
Singles (blue)
D-backwards (red)
readout
dir
ect
ion
Singles vs. Double (1 – backward)
REV #125
Systematic trendPosition of SAS”1”inconsistent with values for the singles
Singles (blue)
D-backwards (red)
readout
dir
ect
ion
Singles vs. Double (1 – backward)- “detector representation” -
REV #84
“Curved shape”wrt singles
Singles (blue)
D-backward (red)
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)
Mn vs. Al lines (singles vs Double 1- backward)
REV #125
Smaller amplitude ..but similar shape!
MnKα lineAl 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
top related