detectors and cross talk presented below are cross talk measurements carried out on 2 burle and 1...
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Detectors and Cross Talk
Presented below are cross talk measurements carried out on 2 Burle and 1 Hamamatsu MCP PMTs and 1 Hamamatsu MultiAnode PMT (MAPMT).
Cross Talk
MCP PMTs H9500 MAPMT
Conclusions
Cross Talk in Position Sensitive Photon Detectors Rachel Montgomery* on behalf of the PANDA Cherenkov group
Burle 85011 Burle Prototype Hamamatsu SL10
Pore size (µm) 25 10 10
Number of pixels 8 x 8 8 x 8 4 x 1
Active area (mm2) 51 x 51 51 x 51 22 x 22
Total area (mm2) 71 x 71 69.5 x 69.5 27.5 x 27.5
Geometrical efficiency 0.44 0.47 0.61
Peak quantum efficiency At 400nm At 400nm At 300nm
Table 1: Properties of the MCPs which were tested.
Hamamatsu H9500
Pixel size (mm) 2.8 x 2.8
Number of pixels 16 x 16
Active area (mm2) 49 x 49
Total area (mm2) 52 x 52
Geometrical efficiency 0.89
Peak quantum efficiency At 350nm
Table 2: Properties of the H9500 MAPMT.Figure 6: Hamamatsu H9500 PMT.
The H9500 dynodes are arranged horizontally across the PMT face –
does this make a difference? Figure 7: Close up of the H9500 face,
indicating dynode orientations.
One Pixel
Horizontal
Vertical
>1 dynode chains
Acknowledgements and thanks to Albert Lehmann, Universitaet Erlangen-Nuernberg, for his MCP cross talk studies.
One pixel is illuminated with light, false signals are obtained from non-
illuminated pixels
Timing resolution maybe degraded and
position information compromised
ResultsOnly vertical laser
scans exhibited symmetry in
cross talkpatterns.
RESULTS:
Rather homogenous response and
significant cross talk.
Burle 85011 Burle Prototype
Figure 4: Cross talk results for Burle 85011 and Burle prototype MCP’s.
Less homogenous response and
even more cross talk.
Figure 5: Surface scan cross talk results for Hamamatsu SL10 MCP.
SL10 MCPVery
homogenous response
from individual channels.
Significant cross talk between channels.
• Laser scans show dynodes affect cross talk pattern shapes and symmetry during horizontal scans.
• Non-optical cross talk was observed.
Cross Talk: H9500 PMT• Surface scans indicated smaller pore sizes yield more cross talk.
• The Hamamatsu SL10 displayed the most homogenous response.
Cross Talk: MCP PMTs• Inherent property of position
sensitive photon detectors.• Studied in 3 MCP PMTs and 1
MAPMT.
Cross Talk
Single photon sensitivity in 2T magnetic fields
Sufficient position resolution
Excellent timing resolution (<50ps single photons)
High photon rate stability
(MHz)
Photon Detector Requirements
for PANDA Disc DIRC
Candidates include: microchannel plate (MCP) photomultiplier tubes (PMTs) and MultiAnode PMTs. Resulting applications include medical imaging.
MCP PMTs: MAPMT:
Horizontal and vertical laser scans highlighted different cross talk patterns caused by arrangement of dynodes.
Horizontal
Figure 7 Figure 8
Vertical
Figure 8: Typical cross talk patterns obtained from horizontal and vertical scans.
Figure 9: Cross talk pattern symmetry observed during vertical scans.
Figure 9 Figure 10
Above scanned
pixelBelow
scanned pixel
* E-mail: [email protected]
Figure 3: Hamamatsu
SL10.Figure 1: Burle 85011.
Figure 2: Burle Prototype.
RESULTS:
Figure 10: Oscilloscope trace showing non-optical cross talk in 2 illuminated pixels.
Oscilloscope measurements allowed observation of non-optical cross talk in the form of a secondary peak with constant timing.