SCINTILLATOR → LIGHT GUIDE → PHOTOMULTIPLIER
Turn electrons
into a measured signal.
A researched connection plan for an Everhart–Thornley detector, with a concrete PMT module and clearly identified parts still to select.
TWO ELECTRICAL SYSTEMS. ONE OPTICAL LINK.
What connects to what
Electrical connections are a proposed architecture. The scintillator/cage setpoints remain examples until an assembly and supplies are specified. The colored light-guide line carries photons, not current.
High-voltage terminal-to-terminal connection schedule
| From | To | What must be verified |
|---|
Supply pin numbers, feedthrough flange, coating contact and insulation dimensions remain open because those parts are not selected. Commission this HV assembly with a qualified vacuum/HV engineer; the page is not an energization approval.
SPECIFIC TO HAMAMATSU H10722 SERIES
Six leads, no external PMT HV
The green wire is −5 V. The blue wire is an output.
Follow the revision supplied with your module. For voltage programming, insulate BLUE and use a bounded, ground-referenced source on WHITE. The manufacturer also shows a 10 kΩ potentiometer method; its 1.2 V reference can exceed the 1.1 V control limit at full travel, so monitor the wiper. Do not connect the scintillator’s +10 kV to any PMT module lead.
A COMPATIBILITY CHECK, NOT A GAIN CALIBRATION
Will this signal fit?
Vcont is checked against the datasheet limit. It does not retune the assumed anode current: a tube-specific gain calibration is still needed. These controls never change your microscope or BOM.
0 V4 V nominal limit
Vout ≈ |IA| × ZT
Transimpedance is output voltage divided by input current. The standard module has ZT = 1 V/µA. Above its specified swing, the ideal product is only the demanded voltage; it is not a real output prediction. Dark offset and overload recovery are omitted.
τ = 1/(2πf₋₃dB); t₁% = −τ ln(0.01) 20 kHz → 36.65 µs
For a single-pole approximation H(s) = 1/(1+sτ), the step error is exp(−t/τ). Solving for 1% error gives 4.605τ. Actual module/scan settling must be measured. This microsecond signal response differs from the module’s up-to-10-second gain-control settling specification.
ΔK = −qΔV = eΔV
For an electron q = −e, kinetic energy increases when it moves toward higher potential. Starting near grounded specimen potential, a +10 kV scintillator gives approximately 10 keV landing energy. The intermediate collector potential does not add another 250 eV to this endpoint difference. This energy calculation does not determine scintillator light yield.
Hover or focus a formula to read its derivation. Pixel dwell is not an antialiasing specification: sample the analog waveform sufficiently fast and filter before decimating into pixels.
ORDER OF WORK
From the bench to the chamber
RESEARCHED CANDIDATES & UNSPECIFIED HARDWARE
What you need to source
| Function | Part / specification | Status and selection work |
|---|
Before this can become a construction-ready wiring drawing
Specify the scintillator assembly and coating contact, light-guide/vacuum seal drawing, chamber flange, scintillator and collector supplies, cables/feedthroughs and ADC board. The PMT lead map above is verified for H10722; unidentified hardware cannot inherit its wiring.
The existing ESP32 sketch expects a conditioned signal at its internal ADC. It does not yet drive an ADS8681. Using that ADC requires its SPI readout and timing integration; use the scope to characterize the detector first.