photomultiplier simulation

[JOSEALB85]

Hi,

I'm starting doing some simulation and i want to simulate a Photomultiplier device. Has someone done anything related??

Regards...

Jose A Morales de los Rios

[yyao]

Hi Jose,

I have worked with PMTs (photomultiplier tubes) in a previous life, and have modeled them in simulation with satisfactory results. We don't have any PMTs in the Multisim database, but I can offer you my experience in modeling a PMT.

Depending on the context of your design, there may be a few parameters of the PMT you want to model. First off, most PMTs are high voltage devices with very large impedances. You can model a PMT with a AC_VOLTAGE source with its Voltage (Pk) and Voltage Offset parameters set to what you find in the datasheet or what you measure in the lab. Place a large resistor (typically > 100 kilo-ohm) in series with the voltage source. If you want to model dark current, you can place a DC_CURRENT component in series as well. Typically, PMTs are low pass devices and it may be sufficient to place a capacitor on the output to model the bandwidth of the system. These parameters, output impedance, dark current and bandwidth, can be found in the datasheet of the PMT.

To help modularize your design, you might want to place these components in a subcircuit or hierarchical block which you can reuse multiple times throughout your design.

Provided that you don't drive them to saturation, this may be a good model to start with in testing your system's bias and frequency and transient response.

Message Edited by yyao on 11-20-2009 09:27 AM

[Minikisscool]

Hi,

I am interresting by your project.

I am working on simulation of PMT et I am using exponentiel pulse.

Have you finished one or more simulation of PMT ?

Thanks

[P.E.]

Well, but does not this describe just a DC performance of the PMT?

As you know PMTs are corrent sources the provide more or less short pulses with amplitude that has certain staistcs.

The pulse width and shape then determines spertal content of the signal, which is then relevent for downstrem electronics.

Woudl that be possible to model with Simulink? What does NI say to that?

Thanks.