How do we calculate PMT bandwidth?

rise time of various pmt

HI,

How do we calculate PMT bandwidth? Should we use its rise time or the transit time between cathode or anode?

Thanks for your help!

Re: PMT Bandwidth

watertreader said:

How do we calculate PMT bandwidth? Should we use its rise time or the transit time between cathode or anode?

Click to expand...

It depends entirely on what you are using the tube for.

The transit time is going to define an upper limit which is well beyond the practical capability of most tubes. Transient response or rise time is generally going to give a far more realistic view of the performance.

John

Re: PMT Bandwidth

Hi,

I am a little confused over your explanation. From the data sheet that I seen, transit time is generally longer than the rise/transient time. Should transit time form the lower limit for the bandwidth performance instead?

Thanks for your response

Re: PMT Bandwidth

watertreader said:

HI,

How do we calculate PMT bandwidth? Should we use its rise time or the transit time between cathode or anode?

Thanks for your help!

Click to expand...

PMT stands for ??????????

Re: PMT Bandwidth

From the data sheet that I seen, transit time is generally longer than the rise/transient time.

Click to expand...

Yes that's also what I would expect with high speed PMT (photomultiplier tubes). I think, the above explanation isn't exactly correct. Clearly the signal rise/fall time defines the signal bandwidth.

But it's related to transit time in so far, that the transit time dispersion is one main source of non-zero rise/fall time. This strongly depends on field unformity and possible electron pathes with a particular PMT design. High speed tubes try to achieve a focussing of drifting secondary electron packets by a special field geometry.

Re: PMT Bandwidth

electronics_kumar said:

watertreader said:

HI,

How do we calculate PMT bandwidth? Should we use its rise time or the transit time between cathode or anode?

Thanks for your help!

Click to expand...

PMT stands for ??????????

Click to expand...

PMT stands for Photon Multiplier Tube.... apology for using the abbrievation