Fusion Message Board

In this space, visitors are invited to post any comments, questions, or skeptical observations about Philo T. Farnsworth's contributions to the field of Nuclear Fusion research.

Subject: Re: Neutron detection, 5 (Multiple detectors?)
Date: Oct 04, 12:32 pm
Poster: Jim Lux

On Oct 04, 12:32 pm, Jim Lux wrote:

>On PMT's and large screens.... You might find a simple large diameter lens would be a pretty efficient means ot couple a small PMT to the larger screen. The only issue might be if there is a significant amount of UV in the screen's output. Then the lens would seriously attenuate unless it were quartz.

What about reflective losses off the lens surfaces?
>An array of PMT's is a bit of a challenge, but the PS requirements are very modest as to current. Just need to be aware of need for low ripple, since gain is VERY voltage dependent. Matching individual tube gains, though is another story. Need individual voltage controls to get them all set the same.

Of course, for neutron counting, we aren't really looking at pulse height, just that there IS a pulse at all, above a certain threshold, so you might not care that the gains aren't the same.