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: clarification (Mass spec)
Date: Aug 11, 11:31 am
Poster: Jim Lux

On Aug 11, 11:31 am, Jim Lux wrote:

>I am convinced that the only real test to find the extent of stripping vis-a-vis real D-D fusion in a Fusor or any plasma device would be to use a mass spectrograph. Since most of us don't have one sitting around in the garage, it would involve the following.

I seem to recall a mention in "the Bell Jar" about a quadrupole mass spec being refurbished, or built from scratch, by a determined amateur. The theory is simple (isn't it always) but I suspect the practice is far from trivial. However, hanging a mass spec, designed specifically for low mass ions, off an orifice from the fusor (so you can differentially pump the mass spec down real well) might not be all that much of a challenge (compared, say, to getting a calibrated neutron detector working?).

Would the best bet be to find a surplus RGA or Mass Spec and refurbish, or to build from scratch. The Mass Spec is going to be an "all things to all users" design, which might be non-optimal for the fusorites fairly narrow requirement. perhaps a qpole isn't the way to go? An older magnetic field sorter with multiple detectors might be better? Don't forget that the quadrupole essentialy scans over the range, only looking at a small area at any one time, so if your lone T or He3 happens to enter when the qpole is tuned to D or H, you've lost it. Much like a scanner radio looking for short burst signals... your probability of intercept is low.

The mass spec approach has the advantage of providing a definitive answer to the stripping vs fusion question