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: pulsing and potential well
Date: Nov 03, 4:54 pm
Poster: Richard Hull

On Nov 03, 4:54 pm, Richard Hull wrote:

Everyone should read Jim's words over again below. They are well spoken.

Bob Hirsch told me the real bad ideas all go at fusion with huge machines and big budgets in the vain attempt to hit the break even thing........ always needing just a bit more power.....and real soon now! Pretty soon you have a leviathon which is out of control. Real good fusion schemes should, ideally, not need giant systems to work.

LLNL's laser fusion effort is virtually totally de-railed now and in a shambles. Never have so many overpaid bureau-scientificrats contributed so little for so much in the money to benefit so few.

Richard Hull

>It seems to me that the pulsing is to overcome the practical problems of such high currents: the grid can't take the sustained power and will melt; and generating sustained currents of many amps at several hundred kV in a lab is very expensive. If you are just trying to find out if it will work at all, then doing it for a millisecond at a crack is plenty long enough to reach steady state. Megawatt pulse powers (and low average powers) are easy, megawatt continuous powers are expensive.
>You'll observe that for all of the "fusion power too cheap to meter" schemes (including commercialization of the Farnsworth unit, except as a neutron source), everyone proposes that "there is a nonlinear relation between power out and power in, and if only we can make the box big enough, with enough input power, we'll get over the breakeven level, and be generating more than we feed in." Generally, there are reasonably sound physics reasons why this is theoretically true. (sometimes overlooking practical details like that you'll need the entire world resources of Vanadium to make the thing)
>Of course, the "in 2 (or 5, or 10, or..) years, we'll have enough input power to reach breakeven" statement has been made many a time over the past 30 years. Nobody even claims that the big laser inertial confinement thing is to generate power anymore, but rather, it's for "stockpile stewardship."