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: Ceramic caps
Date: Oct 29, 11:47 pm
Poster: Pierce Nichols

On Oct 29, 11:47 pm, Pierce Nichols wrote:

>Seriously, for the type of pulse system Mr. Nichols is talking about, 50-60kV is a good introductory level. I would use a resonantly charged system, which will get you nearly 2X the input voltage if done right, with a charging inductor, blocking rectifier, a single cap, and a thyratron or triggered spark gap to fire off the whole mess. Winding the charging inductor could be a small challenge, but using a fair sized silicon steel cut core will help make the inductor more compact. The inductor will need to be wound in 5-6 sections to reduce capacitance and provide voltage grading, and the beast can be then be plopped into a can of oil. The bobbin for said cut core could be fashioned out of FR-4 sheet or thick mylar. I'm looking at a similar setup to fire my copper halide laser, sans oil, since I'm only dealing with 10 kV.

How exactly does a rig like this work? I'm having some trouble envisioning it. Do you put the cap and inductor into resonance somehow? Do you use and AC input or what?
Based on (primarily) on the responses here and (secondarily) on my continuing research, I've decided to scale back my ambitions... for the time being .
I'm thinking of going with the pulse transformer idea someone else suggested -- it extends the rise time , and introduces the possibility of ringing in the discharge circuit, but sounds like it's easier to design and build than a Marx generator. It also requires only one sparkgap, and one that it looks like I can afford to buy a professional one at that voltage. Finally, it appears I can then get away with cheaper and lower-voltage caps and the charging supply won't be so evil and expensive -- maybe even just a pole-pig hooked into a full-wave rectifier and a filter cap .