---------- Forwarded message ---------- Date: Tue, 30 Sep 1997 19:55:35 -0400 (EDT) From: richard hull To: hvlist@Anchorage.ab.umd.edu Subject: Farnsworth/Hirsch fusor (I) Warning, what follows is a teaser, but in time, will be fully divulged so that anyone whishing to make the device will have a number of postings to refer to. All, Well, all Tesla coil work....all planned electrometer revisions........all electrostatic investigations.....all planned activities of any sort are shoved so far back on the rear burners that they will need dusting off to proceed anew. What did this?? The Farnsworth/Hirsch fusor. At my Teslathon on September 12th, Tom Ligon showed up with his demostrator of the fusor. I had been corresponding and talking to tom over a few month prior to this and was most intrigued by what he was up to. Tom is an engineer, like myself, who like myself believes in the "hands-on imperative". He has been hired on and off as an engineering consultant by the famous Physicit R.W. Bussard. He notes that he is the "gravity boots" part of the team. Bussard is a top level theoretical physicist who has always had a place in his heart for the spherical focus reflex, recirculating, multipacting diode (Farnsworth/Hirsch fusor). The fusor in its basic configuration uses spherically focused, electrostatically accelerated, multipacting of ions, nuclei, electrons, what have you. Different pressure regimes, different gases, and diferent grid structures can give anything from simple ion multipacting, as in my current system and Tom's demo, to high end electron multipacting, right up to and including d-d fusion and neutron production on your kitchen table!!!!! Sound interesting? It is the perfect item for this list! Like fiddling with vacuum stuff? Change the oil in your pump, this project really sucks! Like plasma globes, glow discharges, plasmoid production? It'll blow you away!! Like high voltage work? Hold on to your insulators pal! Like mechanical structures, foraging for parts? Put on your scroungin' shoes! A little history: The spherical focus diode is old and goes back 60 years, but it never made a dent in the rectifier market. I never left the experimenter stage. Philo T. Farnsworth, inventor of electronic television. Had seen electron multipacting in his tubes early on in the 40s. multipacting is a term normally associated with electrons being recirculated between two plates in an extremely high vacuum at very high RF frequencies in pulsed modes of operation. This an odd occurance and very undesirable as the energy can build in the trapped electron plasmoid to a point where plates can melt and tubes can be destroyed. Farnsworth and others, on numerous occassions through the years, have announced this as a new discovery, each stumbling onto the odd conditions needed for electron multipacting. All, but Farnsworth saw the process as a thing to avoid ultimately. Farnsworth thought about the use of the energy contained in this multipacting system and in the late 50's began work on his "fusor". This device used no RF, but resurrected the old spherical focus diode and used pure DC for input. The recirculation of ions, nuclei, etc was gauranteed by the particular grid system in the fusor. Farnsworth Radio was bought out by ITT and Farnsworth begged a little lab space and funds to investigate fusion processes. He got an AEC license for Tritium and used a deuterium/tritium gas mix to generate as many as 10^8 neutrons/second with only 40KV accelerator input into a system at a pressure of 1-.1 microns (10-^3 to 10^-4 torr...not a particularly high vacuum). ITT ended the funding for the extremely modest program in the mid-late 60s. Here the fusor died until recently when George Miley of the Univ of Illonois and R.W. Bussard started the work up again............Again. with virtually zero budgets. Bussard works mostly out of pocket and Miley uses lab funds and grad students in "make busy projects" to further his work. I have my ion multipactor model in operation only two months after first hearing about the restart of Fusor work and two weeks after seeing my first fusor in operation. (I read the Farnsworth biography late last year) If you get to see one in operation, YOU WILL BE HOOKED! It is not a real easy project. It is not a real hard project. It is just right to challenge, entertain and inspire. This concept demostrator model can do nothing but intrigue anyone who builds it. It can, with only minor modification, additional vacuum stuff, and deuterium gas, produce neutrons in D-D fusion! More to follow: Richard Hull, TCBOR