Monday, January 09, 2006

History of Prometheus

I removed relays K2 and K3 from the MO4 circuit board. They looked very dirty, I disassmbled one and found some copper pins were burn into black. I am not sure these relays can be used again after cleaning the dirty pins, I think it's better to use new relays. Unfortunately I have not reveived them from Newark.

Randy wrote down a report about Prometheus, the followed is the part about its history. Thanks Randy!
History of Prometheus (by Randy Carlson)

Prometheus is one of two identical amplifiers delivered to both Los Alamos and UIC in the spring of 1988 by Beta Development Corporation under Gary Loda (now deceased). The device consists of two main discharge cavities (10cm x 10cm x 2m long) that share a common x-ray pre-ionizer that operates at 150 kV. Originally, each main discharge electrode was driven by a two-stage saturable core compressor with the main voltage step-up achieved by a 6.33:1 Stangenes autotransformer. The prime energy store is at 25 - 30 kV and switched to each discharge side (called North and South) by a North and South bank of six Thyratrons. This design architecture was chosen by the manufacturer as a way to achieve ~ 1 Hz or more repetition rate operation and results in a final fast rising voltage pulse of 150 ? 180 kV on the main discharge anodes. At Los Alamos and UIC the discharge cavities were utilized in a folded series configuration except that Los Alamos used a XeCl based gas mixture at 3 atm and UIC uses a KrF based gas mixture at about 1.6 to 1.7 atm.

Shortly after installation, two main changes were made to the x-ray pre-ionizer: (1) the smooth conical epoxy bushing that had evidence of flashover was machined with grooves, and (2) x-ray masks were utilized in an attempt to control the area for main energy disposition in the laser cavity. The first of these changes is present in the UIC amplifier but as for the second change. Another area of change was the replacement of both stages of saturable cores and one set (an array of 80 ceramic capacitor stacks) with two Maxwell Rail Gaps. Both sides of the UIC amplifier have the Maxwell rail gaps installed and other than annual maintenance are working in a flawless fashion. The Los Alamos system was salvaged in the mid-1990s.

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