[ARC5] DARPA announces new program to improve vacuum tube performance----really!

Tue Aug 11 19:08:29 EDT 2015

Back in the mid 1980's IIRC the military made available a very large pot of cash to do two things, to write software to do the electron ballistics needed to design high performance vacuum tubes such as traveling wave tubes magnetrons and gyrotrons, and to financially support college professors and grad students to turn out new generation of tube designers.
>From what i can tell this has worked out well.  Since that was a generation ago, this seems to me to be an effort to bring forth the next generation of devices and designers.
Similarly many years ago I heard of work modernizing vacuum device design using semiconductor fabrication techniques.  For example use silicon anisotropic etching to create a bed of nails, field emission electron emitter to replace the filament thereby enabling high performance vacuum-electron devices using more or less conventional semiconductor and nano-fabrication techniques.
Because the electron emitter-grid-plate spacing can be made very small and very uniform these hypothetical devices would work with transistor type operating voltages but- in the specific case I remember- much better RF linearity and overload performance.
So i have no idea wheeze all of this is going to go but I like the idea that people are still thinking about designing and making useful devices that employ electrons flowing in a vacuum
bruce

      From: J Mcvey <ac2eu at yahoo.com>
 To: Bruce Long <coolbrucelong at yahoo.com>; Ian Wilson <ianmwilson73 at gmail.com>; Peter Eijlander (PA0PJE) <pa0pje at xs4all.nl> 
Cc: "Arc5 at mailman.qth.net" <Arc5 at mailman.qth.net> 
 Sent: Tuesday, August 11, 2015 6:46 PM
 Subject: Re: [ARC5] DARPA announces new program to improve vacuum tube performance----really!

You can't make this stuff up!

     On Tuesday, August 11, 2015 6:29 PM, Bruce Long via ARC5 <arc5 at mailman.qth.net> wrote:

 OK somewhat off topic and you are never going to use one of these new tubes in a receiver project but still - I think- of interest:
DARPA wants to transform vacuum electronics for superior communications, data transmissions
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| DARPA wants to transform vacuum electronics for superio...The notion of vacuum electronics may sound ancient in high-tech terms but a new program from the scientists at the Defense Advanced Research Projects Agency aims... |
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| View on www.networkworld... | Preview by Yahoo |
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The tube shall rise again.
bruce  KJ3Z

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