[Amps] Tetrode amplifiers at LHC

[John Lyles]

Neat link. Tetrode-based RF drivers and associated ferrite-loaded acceleration cavities are the mainstay of most large proton and heavy ion synchrotrons. A brand new machine is being operated at KEK-JAERI in Japan, with multiple 500 kW tetrode amplifiers using TH558 devices - very large tubes. The CERN PS and PS booster are a pair of synchrotrons that provide the particle velocity that then travels into the SPS, their super-proton synchrotron. All of these machines have been running for years, with some modifications. Being able to sweep frequency rapidly, they use DC bias tuning coils on the ferrite cores. The amplifiers have either tunable input or broadband design, and the output is directly connected to the ferrite-filled resonator via loop(s). In the SPS, they use two huge amplifier arrangements, each having 4 combined 125 kW Thales (formerly Seimens) tetrodes, type RS2004J, driven by one. With this they get about 500 kW of CW power at 200 MHz.  These two are combined to get one
output even higher power. 

They also use big Klystrons at CERN in the actual LHC ring, the big one we hear about a lot these days. 

If you want to still work with high power tubes, big science is one of the few places still needing that technology (besides radar/military). 

73
John 
K5PRO

> Message: 5
> Date: Fri, 12 Sep 2008 12:20:20 +0000
> From: David G4FTC <g4ftc at hotmail.com>
> Subject: [Amps] Who said tubes were dead ........
> To: "amps at contesting.com" <amps at contesting.com>
> 
> It's still reasuring that the new LHC at CERN uses Tetrodes.
> 
> See
>  
> https://edms.cern.ch/file/445768/3/Vol3_Chap6_v3.pdf
> 

>
> David G4FTC
> _________________________________________________________________
>