The different elements that can be found on each RF plant are: RF Amplifier (IOT), CaCo (Cavity Combiner), Circulator, Waveguide System, Cavity and Low Level RF.

 

IM-ACCELERATORS_RFSystem2

 

The main parameters of the RF system of the ALBA SR and Booster are summarized in following table.

  Booster   Storage Ring 
Frequency 499.654 MHx
# Cavities 1 6
RF voltage per cavity 1000 kV 600kV
Energy loo per turn 627keV/turn 1.3MeV/turn 
RF Power per cavity 35 kW 150kW
RF Transmitter 1 x 80 kW 2 x 80kW
Synchrotron frequency 9.4 – 13.7 kHz 1.5 - 9.5 kHz
Overvoltage factor - q 2.5
Maximum Current 4 mA 400 mA

  

IOT: RF AMPLIFIER

 

 

CaCo: CAVITY COMBINER

  

CIRCULATOR

 

WAVEGUIDES AND WATRAX

  

STORAGE RING CAVITY: DAMPY

Dampy cavities are based in the normal conducting HOM damped cavity designed by BESSY (Germany) following the EU design. Their main parameters are:

 

BOOSTER CAVITY

The booster cavity is based on the 5-cell Petra-II cavity design and its main parameters are:

 

DIGITAL LOW LEVEL RF

The main task of the Low Level RF is to control the RF Voltage of the cavity, keeping its phase and amplitude constant respect to the beam. Commercial digital boards with fast ADCs, DACs and FPGA processor have been used to implement this signal. It also keeps constant the resonance frequency of the cavity by moving a plunger inwards/outwards the cavity body to compensate thermal drifts.


The main parameters of this system are:

  Digital boards

Lyrtech VHS-ADAC:

-8 ADCs, 80MHz, 14 bits
-8 DACs, 80MHz, 14bits
-FPGA Virtex-4 SX55

Based on IQ Modulation/demodulation technique
Amplitude loop resolution < 1% peak to peak
Phase Loop Resolution < 1º peak to peak
Loops bandwidth > 10kHz
Dynamic range > 30dB
Extra utilities

- Automatic startup
- Automatic recovery with beam
- Fast Data Logger
- Automatic conditioning