The RF System of Thomx

The RF system of the ThomX electron storage ring consists in a 500 MHz single cell copper cavity of the ELETTRA type, powered with a 50 kW CW solid state power amplifier (SSPA), and the associated Low Level RF feedback and control loops. The low operating energy of 50/70 MeV makes the impedances of the cavity higher order modes (HOMs) particularly critical for the beam stability. Their parasitic effects on the beam can be cured by HOM frequency shifting techniques, based on a fine temperature tuning and a dedicated plunger. A typical cavity temperature stability of ± 0.05°C within a range from 30 up to 70 °C can be achieved by a precise control of its water cooling temperature. On the other hand, the tuning of the cavity fundamental mode is achieved by changing its axial length by means of a motor-driven mechanism. A general description of the system and the state of its progress are reported together with some considerations of the effects of beam cavity interactions.

cavity
HOM
controls
feedback
storage-ring

References(12)

Figures(0)

[1]

The ThomX Project

A. Variola

[2]

ThomX CDR, IN2P3-00448278

[3]

500 MHz cavities for the Trieste synchrotron light source Elettra

A. Massarotti

[4]

- https://indico.desy.de/getFile.py/access?contribId=127&sessionId=9&resId=0&materialId=poster&confId=3391

[5]

First Tests of a HOM-damped high power 500 MHz Cavity

F. Madhouse

[6]

Development of a high-power RF cavity for the PEP-II B factory

R.A. Rimmer

[7]

Improvements in curing coupled bunch instabilities at ELETTRA by mode shifting after the installation of the adjustable higher order mode frequency shifter (HOMFS)

M. Svandrlik
,
A. Fabris
,
C. Pasotti

[8]

- http://www.ansys.com

[9]

- http://www.cst.com

[10]

Simulations and RF Measurements of the Fundamental and Higher Order Modes of the ThomX 500 MHz Cavity

M. El Khaldi

[11]

Developments of High Power Solid State Amplifiers at SOLEIL

P. Marchand

[12]

Transverse feedback development at SOLEIL

R. Nagaoka