Computations predicting RF cavity characteristics

Technical Report · Thu Sep 01 04:00:00 EDT 1988

DOI:https://doi.org/10.2172/378887· OSTI ID:378887

Jin, Y; Nicholls, G

The APS storage ring cavity is a single cell semi-spherical structure patterned along the lines of the KEK Photon Factory and the Daresbury cavities. The cavity was initially scaled to the APS frequency of 352.9 MHz using the computer code URMEL. Before construction of the prototype, it was considered essential to simulate the cavity as it would be measured in the machine shop as it was being built. The cavity has four large ports on the equator which would lower the frequency, but by how much? The code URMEL is only able to represent structures with rotational symmetry; MAFIA is three dimensional, and thus is able to simulate the actual structure. The first task was to determine what mesh size would be required using MAFIA to represent the structure in detail equivalent to that using URMEL. The computations not only give the effects of the ports on the frequency, but also a simulated tuner has been inserted into a port at various depths; thus, they have a prediction of a tuning curve. For each of the conditions, the first ten modes have been calculated, so they can see the effect of the tuner on the fundamental mode and also on the Higher Order Modes (HOM).

• Research Organization: Argonne National Lab., IL (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 378887
• Report Number(s): LS--124(ANL); ON: DE96015142
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
ADVANCED PHOTON SOURCE
CAVITY RESONATORS
COMPARATIVE EVALUATIONS
COMPUTERIZED SIMULATION
IMPEDANCE
M CODES
MESH GENERATION
OSCILLATION MODES
RF SYSTEMS
THEORETICAL DATA
U CODES