Simon,

 

Apologies for the delay but yesterday turned out to be rather busy.

 

Attached are 3 files with the FETS RFQ parameters. The first file (FETS
RFQ TTF.data) contains the design parameters as derived using the
analytical two-term potential function. The second file (FETS RFQ
modified.data) contains the parameters after adjustment to give the same
focussing and acceleration but taking into account the actual vane tip
shape. In principle the second file is what we'd make. The third file is
a spreadsheet which just contains the same data.

 

The columns in the text files are:  a(mm), m, rho, cell length (mm),
voltage (kV), synch phase (deg) and synch energy (MeV). The phase is the
entrance phase at the beginning of a cell and the energy is at the exit
energy at the end. Rho is the pole tip transverse radius. When this is
negative it represents a percentage of the mid-cell radius r0 (ie 100 *
rho / r0), when it is positive it represents an absolute value in mm.

 

Each line of the file is a cell which is half a period of modulation.
The modulation starts such that the first horizontal cell goes from a to
ma whereas the first vertical cell goes from ma to a. This can be a
little confusing as the first cells are actually un-modulated! The very
first cell in the file is the tapered radial matching cell which is the
length of 4 normal cells.

 

Let me know if anything is unclear or you need anything else.

 

Alan

 

Alan Letchford 
ISIS Injector Group Leader
STFC Rutherford Appleton Laboratory
HSIC, Didcot, Oxon., OX11 OQX, UK
Tel: + 44 1235 446122 Mob: +44 7710 255934 


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