Transcript rfq - Chalmers

RFQ
A Radio Frequency Quadrupole (RFQ) is favored for low
energetic beams. It bunches, accelerates and focuses the ion beam.
The 4-vane REXRFQ accelerates the radioactive ions with a
charge-to-mass ratio larger than 1/4.5 from 5 keV/u to 300 keV/u.
• Theory
In principle an RFQ can be divided into
four sections: the radial matching section,
the shaper, the buncher, and the
accelerator section.
The 4-vane RFQ consists of four
electrodes, on which an alternating
voltage field is applied. The RF
quadrupole field provides transverse
focusing for the low energy ions while a
modulation of the spatial length of the
four rods performs smooth bunching of
the injected dc-beam and acceleration.
• Data
Energies Ein = 5 keV/u, Eout = 300 keV/u
Tank length L = 3 m
No. of cells: 232
Electrode voltage Vrod = 42 kV
Peak power consumption Wpeak = 53 kW
Shunt impedance R = 100 km
Beam direction
Q = 4000
Longitudinal phase spread = ±14%
RF
Longitudinal energy spread W/W = ±1.5%