Abstract
This paper presents designs for four types of very-low-velocity superconducting (SC) accelerating cavity capable of providing several MV of accelerating potential per cavity, and suitable for particle velocities in the range 0.006<v/c<0.06. Superconducting TEM-class cavities have been widely applied to cw acceleration of ion beams. SC linacs can be formed as an array of independently phased cavities, enabling a variable velocity profile to maximize the output energy for each of a number of different ion species. Several laboratories in the U.S. and Europe are planning exotic beam facilities based on SC linacs. The cavity designs presented here are intended for the front end of such linacs, particularly for the postacceleration of rare isotopes of low charge state. Several types of SC cavities have been developed recently to cover particle velocities above 0.06c. Superconducting four-gap quarter-wave resonators for velocities 0.008<{beta}=v/c<0.05 were developed about two decades ago and have been successfully operated at the ATLAS SC linac at Argonne National Laboratory. Since that time, progress in simulation tools, cavity fabrication, and processing have increased SC cavity gradients by a factor of 3-4. This paper applies these tools to optimize the design of a four-gap quarter-wave resonator for exotic beam facilities and othermore » low-velocity applications.« less
Highlights
The most efficient production mechanisms for slow radioactive ions yield ions in a 1 or a 2 charge state [1]
As we proposed in previous publications [2 – 4], a postaccelerator for radioactive ion beams (RIB) includes three
The ATLAS four-gap quarterwave resonators (QWR) built in the 1980s are operated typically at 3 MV=m accelerating field which corresponds to EPEAK 15:1 MV=m and BPEAK 360 G
Summary
The most efficient production mechanisms for slow radioactive ions yield ions in a 1 or a 2 charge state [1]. Low-charge-to-mass-ratio injectors have been proposed for this application [2 – 4] This type of injector is based on a low-frequency, cw radio frequency quadrupole (RFQ) injecting a very-low-velocity superconducting (SC) linear accelerator. The latter must be capable to accept and accelerate rare isotopes with charge-to-mass ratio in the range from 1=238 to 1=6. Superconducting four-gap quarter-wave resonators, known as ‘‘fork’’ or interdigital cavities, are a proven type of SC cavity for application in the energy range from 30 keV=u to 1:0 MeV=u [2]. We present designs for several types of four-gap quarter-wave resonant cavity optimized for present state-of-the-art superconducting materials and processing techniques.
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call