Coupled-cavity Drift-tube Linac Research Articles

Physics design of a CW high-power proton Linac for accelerator-driven system

Accelerator-driven systems (ADS) have evoked lot of interest the world over because of their capability to incinerate the MA (minor actinides) and LLFP (long-lived fission products) radiotoxic waste and their ability to utilize thorium as an alternative nuclear fuel. One of the main subsystems of ADS is a high energy (∼1 GeV) and high current (∼30 mA) CW proton Linac. The accelerator for ADS should have high efficiency and reliability and very low beam losses to allow hands-on maintenance. With these criteria, the beam dynamics simulations for a 1 GeV, 30 mA proton Linac has been done. The Linac consists of normal-conducting radio-frequency quadrupole (RFQ), drift tube linac (DTL) and coupled cavity drift tube Linac (CCDTL) structures that accelerate the beam to about 100 MeV followed by superconducting (SC) elliptical cavities, which accelerate the beam from 100 MeV to 1 GeV. The details of the design are presented in this paper.

Preliminary design studies of a 100 MeV H−/H+ LINAC as injector for SNS synchrotron/ADS LINAC

It is proposed to construct a spallation neutron source (SNS) at Centre for Advanced Technology (CAT) based on a 1 GeV proton synchrotron with 100 MeV H− LINAC as injector. Additionally, the LINAC can form the first 100 MeV part of a 1 GeV proton LINAC to be built in future for accelerator driven system (ADS) applications. We are exploring a configuration of the 100 MeV LINAC which will consist of an H− ion source, a 4–6 MeV RFQ followed either by a 20 MeV drift tube LINAC (DTL) and 100 MeV separated function drift tube LINAC (SDTL) or a coupled cavity drift tube LINAC (CCDTL) structure. In this paper, we present the results of our preliminary physics design studies of the RFQ-SDTL, RFQ-CCDTL and RFQ-DTL-SDTL configurations. The design of the 4.5 MeV RFQ is discussed along with the matching sections between the RFQ-SDTL/DTL and RFQ-CCDTL. The choice of the accelerator configuration and that of various parameters of the individual accelerator structures under consideration are discussed. The design objectives are to arrive at a configuration which eases heat removal for CW operation and which is less prone to halo formation in order to reduce the beam loss at higher energies.

Rotating coil measurement system for the APT/LEDA CCDTL quadrupole magnets

A rotating coil measurement system has been developed to characterize the magnetic properties of the Coupled Cavity Drift Tube Linac (CCDTL) quadrupole magnets for the Accelerator Production of Tritium-Low Energy Demonstration Accelerator (APT/LEDA) at the Los Alamos Neutron Science Center (LANSCE). The setup is designed to measure the quadrupole gradient-length product with an absolute error of less than 0.25%, and to determine the relative multipole content of the quadrupole at a radius of 80% of the aperture. The bench for the system consists of a granite surface plate with a pair of rails attached on which the magnet and rotating coil supports rest. The signal is routed through a slipring to a digital voltage integrator triggered by an incremental encoder attached to one end of the coil. Two different rotating coils were designed and fabricated for the system. The first coil is a conventional radially-wound harmonic coil that provides a good measure of the relative quadrupole strength and harmonic content, while the second coil is a specially designed printed circuit coil that can accurately measure the quadrupole gradient-length product.