JLAB, Newport News, Virginia
Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
The conceptual design of a ring-ring electron-ion collider based on CEBAF has been continuously optimized to cover a wide center-of-mass energy region and to achieve high luminosity and polarization to support next generation nuclear science programs. Here, we summarize the recent design improvements and R&D progress on interaction region optics with chromatic aberration compensation, matching and tracking of electron polarization in the Figure-8 ring, beam-beam simulations and ion beam cooling studies.
TRIUMF, Vancouver
DAE/VECC, Calcutta
TRIUMF (Canada) and VECC (India) are planning to each build a 1.3GHz 50MeV/500kW superconducting electron linac as a driver for producing radioactive ion beams through photo-fission. The two institutes have launched a collaboration with the initial goal to design, build and test a 5-10MeV superconducting injector cryomodule capable of accelerating up to 10mA. A testing area is being set-up at TRIUMF to house the electron gun, rf buncher, injector cryomodule, diagnostic station and beam-dump for beam studies. The project will test all critical elements of the final linac; beam halo generation, HOM excitation, LLRF and rf beam loading and cavity and cryomodule design/performance. The scope and status of the project will be described.
TRIUMF, Vancouver
The medical isotope Molybdenum-99 is presently used for 80-85% of all nuclear medicine procedures and is produced by irradiating highly enriched uranium U-235 targets in nuclear reactors. It has been proposed* that an electron linac be used for the production of 99Mo via photo-fission of a natural uranium target. The nominal linac parameters are 50 MeV electron energy, 100 mA beam current and 100% duty factor. This paper describes two possible superconducting RF accelerator design concepts based on the frequencies of 704 MHz and 1.3 GHz. We present design parameters, efficiency and reliability estimates, and comparisons between the two options. Finally, we describe how the proposed e-linac project at TRIUMF can be used for proof-of-principle demonstration and critical validation tests of the accelerator-based production of 99Mo.
*Making Medical Isotopes: Report of the Task Force on Alternatives for
Medical-Isotope Production (2008)
TRIUMF, Vancouver
JLAB, Newport News, Virginia
The medical isotope Molybdenum-99 is presently used for 80-85% of all nuclear medicine procedures and is produced by irradiating highly enriched uranium U-235 targets in NRU reactors. It was recently proposed that an electron linac be used for the production of 99Mo via photo-fission of a natural uranium target coming from the excitation of the giant dipole resonance around 15 MeV. The photons can be produced using the braking radiation (“bremsstrahlung”) spectrum of an electron beam impinged on a high Z material. In this paper we present an alternate concept for the production of 99Mo which is also based on photo-fission of U-238, but where the ~15 MeV gamma-rays are produced by Compton backscattering of laser photons from relativistic electrons. We assume a laser wavelength of 330 nm, resulting in 485 MeV electron beam energy, and 10 mA of average current. Because the induced energy spread on the electron beam is a few percent, one may recover most of the electron beam energy, which substantially increases the efficiency of the system. The accelerator concept, based on a three-pass recirculation system with energy recovery, is described and efficiency estimates are presented.
TRIUMF, Vancouver
DAE/VECC, Calcutta
A 0.5 megawatt electron linear accelerator is being designed at TRIUMF in support of its expanding rare isotope program, which targets nuclear structure and astrophysics studies as well as material science. The first stage of the project, a 25 MeV, 5 mA, cw linac matching the isotope production target power-handling capability in the next five-year plan, is planned to be completed in 2013. The injector cryomodule development, which is being fast tracked, is the subject of a scientific collaboration between TRIUMF and the VECC laboratory in Kolkata, India. The paper gives an overview of the accelerator design progress.
TRIUMF, Vancouver
The ISAC facility, located at TRIUMF, first began delivering radioactive ion beams (RIBs) in 1998, added post-accelerated beam capability in 2001, and is regarded as one of the premiere RIB facilities in the world. The existing constraints on RIBs of Z<83 and accelerated beams of A/q<30 with energies limited to 5MeV/u are being addressed. A charge-state booster for RIBs has been commissioned to alleviate the A/q<30 restriction and has successfully delivered multi-charge beams through the ISAC accelerators. The 5MeV/u license limit will be removed once an on-line beam monitor is commissioned, allowing beams of up to 11MeV/u to be delivered presently, and increased to over 20MeV/u when the next accelerator phase is installed. In 2008, an actinide target was used to produce RIBs of Z>82; this successful test was performed on a uranium target with yields measured and radiation safety monitored. A new Beam Delivery group has been formed to integrate all aspects of RIB production, which has led to improved efficiency and greater experimental results. These new capabilities will be presented, showing how 2009 promises to be both an exciting and productive year at ISAC.