Review of Charged Particle Dynamics. Beam Optics and Focusing Systems Without Space Charge. Linear Beam Optics with Space Charge. Self-Consistent Theory of Beams. Emittance Variation. Beam Physics Research from 1993 to 2007. Appendices. List of Frequently Used Symbols. Bibliography. Index.

Theory and Design of Charged Particle Beams

Production of positron emitting radioactive isotopes /sup 18/F, /sup 15/O, /sup 11/C and /sup 13/N for use in positron emission tomography is important for medical imaging. The present state of the production art is to use cyclotrons to accelerate deuterons to an energy range in the 10's of MeV and impinge the deuterons on appropriate targets. An alternative approach is to use a cascade of RFQ's to accelerate /sup 3/He ions to 10-MeV as the bombarding particles. Due to the lower background radiation, a /sup 3/He accelerator requires far less shielding than a cyclotron, in addition to other advantages. This paper will discuss briefly the end to end ion optics design of an RFQ based /sup 3/He PET accelerator. Emphasis will be on the medium energy beam transport (MEBT) portion. The MEBT required a solution to the difficult problem of matching two RFQ's while allowing room for a gas jet stripper. Our solution to this problem could be modified to allow a match between high power RFQ's and linacs, a problem faced by several possible future accelerators.

Ion optical design of the BRF-FNAL-SAIC-UW PET accelerator

An RFQ linac has been built that accelerates 3He to 105 MeV for production of C, N, O, F isotopes for PET The accelerator produces 70 μs pulses, at 360 Hz, a 25% duty cycle, with a peak current of ∼6 mAe The RFQ delivers ∼100 μAe A recirculating water target has been evaluated for production of 18F and low specific activity 15O Recoil chemistry within the target has been evaluated to improve 15O specific activity Gas targets have also been tested for production of 15O 13N is made from carbon Several target materials have been evaluated for producing 11C, including C, B and Be The challenges of targetry for this high current, low energy machine led us to evaluate large, high aspect ratio windows and grid supports The 3He RFQ is a useful research machine for testing targets for pulsed, high power density, low LET beams

Production of PET radionuclides using a 10.5 MeV {sup 3}He RFQ accelerator

A cellular electron‐cooled storage ring system for achieving particle‐beam fusion‐based‐energy is described. The system uses multiple electron‐cooled, overlapping storage rings to enable colliding‐beam fusion. Particles are continuously fed into the storage rings, and the electron cooling systems continuously correct the ion beam trajectories, compensating for various scattering events that occur in the system. This allows for large currents to be built up in the ion storage rings. The rate of fusion reactions that occur in the overlap regions between the storage rings can be increased by focusing to enable power outputs of interest for fusion‐based power reactors. The system can be built with technology readily available today.

Ecofusion: an electron‐cooled, cellular approach to harnessing fusion power

Beam emittance measurements have been performed on the {sup 3}He{sup +} beam at the PET isotope production accelerator, being commissioned at Fermilab for the Biomedical Research Foundation in Shreveport, Louisiana, USA. Emittances have been measured at injection to and extraction from the first RFQ, at 20 keV and 1 MeV, respectively. A single slit followed by a 48 electrode collector is used in the standard way to measure the divergence of the {sup 3}He{sup +} beam as a function of position. Noise reduction operations have been developed, both in hardware and software. These techniques and the emittance measurement results are presented.

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Emittance measurement techniques used in the 1 MeV RFQ for the PET isotope linac at Fermilab

The /sup 3/He RFQ linac for production of positron-emitting radioactive isotopes accelerates singly-ionized /sup 3/He/sup +/ ions to an energy of 1 MeV in a 212.5-MHz RFQ. The ions are then stripped to form doubly-ionized /sup 3/He/sup ++/ in a gas-jet stripping cell, and transported by the MEBT to the 425-MHz RFQ string for acceleration to 10.5 MeV. The stripper cell utilizes a mechanical injector to provide gas pulses to a nozzle. The directed gas jet passes across the beam into a scavenge section which pumps away the gas. The MEBT is an achromatic, isochronous transport section based on two 270-degree bend magnets. It provides bunched and focused beam to the 425-MHz RFQ string.

Charge stripper and MEBT for the /sup 3/He RFQ accelerator

In 1995, Fermilab and SAIC formed a collaboration with partners from the University of Washington (UW) and the Biomedical Research Foundation of Northwest Louisiana (BRF) to explore an innovative approach to the production of radioisotopes. The accelerator system that is being developed accelerates 3He to 10.5 MeV and then delivers this beam to the target to produce the short lived radioisotopes of interest to the PET community (18F, 15O, 13N, 11C). Research is being conducted to investigate the contribution that this promising approach can make to clinical and research PET. The accelerator system has several very interesting aspects. These innovations include multiple RFQ accelerators configured in series, a gas stripper jet to doubly charge the low energy (1 MeV) 3He beam, and an isochronous matching section to manipulate the transverse and maintain the longitudinal profile of the beam (without the use of an RF buncher) in the charge doubler transition section between RFQ’s. This paper updates the progress of the PET 3He RFQ accelerator, the current status of the design, and some of the interesting ongoing research.

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K. Anderson

Papers

Charge stripper and MEBT for the /sup 3/He RFQ accelerator

Progress Update on the Development of the $^{3}$He Linac for PET Isotope Production