LiNSTAR™ - Synchrotron Injector Linac Systems

      Several AccSys LINSTAR™ systems are currently in use as injector linacs at a number of proton synchrotron facilities for cancer therapy and physics research. These compact systems can be configured to accelerate either H⁺ or H^- beams, including polarized beams. Stable operation has been shown for a wide range of beam currents, pulse widths and repetition rates. One recently delivered system features beam pulses available on demand at repetition rates as low as 0.1 Hz. Standard LINSTAR™ systems are available at output beam energies from 2 to 7 MeV. Higher injection energies are available as custom linac systems.

      The LINSTAR™ series of proton linac systems are designed to provide moderate-energy proton beams (typically from 2 to 7 MeV) for  injection into high energy proton synchrotrons that are used for proton beam cancer therapy or physics research. These fully integrated systems typically consist of a carefully designed and selected combination of a radiofrequency quadrupole (RFQ) linac, a drift tube linac (DTL) for injection energies of >3 MeV, AccSys' standard rf power system, a high energy beam transport system tailored to the specific requirements of the facility and an optional debuncher cavity. They can accelerate either H⁺ or H^- ion beams and are also available for polarized H⁺ or H^- beams. Standard LINSTAR™ units can provide pulsed beam currents up to 25 mA at pulse widths from 3 to 300 µsec. Operation at pulse repetition rates from 0.1 to 30 pulses per second have been demonstrated, including on-demand pulsing for breath-mode synchronization in proton cancer therapy.


Prototype LiNSTAR™ system (rf power & injector electronics not shown).

LINSTAR™ systems are currently in use at several facilities around the world: 

• A Model PL-2i has been operating at Loma Linda University Medical Center since 1990 as the injector to the high energy proton synchrotron cancer treatment facility. The synchrotron system operates 24 hours a day, 6 days a week and has been described in a number of technical publications. Complete proton therapy systems based on the Loma Linda installation are commercially available from Optivus Technology, Inc.
• Two systems are now in operation in Japan: a Model PL-3i is the injector to the proton synchrotron cancer treatment facility at the Shizouka Cancer Center, which was built by Mitsubishi Electric Company, and a Model PL-7i is the injector for the proton synchrotron cancer treatment facility installed by Hitachi, Ltd. at the Tsukuba Medical Center.
• A Model PL-7i was operated at the Indiana University Cyclotron Facility from 1997 to 2002 as the injector for the CIS compact synchrotron which is in turn the injector for the high energy physics cooler ring. This physics system was decommissioned. The injector for their cyclotron was converted from doing physics research to proton cancer therapy and the Model PL-7i linac is being upgraded for use as a neutron source for research. However, a Model PL-1 RFQ linac is now in operation at the facility.