Research fields
Proton acceleratorsInjektor-1
Injector 1 is a variable energy cyclotron built by the Dutch company Philips Gloeilampen-Fabrieken. Its one-piece magnet has an azimuthally varying magnetic field for vertical focusing even at relativistic energies. The beam energy goes up to 72 MeV for protons and 120 MeV Z2/A for ions with charge Z and mass number A. Equipped with several ion sources, Injector 1 offers a wide variety of beams ranging from protons and deuterons to light and heavy ions. Polarized beams of protons and deuterons are also available. In 1994 an ECR ion source was installed to extend its ability to accelerate heavy ions. At present (2004) it is used mainly for low-energy experiments, OPTIS eye tumor therapy, and for the EURISOL / LiSoR experiment in the scope of the Megapie project. Injektor-2
The Injector 2 cyclotron has been built to replace the multiparticle variable energy Injector 1. It provides high intensity, high quality beams of 72 MeV protons to be injected into the 590 MeV Ring cyclotron. The Injector 2 is itself a ring cyclotron, but with 4 sectormagnets and with an extremely low injection energy of 870 keV. The 870 keV proton beam is achieved by extracting protons from an ion source with 60 kV and additional acceleration of the particles by means of a Cockcroft-Walton type accelerator operated at 810 kV. It was put in operation in 1984. Ring
The Ring Cyclotron is a separated sector cyclotron with a fixed beam energy of 590 MeV, built by PSI and commissioned in 1974. The 72 MeV beam from either one of two injector cyclotron enters from the back of the cyclotron, is injected into an orbit in the center of the Ring, accelerated over about 220 revolutions and extracted at the full energy. The design is based on criteria that allow operation at very high beam intensities: an open structure of four large and powerful RF-cavities providing a high acceleration voltage, and a flat-top cavity operating at the third harmonic of the accelerating RF-voltage. The resulting strong, phase-independent energy gain per revolution gives good turn separation and hence beam extraction with low beam losses. This is a mandatory condition for high current operation in a cyclotron. Spallation Neutron Source (SINQ)
Spallation Ultracold Neutron Source (UCN)
Swiss Light Source (SLS)Proton Therapy ProgramSince 1984 PSI operates the OPTIS facility for treatment of eye tumours. It was the first such installation in Western Europe, developed by PSI physisists. In close cooperation with the 'Hôpital Opthalmique' of the University of Lausanne by March 2008 nearly 5000 patients have been treated at PSI with this unique method, in which a proton beam is directed accurately onto the eye tumour. Since 1996 PSI operates also the first and only compact scanning-Gantry worldwide for proton radiation therapy of deep-seated tumours. The spot-scanning technique developed at PSI enables malignant tumours to be targeted with high precision deep inside in the body, and their growth successfully stopped, without damaging healthy tissue around the target area. By March 2008 320 patients have been treated at the Gantry 1, suffering from brain, head and neck, skull-base, spinal cord or abdominal tumours. The excellent and promising results of patient treatment have led to the (Project PROSCAN) with the objectives to install a dedicated and compact superconducting proton accelerator and to develop a new Gantry (Gantry 2) with advanced 2-dimensional and fast parallel scanning features. The new compact superconducting cyclotron is in operation since February 2007. The Gantry 2 is under construction and first beam to the isocenter ist planned for May 2008. Patient treatment at Gantry 2 will start first half of 2009. The goals of these developments are to increase radiation precision of even moving tumours and to transfer the knowledge and proton therapy technology into hospital-based projects. With the expansion of the facility, PSI will be able to strengthen the clinical research program and to treat more than 500 patients per year, including those with eye tumours. See also
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