Paul Scherrer Institute

The Paul Scherrer Institute (PSI) is a multi-disciplinary research institute which belongs to the Swiss ETH-Komplex covering also the ETH Zurich and EPFL. It was established in 1988 by merging in 1960 established EIR (Eidgenössisches Institut für Reaktorforschung = Federal Institute for Reactor Research) and in 1968 established SIN (Schweizerisches Institut für Nuklearphysik = Swiss Institute for Nuclear Physics).

The PSI is a multi-disciplinary research centre for natural sciences and technology. In national and international collaboration with universities, other research institutes and industry, PSI is active in solid state physics, materials sciences, elementary particle physics, life sciences, nuclear and non-nuclear energy research, and energy-related ecology.

It is the largest Swiss national research institute with about 1,250 (year 2006) members of staff, and is the only one of its kind in Switzerland.

PSI is a User Laboratory and runs several particle accelerators. The 590MeV cyclotron, with its 72MeV companion pre-accelerator, is one of them. As of 2006, it delivers up to 2mA proton beam, which is the world record for such proton cyclotrons. It drives the spallation neutron source complex. The latest accelerator built (in 2001) is the Swiss Light Source (SLS), a synchrotron light source with a 2.4GeV electron storage ring. It is one of the world's best with respect to electron beam brilliance and stability.

The proton accelerators are also used for the proton therapy program.

Research fields

* Solid-state physics and materials sciences
* Elementary particle physics
* Life sciences and medicine
* Nuclear energy and nuclear safety
* Non-nuclear energy
* Energy-related ecology

Proton accelerators

Injektor-1

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.

pallation Neutron Source (SINQ)

pallation Ultracold Neutron Source (UCN)

wiss Light Source (SLS)

Proton Therapy Program

Since 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 [http://p-therapie.web.psi.ch/e/proscan.html PROSCAN] ) with the objectives to install a dedicated and compact superconducting proton accelerator and to develop a new Gantry ( [http://p-therapie.web.psi.ch/e/forschung.html 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.

ee also

* Proton therapy

External links

* [http://www.psi.ch PSI Homepage]
* [http://p-therapie.web.psi.ch/e/index.html Proton therapy program]
* [http://abe.web.psi.ch/protonen/ High-Intensity-Proton-Accelerators at PSI]