Facts and figures


PSI's federal contribution of 2016 amounted to CHF 321.8 million. Revenues for research and teaching divided up as follows (in millions of Swiss Francs):
  Mio. CHF %
Revenue for research, teaching & operation of the large research facilities
from federal contribution 298.8 68.3 %
Tuition fees and other utilisation fees 1.4 0.3 %
Research contributions, mandates and scientific services
– Industry-oriented research 29.5 6.7 %
– from SNSF, CTI and Special federal funding of applied research 39.9 9.1 %
– EU Framework Programmes for Research and Innovation 12.8 2.9 %
– Other project-oriented third-party funding 18.2 4.2 %
Donations and bequests 0.5 0.1 %
Other revenue 36.6 8.4 %
Operating revenue 437.7 100.0 %
Keyfigures for expenses and investments
Personnel expenses* 243.8  
Other operating expenses** 87.3  
Investment in tangible fixed assets* 70.5  
For more financial information, please refer to our Annual Report.

* including SwissFEL
** without contribution to accommodation


PSI had roughly 2100 employees at the end of 2016. One quarter of this figure was accounted for by postdoctoral students, doctoral students and undergraduates. A total of 38% of the positions are held by scientists. 48.5% of the positions were occupied by technicians and engineers. With their varied competencies, they ensure that the Institute’s existing scientific facilities always work reliably and that new ones are built according to plan. They thus make a major contribution to the Institute’s scientific achievements. 8% of the positions were held by administrative staff. 27% of the employees are women, while 48% are non-Swiss citizens.

Teaching and postgraduate support

In 2016, more than 320 postgraduate students were working on their doctoral research projects at PSI. More than 200 were employed on a regular basis by PSI. Most of these young researchers had previously undertaken undergraduate studies in physics, chemistry or engineering, mainly at ETH in Zurich or EPFL Lausanne, at the Universities of Zurich or Bern, or in other countries. However, PSI's researchers were not just engaged in the further education of students on-site at Villigen. More than 100 PSI scientists hold a lecturing post at a Swiss university or technical university. This involvement at universities is mostly unpaid, thus generating a double benefit for the universities, as they can offer their students access to state-of-the-art research at large facilities not available at any university. At the same time, the universities are also able to provide their teaching at a lower cost.

User laboratory and international network

PSI makes significant contributions as a national user laboratory to researchers from both the universities and industry. About two thirds of the total budget go towards the operation, maintenance and ongoing development of the large research facilities, as well as the supervision and support of researchers from Swiss universities. The Institute supports annually more than 2500 scientists at its large facilities.

The success of a user facility is reflected in the interest of the scientific community in performing experiments at that facility and in the number of publications generated which are based on experiments carried out at it.

In 2016, around 900 articles based on experiments at PSI's large research facilities are published in scientific journals. More than 5000 visits to PSI per year take place of scientists from around the world who come to perform experiments at one of the facilities. Most users of neutrons or synchrotron light come to PSI from Switzerland or member countries of the European Union. The Swiss scientists are evenly distributed between PSI itself and other centres. Most of the external researchers come from ETH Zurich, but regularly scientists come from EPF Lausanne, the Swiss universities and the Swiss Federal Laboratories for Materials Testing and Research, Empa. In the case of muon experiments, an extraordinarily high percentage of users come from overseas. One reason for this is certainly the fact that PSI is the only institute in the world operating a facility for experiments with slow muons.
Statistics for the year 2016
PSI Facility Swiss Light Source SLS Spallation Neutron Source SINQ Swiss Muon Source SμS Laboratory for Particle Physics LTP Total 2016
Number of user visits 3134 391 275 663 4463
Number of experiments 1037 189 225 5 1456

Proton therapy – immediate benefit for the society

Some sections of society benefit directly and immediately from out-patient proton therapy at the Institute. In 2016, over 5800 fractions were delivered to cancer patients and the center for proton therapy at PSI registered almost 1900 clinical consultations. A success rate of more than 98% puts PSI at the very forefront internationally in regard to the successful irradiation of melanoma of the eye. In 2016, almost one third of the patients with non-ocular tumours were children and teenagers. About 58% of whom were infants, who received their treatment under anaesthesia. Two irradiation units (Gantry 1 and Gantry 2) for non-ocular tumors and one unit (OPTIS2) for ocular tumors are ready for patient treatment. With a grant from the Cantons of Aargau and Zurich, proton therapy can be further expanded and research can be intensified. A third Gantry is currently under construction. This development will offer a greater number of Swiss cancer patients the opportunity to benefit from this innovative treatment in the future.