The Department of Physics has wide collaboration with many foreign universities and research centres, 94 European institutes in addition to the 50 domestic ones, 40 institutes in North and two in South America, and 13 in Asia. As collaborative institutes are considered only those when a joint peer reviewed publication has been done. The CERN collaborations with large research groups are excluded. Distribution of collaboration laboratories in different continents (excluding domestic ones and CERN collaborations with large research groups).

Ten foreign scientific visitors worked in the Department for longer than one month (total 18 months), 18 visitors over two weeks (total 10 months) and 44 persons paid a shorter visit. Seventeen staff members visited foreign research centres for periods longer than one month (altogether 126 months, six people for the whole year) and 18 members for at least or over two weeks (total 15 months). A list of the visitors and visits is given in the supplement part of the Annual Report.

The number of scientists paying a visit longer than two weeks but shorter than a month in the Department has been quite constant in 1994-96, varying between 16 and 18 (total length 10-15 months) and to foreign centres 15-18, total length of stay rising from 6 to 15 months in the period 1994-96.

The research groups of the Department are also in co-operation with tens of university departments in Finland and several Finnish research institutes in both physics and interdisciplinary research. The collaborating universities and departments are the following ones: University of Helsinki, about 15 departments in three faculties, Helsinki University of Technology eight laboratories, Technical Research Centre of Finland ten departments, University of Jyväskylä, University of Kuopio, Tampere University of Technology, University of Turku, Åbo Akademi, and about 15 other state or research institutes.

Collaboration with the newly founded Helsinki Institute of Physics (HIP) is being developed both in research and post-graduate education.