Department of Physics annual report 2000 - Fysiikan laitos - Helsinki.fi

Professor Lennart Simons in front of
the analysing magnet of the Van de
Graaff accelerator in the new laboratory
building erected for the accelerator
at Siltavuori.
effective. All the research groups worked busily in
the new research fields that opened up for Finnish
nuclear physicists and the number of academic
dissertations grew constantly. Also more equipment
was obtained. Juhani Kantele (later professor of
physics at the University of Jyväskylä) had a neutron
generator for 14 MeV neutrons installed in
1964 in the Siltavuori rock below the accelerator
laboratory. With this device decays of short-lived
isotopes were studied, yielding information on the
nuclear structure. An isotope separator was installed
in 1964, first producing separated targets
for research with the VdG accelerator, later being
used in materials and applied physics experiments.
In 1968 the Department of Physics was divided
into two divisions: the General division and the
Accelerator laboratory. Now the Accelerator laboratory
was expanded and consisted of the VdG
laboratory, the isotope separator laboratory, the
neutron generator laboratory, and the laboratory of
Raman spectroscopy led later by professor Stenman
(associate professor 1973-). The first head of
the Accelerator laboratory was Professor Lennart
Simons. Simons was appointed to the Swedish
language chair in physics in 1941 (professor 1941-
72). His principal achievements were in the area of
nuclear physics.
The accelerator laboratory expanded in 1982
when the new laboratory building was built in
Kumpula, on the future campus of the Faculty of
Science. The new premises were needed for a new
accelerator, the 5 MV tandem accelerator EGP-10-
II. The research program of the Accelerator laboratory
shifted strongly to the area of materials and
applied physics. The research work continued in
the old laboratory at the VdG accelerator. The
isotope separator was moved to the new accelerator
laboratory in Kumpula. The neutron generator had
been taken out of use ten years earlier. When the
Department moves in 2001 to the new departmental
building in Kumpula, Physicum, the VdG will
be broken up. The high voltage terminal, the ion
source, and the accelerator tube will be moved to
the national museum of technology. Some parts,
such as some target stations, will be reinstalled in
Kumpula. During the decade 1984-94 the laboratory
was led by Juhani Keinonen (associate professor
1982-94 and professor of applied physics 1994-).
The history of the 2.5 MV VdG accelerator is
the history of the Finnish nuclear physics and the
laboratory is the pioneer also in the accelerator
based materials physics. The VdG accelerator is
the most important single equipment in the history
of physics in Finland. During 40 years over one
thousand scientific articles in international journals
have been published by the researchers of the
accelerator laboratory, half of them on the basis of
the research at VdG. Over 60 PhD theses have been
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