The Oslo Cyclotron Laboratory (OCL) is jointly operated by the Departments of Physics and Chemistry of the University of Oslo (UiO). It is the key facility for the interdisciplinary Center for Accelerator based research and Energy Physics (SAFE) at UiO. The main research activities at OCL include Fundamental Nuclear Physics, fundamental Nuclear Chemistry, Applied Nuclear Chemistry for medical research (PET), and Applied Nuclear Physics for energy applications and radiation hardness tests. The staff includes four professors in Nuclear Physics, two in Nuclear Chemistry, and one in PET research; in addition to a varying number of postdocs, PhD., and master students. The staff includes furthermore, two professors from the Norwegian Institute for Energy Technology (IFE) in Kjeller and Halden, respectively, with part-time appointments at UiO.
The Oslo Cyclotron Laboratory is operated by three engineers. The accelerator at OCL is a MC35 Scanditronix cyclotron built in 1979. It delivers beams of protons and deuterium of currents up to 50 μA and energies from 2 up to 35 MeV (for protons), as well as He-3 and He-4 beams of up to 15 MeV and intensities of 3 and 15 μA respectively.
The accelerated beams are distributed to 5 target stations, two of which are located inside the cyclotron vault and can receive high currents for radioactive isotope production and nuclear chemistry experiments. The other three are located in the experimental hall. The target station most relevant for ERINDA is equipped with the CACTUS detector array consisting of 28 large volume NaI detectors and the SiRi particle detector array. Another target station is currently equipped with a large volume scattering chamber and the third one is used for radiation hardness tests of electronic components.
Relevant experience
This group has participated in the ERINDA project of the EURATOM Framework program. At the Oslo Cyclotron there is a program to study level densities and gamma strength functions. These are fundamental properties and important inputs in cross section calculations. During the last two years the program has been extended to the actinide region and the detector setup allows at the same relative cross section measurements using the surrogate method. CHANDA collaboration members are already involved in these type of experiments, namely Orsay, Bordeaux and Saclay.
The Oslo Cyclotron is the ideal place to perform capture surrogate experiments on actinides. The experimental combination of the Cactus NaI array and the SiRi position-sensitive telescope allows us to improve our efficiency by a factor of around 30 compared to previous experiments and thus this is an indispensable apparatus for these type of studies. At the Oslo Cyclotron there are also no problems obtaining beam time for either experiments or equipment/target tests. Therefore, the time from conception to realization of an experiment can be extremely rapid, and we can make significant progress in an amount of time frame that is inconceivable elsewhere. Note also that the same experiments can be used to determine level densities using the technique developed at Oslo. The two measurements (surrogate and level densities) are performed simultaneously. The level density information is useful for both applied and fundamental reasons, since cross section calculations rely heavily on level density models which may not accurately describe reality.
As Norway is not member of the EU. The University of Oslo provides the access to its facilities within CHANDA without financial compensation from the EU.
Scientific and technical personnel involved
Tree permanent physicists: A. Görgen, M. Guttormsenand and S. Siem; and one permanent nuclear chemist: J. P. Omtvedt; will be involved in the project. All of them have a large experience in nuclear spectroscopy and nuclear reactions. In addition, the 3 engineers at the Cyclotron will contribute by providing technical assistance and excellent beam conditions.