Presentation
Group of Operation and Exploitation of RPI
The main goal of the Group of Operation and Exploitation of RPI (OERPI) is to be able to satisfy the users' needs (dosimetry, radiological protection and neutronic calculations) while conducting all activities with the assurance that the reactor is operated in a safe and reliable manned by a highly competent and motivated staff. The activities of the group members are complemented by their active participation in the installation and operation of new experimental devices (fast and epithermal neutron beam, emission channeling etc.).
The implementation of such objectives demands a variety of projects, some of which are repetitive in objective and variable in content, while others address specific aspects of the same end situation.
1. Main Activities
Main activity areas are the following:
- Testing of electronic circuits for the LHC at CERN: Temperature measurement is a key issue in the LHC facility at CERN, as it will be used to regulate the cooling of the superconductor magnets. The signal conditioners for cryogenic thermometry are expected to receive a fast neutron fluence of the order of 2×1013 n/cm2 during a 10 year period, as well as a gamma dose of 500 Gy, and this can affect the operation of the commercial circuits used in their construction. The operating conditions of these circuits are simulated using a fast neutron irradiation facility built in 2000.
- Mixed field dosimetry: The dosimetry of gamma radiation in mixed fields (photons+neutrons), as found in nuclear reactors, has several special features. Therefore, the application of the methods used in pure gamma radiation fields is not straightforward. Experiments aiming at the study of dose-effects, respectively, in electronic circuits and in biological samples are performed at RPI. The use of thermoluminescent dosimetry (TLD) is, due to its strong advantages compared to standard methods, the main concern of the studies performed.
- Emission channeling using neutron induced reactions: A setup for the investigation of the lattice of single crystals as well as intrinsic and extrinsic defects by emission channeling/blocking of charged particles (protons, tritons, alphas) from thermal neutron induced reactions at the Portuguese Research Reactor (RPI) facility has been designed. The method will enable high sensitivity studies of crystalline materials containing light elements like Li, B and N which are difficult to study by means of conventional ion beam techniques.
- Monte Carlo simulation for neutron and photon fields: Monte Carlo simulation is a highly appropriate tool for describing the transport of neutron and photons. Besides the local applications in the characterization of radiation fields at the RPI, the collaboration in two large international projects gave a boost to this field: 1) the n-TOF project at CERN that aims at the determination of neutron cross sections in the energy range from 1 eV to 250 MeV with high accuracy and 2) the PDS-ADX project concerned with the design of accelerator driven subcritical system for future nuclear energy production.
- SIMPLE-Lx: a Portuguese contribution to the SIMPLE dark matter search: SIMPLE is a search, based on a room temperature freon superheated droplet detector (SDD), for evidence of spin-dependent weakly-interacting massive particles (WIMPs). SIMPLE-Lx is a local spin-off, designed to provide monochromatic neutron calibrations of the SIMPLE SDD, and initiate a transfer of SDD fabrication technology to ITN. A Laboratory to produce SDD’s is under construction. The collaboration envisages investigating the chemistry of the SDD’s to be able to initiate new module design based on CF3Br or CI3F, with a capacity to explore spin-independent couplings. Very important spin-offs in Neutron Dosimetry and Spectroscopy will be pursued.
Core pool.
2. Equipment and Devices
Main equipment and infrastructures are the following:
- 1 MW open core pool-type reactor with various irradiation devices in the core
- External irradiation setups for thermal, epithermal and fast neutron irradiations
- Emission channeling setup (under construction)
- Hot cells and hot chemistry laboratory
- Laboratory for thermolumiscence dosimetry
- Laboratory for SDD detectors fabrication (under construction)
Legends: Control Room on 1st floor.
3. Technical Services
The research reactor is available to users five days a week, from 09h00 to 24h00, and provides:
- Support to setup the experiments;
- Characterization of radiation fields in the experimental areas;
- Irradiations of samples in various irradiation devices;
- Production of radioisotopes;
- Detailed information on the irradiation conditions is available on request from URNS.
Potential users are requested to contact URNS giving details on the intended experiments / irradiations.
Other Services
- Visit each research activity group indicated above for specialized offers.