IFF

 ZFR

 ZEL

 ZAT

In charge: Prof. T. Brückel, IFF, t.brueckel@fz-juelich.de

Aims and Objectives

The macroscopic properties of condensed matter result from an interplay of its electronic, atomic and molecular components. Scattering methods and spectroscopy with neutron and synchrotron radiation provide a basis for our present day understanding of condensed matter on a submicroscopic level. The operation of large facilities, such as the research reactor FRJ-2 and the corresponding instruments, is a central task of the Helmholtz-centers. The research and development project M05 comprises:

• the operation and the further development of the research reactor FRJ-2 as the most powerful neutron source within the HGF, mainly for spectroscopy and scattering experiments from condensed matter;
• the development and the construction of novel scattering instruments for operation at the research reactor FRJ-2, but also at other neutron and synchrotron sources, as well as the improvement of these instruments;
• the operation of these instruments, in particular for the use by guest groups from universities, research centers and industry.

Significant Results in 2003

Operation of the Reactor: In the year 2003, the reactor has been in operation at nominal power during 10 cycles corresponding to 195 days. Availability above 95 % was achieved, also for the cold source and the irradiation facilities.

Further Development of the Reactor: The Monte Carlo programme MCNP, which simulates the nuclear physical processes in the reactor core, has been verified and is accepted by the safety authority. The FRJ-2 has been refurbished in several areas, such as the control system of the cold source, the radioprotection instrumentation and the control system of the reactor protection system. The conversion of the reactor core from HEU to LEU has further progressed: the development of a new type of fuel element is completed, the detailed safety report has been written. In January 2003, the conversion to low enriched Uranium has been applied for at the safety authority. The license to operate with LEU is expected in the beginning of 2004.

Production of Radioisotopes for Medical Applications: The FRJ-2 is one of the four research reactors in Europe, in which 99Mo is produced as a preproduct of the radiopharmacum 99Tc. In 2003, we could irradiate for the first time uranium targets simultaneously in three irradiation rigs after installation of the third irradiation insert.

Operation of the Neutron Scattering Instruments at the FRJ-2: In 2003, 15 neutron scattering experiments were in full user operation at the FRJ-2. 154 experiments were performed. 92 of these experiments, corresponding to a portion of 60 %, were done by external groups. The demand by European users in the framework of the "Access to Research Infrastructure" programme of the European Union remains high with overload factors between 2 and 3. The external usage is as follows: 43 % of the experiments are done by German groups, 39 % by groups from other EU-countries and 17 % by groups from outside Europe.

Construction and Further Development of Instruments at the FRJ-2: The systems for instrument control and data acquisition are converted to the new "Jülich-Munich-Standard" at all neutron scattering instruments of the FRJ-2. This standard has been defined together with the instrumentation group of the FRM-II. For the instruments SV-29, HADAS, KWS-1 and KWS-3, the new standard has already been implemented. Work is in progress for the instruments SV-30, KWS-2 and DNS. The small angle scattering instrument KWS-1 has received a new fast scintillation detector. Work is ongoing for a detector for the instrument KWS-2.
The most important methodological breakthrough is the invention of a new method for vectorial polarisation analysis, which has been implemented at the instrument DNS. The method is based on a precession of the neutron polarisation in the guidefield. It allows for the first time the vectorial polarisation analysis simultaneously for all angles and energy transfers.

Method Development for Instruments at Other Sources: To build a beyond state of the art NSE spectrometer at the upcoming MW spallation neutron source, SNS is the major challenge of our recent research and development programme. The layout of a new NSE spectrometer with worldwide unique features i.e. highest energy resolution with spin-echo times above 1 microsecond and a dynamic range of more than six decades has been completed. The concept has been presented in spring 2003 to the Experimental Facilities Advisory Committee of the SNS. It was highly appreciated and it was decided to reserve a beamline (BL 15) for the proposed NSE instrument. Detailed design work has been started.
Construction of all components for the backscattering spectrometer at the FRM-II is essentially finished. The instrument will be transferred to Garching in 2004. It features a new Doppler drive with a linear motor on airpads and a phase-space transformer and will become the worlds' most modern backscattering spectrometer.

Operation of Instruments at External Sources: Besides the instruments at the FRJ-2 reactor, the following instruments at external sources were operated by FZJ (partially with partners) for use by the broad scientific community: three-axis spectrometer IN12 and spin-echo spectrometer IN15 at ILL in Grenoble; small-angle camera JUSIFA and wiggler beam W1 at HASYLAB in Hamburg; a beamline at the storage ring of BESSY in Berlin and one at DELTA in Dortmund as well as the undulator beamline in the MUCAT sector at the APS in Argonne, USA. In addition, a backscattering spectrometer for the research reactor FRM-II in Munich is being constructed, financially supported by the BMBF.