POLI-new polarised neutrons single crystal diffractometer at the hot source of FRM II
POLI-new polarised neutrons single crystal diffractometer at the hot source of FRM II
The ability to produce intensive neutron beams with energies above 100 meV (called also hot neutrons) for the condensed matter investigations, is a unique feature of the reactor sources. Hot neutrons are very important for the accurate structure determination in the materials where other diffraction...
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Personal Name(s): | Hutanu, Vladimir (Corresponding author) |
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Sazonov, Andrew / Luberstetter / Roth | |
Contributing Institute: |
JARA-FIT; JARA-FIT Streumethoden; JCNS-2 JCNS-FRM-II; JCNS-FRM-II |
Imprint: |
2014
|
Conference: | Deutsche Tagungfür Forschung mit Synchrotronenstrahlung, Neutronen und Ionenstrahlen, Bonn (Germany), 2014-09-21 - 2014-09-23 |
Document Type: |
Poster |
Research Program: |
Jülich Centre for Neutron Research (JCNS) FRM II / MLZ Quantum Condensed Matter: Magnetism, Superconductivity Controlling Collective States |
Subject (ZB): | |
Publikationsportal JuSER |
The ability to produce intensive neutron beams with energies above 100 meV (called also hot neutrons) for the condensed matter investigations, is a unique feature of the reactor sources. Hot neutrons are very important for the accurate structure determination in the materials where other diffraction techniques are less sensitive e.g X rays for the compounds containing light atoms like O, N, H, or e.g. thermal neutrons strongly absorbed by the rear-earth elements. On the other side the study of the hydrogen bonds and magnetic properties of the rear-earth compounds is of the tremendous importance in the actual condensed matter physics both from the fundamental and applied point of view. FRM II reactor in Garching is only one of the very few worldwide which has a secondary source for producing hot neutrons. In the last years the single crystal diffractometer HEiDi operated by RWTH Aachen was only instrument using the beam of the hot source at FRM II. The high user demand for this beam line is reflecting in the fact that HEiDi has the highest overbooking factor (> 3.5) of the all MLZ Instruments. In order to increase the scientific output from this unique facility, the proposal on building a second instrument on the hot source has been accepted. POLI as an abbreviation from Polarisation Investigator is a new versatile single crystal diffractometer at the hot souse of FRM II reactor in Garching, realized by RWTH Aachen University under the “Verbundforschungsprojekt” of BMBF in 2010-2013. Recently, in January 2014, first neutron beam measurements and test scattering experiment have been successfully performed on new POLI beam line. An independent operation of the two diffractometers POLI and HEiDi at the hot source FRM II become possible. POLI is mostly dedicated to the investigation in the field of magnetism, but not only. The separation of the polarization from the neutron optic allowed both polarized and non-polarized neutron diffraction experiments with variable wavelength, from hot to thermal. Two different single crystal polarized neutron diffraction techniques namely spherical neutron polarimetry and flipping-ratio measurements will be used on the new instrument. 3He spin filters are employed as a polarization technique. The concept of the instrument, its design and the applied experimental techniques will be discussed. First results of the test experiment on the new beam line as well those of the spherical neutron polarimetry using last generation polarization analysis device Cryopad will be presented. |