FlatCone - FlatCone

Description

The TAS spectrometers offer a standard for quantitative measurements, allowing detailed observations, but only measure one excitation at a time. The modern trend is to simultaneously collect as many data points as possible. This makes it possible to map substantial regions of the reciprocal space without increasing the measuring time.

FlatCone is typical of this new approach. This TAS option combines a set of analyzers and detectors in a very compact design. It can be installed on the ILL TAS instruments IN8, IN14 and IN20.

Applications

Determination of magnetic structures (high field, high pressure, low temperature) :
study of magnetic phase diagrams (field-temperature, pressure-temperature, or both); 
determination of magnetisation density maps (with the polarised neutron option).

Mainly in condensed matter physics: strongly correlated electron systems (heavy fermion systems, borocarbides compounds, low dimensional magnetic systems, charge/orbital ordering systems) ; molecular magnetism.

Instrument layout

This view from above shows the two sets of 31 analysers.

A general view

FlatCone is shown here installed on IN20 and set in the horizontal plane. The sample is inside a cryomagnet.

A typical diagram

Opposite, a typical signal from lattice excitations collected with FlatCone.
Here in the relaxor ferroelectric PZN-8%PT at an energy transfer of 3 meV measured on IN20 (kf = 3 Å^-1).