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Panda

Hi and welcome on PANDA! We hope that you will like our instrument.

PANDA team - Astrid, Igor, Chris, Alistair, Mario, Michal, Anton, Nikolaos and Sebastian


News

Publications

Panda publications represent results on magnetic exciations and phonons in

  • strongly correlated systems
  • frustrated systems
  • superconductors
  • other model materials
  • multiferroic materials

and on hybridization effects of phonons and magnetic exciationa.

See also PANDA at Google scholar!

Show Publications section

Newcomer guide

Are you new to PANDA? You should read our short introduction guide, where you will learn:

  • about our accessible energy-moment space
  • about our resolution limits
  • how to write a proposal
  • how to prepare sample and sample holder

Learn more about PANDA

Sample Environment

Reaching low temperatures, high magnetic field and high pressures brings serious limitation for sample size and signal/noise ratio. If you consider application of special sample environment (everything below 3 K and/or with magnetic field), you should read about our limitations.

  • dimensions of the cryostats
  • usual cooling times
  • restrictions in movement and reachable Q/E space
  • remarks about available high field magnets

Show Sample Environment section

Simulations

If you want to learn details about PANDA, the best is to use our prepared configuration files for neutron raytracing programs.

  • McStas code
  • Simres code

more in simulations section

Data analysis

After the experiment, you usually obtain only a few kB of well formated ASCII data produced by our instrument control software NICOS.

  • Matlab macro to read datafiles with metadata
  • Python macro to read datafiles with metadata
  • UFit suite to do advanced data analysis and evaluation
  • TAKIN for resolution calculation and fitting

data analysis section

Former members

Here you can find the former members of the team and where to find them now:

Typical inelastic (TAS) neutron experiment

Before coming to the instrument:

Know your system's lattice parameters and angles, and it's symmetry. Decide about the sample orientation - you get only one plane

Create hkl-intensity-list (reflection list). –> info about forbidden reflections and the (relative) intensities of the allowed. - Have it available for starting the experiment.

Mark the crystal direction on the sample holder

Mount the sample properly. Think about covering the glue or holder and about either fixing the sample by Al wire or mounting an Al foil bag around.

Mark the crystal direction outside on the cryostat

For magnets, sample mounting needs to be better than within 1°. Depending on the instrument, care that one crystal direction is parallel to the goniometer axis.

Start experiment. Experiment name, sample name, give sample metadata to system

Align the sample

  • move instrument to elastic position
  • calculate (hkl) of a strong allowed refelction in your scattering plane for your kf
  • if there is no allowed reflection within the available q-range, think about removing the filter and orient at
  • move stt/a4 to scattering angle
  • rotate sample for 181° minimum (sometimes SE will hinder you, then take what you get)
  • you should find at least one reflection, and the angles between refelctions should represent the symmetry of the crystal
  • if there are more reflections than expected or the angles are wrong: filter forgotten? more than one grain? - think and decide
  • if ok - move sth/a3 to maximum of the reflection. Take the one better suited for SE/other constraints
  • go to maximum of the peak, define sth/a3 for the reflection [panda: setalign((h,k,l), nn)]
  • gonio-scan in the related direction, go to max.
  • check height
  • repeat gonio-scan, until there is no relevant change
  • check the lattice parameter. Care that horizontal focus is flat for this scan.
  • adjust lattice parameter
  • check gonio, height, lattice parameter iteratively up to no relevant changes occur. care about foci
  • after last lattice parameter scan, define sth/a3
  • claculate orthogonal reflection
  • go there, you should find it immediately
  • gonio-scan, lattice parameter iteratively (remember foci. height should be ok)
  • adjust lattice patametr, fix gonios
  • in case sth/a3 does not fit perfectly for both reflections, decide about a compromise depnding on you measureing goal
  • check lattice parameters at the temperature you want to measure
  • start first inelastic scans

Good luck!!!!

panda/index.1601917825.txt.gz · Last modified: 2020/10/05 17:10 by Astrid Schneidewind