In this section
MuSR
MuSR is a general-purpose muon instrument primarily used to study superconductors and magnets. It is particularly well-suited to measurements at ultra-low temperatures because samples can be cooled outside the instrument before the experiment. The Super-MuSR project is now underway to significantly upgrade the instrument with order-of-magnitude improvements in counting rate and time resolution.
Instrument scientists
To find out more about each team member, click the + symbol.
Alex Louat
Instrument scientist
Peter Baker
Instrument scientist
Rhea Stewart
Instrument scientist
We support a wide range of science on this instrument and will put you in touch with the Muon Group team member who is best able to support your experiment.
Technical information
MuSR is a 64-detector µSR spectrometer that can be rotated through 90° to enable either longitudinal or transverse measurements. Zero field measurements can be made in either orientation. Longitudinal fields of up to 3200 G and transverse fields up to around 800 G can separately be applied.
Sample temperatures in the range of 40 mK to 1000 K can be produced using a variety of sample environment equipment, from dilution fridges and sorption cryostats, through helium cryostats to furnaces. The muon beam spot is the smallest available at ISIS, but flypast measurements are not possible because cryostats are prepared off-beam to make best use of beamtime.
The instrument count rate is around 70 MEv/hour with the surface muon beam (p ~ 28.7 MeV/c) having a FWHM around 50 ns and 40 pulses per second.
Related resources
Software
Mantid
The Mantid project provides a framework that supports high-performance computing and visualisation of materials science data. Mantid has been created to manipulate and analyse muon spectroscopy data, but could be applied to many other techniques. The framework is open source and supported on multiple target platforms (Windows, Linux, Mac). Download Mantid
WiMDA
WiMDA is Francis Pratt’s Muon Data Analysis program for Windows. It currently recognises the following raw data formats:
- ISIS (NEXUS, MACS and MCS formats from MUSR/EMU/DEVA/HiFi/ARGUS/CHRONUS)
- PSI (BIN and DAT formats from GPS/LTF/GPD/DOLLY, MDU format from HAL9500, LEM data via conversion to BIN format)
- KEK (pi port and mu port)
- TRIUMF (TRI format)
Versions currently expire after 24 months; users should download a newer version at least every 24 months to keep up with bug fixes and new features.
Download from the WiMDA site or GitHub.
QUANTUM
QUANTUM simulates the evolution of muon spins interacting with nearby nuclei or electrons, using the density matrix method. Interactions include dipolar, hyperfine, quadrupolar, and Zeeman energy. It can model RF resonance, or relaxation processes caused by changes of site or charge state.
The program has been written by James Lord at the ISIS Neutron and Muon Source. You may use it freely for your muon data analysis, but please acknowledge use of the program in any resulting publications with the following reference: ‘Computer simulation of muon spin evolution’, J.S. Lord, Physica B 374-375 (2006) 472-474
QUANTUM now runs within Mantid, and so can run on any Windows, Mac or Linux computer capable of running Mantid. It takes advantage of Mantid’s data handling and plotting capabilities, and can fit simulations to experimental data. Download QUANTUM from the Script Repository within Mantid.
Instruction Manual for the new version in Mantid, including installation instructions (PDF) – this is also on the Script Repository.
Please report any errors or problems to James Lord – please include enough information to enable the problem to be reproduced.
Learning resources
Nature primer: Muon spin spectroscopy
Textbook: Muon Spectroscopy: An Introduction
Online learning: PaN Training
Recent publications
Instrument reference
All publications and datasets based on experiments using MuSR should cite that the data is collected by DOI: 10.5286/isis.instrument.2152. Experiment DOIs follow the format 10.5286/ISIS.E.RBXXXXXXX, where XXXXXXX is the 7-digit experiment (RB) number and these can be viewed via the Data Gateway.