The ISIS muon group supports the following pieces of software for the analysis and interpretation of muon data.


WiMDA is Francis Pratt's Muon Data Analysis program for Windows. It currently recognises the following raw data formats:

PSI (BIN and DAT formats from GPS/LTF/GPD/DOLLY, NEMU format from LEM)
KEK (pi port and mu port)
TRIUMF (TRI format)

WiMDA is now complete enough for most forms of basic muon data analysis, but various additional features are still under development.

Versions currently expire after six months; users should download a newer version at least every six months to keep up with bug fixes and new features.

WiMDA can be downloaded from the WiMDA webpage.



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.

This program has been written by James Lord at the ISIS Pulsed Muon Facility. 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.

The old Windows-only version is still available but is no longer actively maintained: quantum.zip. Old Instruction Manual for that version (PDF).  There are also some examples of the use of Quantum to help you on your way.



For some while ISIS has been using Nexus to store raw data, writing files with a structure set by the Instrument Definition found here. Following a period of use, and with the introduction of a new data acquisition system, it became clear that a substantial revision of this Definition was needed; this has been carried out, and a proposal for a revised Instrument Definition can be found here.

As Nexus is a candidate for a future muon data exchange format we're keen to hear views on the proposed new ISIS Definition - what's been missed, and whether changes could be made to make the proposed Definition more useful for data exchange. As we're hoping to start writing data conforming to this new Instrument Definition early in 2008, we'd be grateful if you could make your comments before the end of 2007.

Comments should be sent to Stephen Cottrell, from whom example data files and Fortran 77 read routines can be obtained. Further information about the Nexus data format can be found at http://www.nexusformat.org.


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