In this section
HiFi
HiFi allows magnetic fields more than 100,000 times stronger than the Earth's field (up to 5 Tesla) to be applied to samples. This capability enables, for example, the investigation of solar cell materials, the testing of theories of magnetism, and the timing of chemical reactions. The instrument also offers laser excitation capability, allowing muon spin relaxation studies of optically stimulated molecules to be performed.
Instrument scientists
To find out more about each team member, click the + symbol.
James Lord
Instrument scientist
Koji Yokoyama
Instrument scientist
Mark Telling
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
HiFi Laser has a high-power Nd:YAG laser system, providing a 1064 nm pulse running at 25 Hz. The high energy pulse (~2 J/pulse) can then be used to generate harmonic wavelengths (up to the 5th harmonic) and pump an optical parametric oscillator (OPO) for tuneable wavelength. The OPO wavelength can cover from 410 to 1900 nm with varying power (~10 mJ/pulse or less) depending on the wavelength. For sample environment, HiFi’s CCR is normally used for changing sample temperature. Optical sample cells are available and can be mounted on the CCR.
- View the HiFi user manual.
- More information: Yokoyama, K., et al. “The new high field photoexcitation muon spectrometer at the ISIS pulsed neutron and muon source.” Review of Scientific Instruments 87.12 (2016).
Related resources
HiFi Laser
Overview
The HiFi Laser is a laser illumination facility for light-pump muon-probe experiments studying material’s excited states. The pulsed muon beam at ISIS and nanosecond laser pulses from HiFi Laser enables an arbitrary delay between the pulses, allowing access to a wider range of timescales. Applications include studies on photovoltaic materials, where one can measure charge carrier lifetimes upon optically generating carriers.
Since illumination experiments are still considered as a new area in μSR studies, interested PIs are strongly recommended to consult with the instrument scientists before submitting beamtime proposals.
Sample environment
HiFi has the following sample environment equipment:
- Dilution fridge (30 mK – 300 K)
- He4 cryostat (1.5 K – 300 K)
- Flow cryostat (4 K – 400 K)
- CCR (10 K – 600 K)
- Reflector furnace (300 K- 1500 K)
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).
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.
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.
Recent publications
Instrument reference
All publications and datasets based on experiments using HiFi should cite that the data is collected by DOI: 10.5286/isis.instrument.3647. 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.