Peter Baker Staff Profile
23 Mar 2022



Dr Peter Baker is an Instrument scientist working at the ISIS facility responsible for the MuSR muon instrument.


​Peter working on the MuSR Instrument


Peter began his scientific career by completing both undergraduate and doctoral degrees in physics at Oxford University. His PhD involved the study of transition metal oxides and their magnetism and superconductivity, using muon spin spectroscopy to do that. His PhD saw him come to the ISIS facility to perform experiments. Following on from his PhD Peter worked as a postdoctoral researcher at Oxford University in their physics department, then he first joined the ISIS facility as a research scientist. 

Peter is the lead instrument scientist for the MuSR spectrometer beamline at the ISIS facility. This instrument uses the technique of muon spectroscopy to analyse samples. “A lot of physical process in materials involve magnetic fields either existing or changing, what we do in experiments is send muons into the material and work out what’s going on to produce the magnetic fields they measure.” 

“Muons are almost like Goldilocks’ porridge amongst fundamental particles, they have an intermediate lifetime, longer than a lot of processes that happen in materials but not infinite, so the fact that it’s unstable means, in some cases, that it is easier to see what it’s been up to.” 

A special feature of the MuSR instrument is its ability to carry out lots of ultra-low temperature measurements, with 80% of all MuSR experiments happening at below 1K and then 65-70% of experiments happening at below 0.25K. 

When Peter started working at ISIS he largely continued in his work of studying magnetic and superconducting systems. About a year later, working in collaboration with users from Japan, Peter was studying the material Cs3C60 and found that at the very lowest temperatures it was weakly magnetic. This discovery was only possible because of the sensitivity of muons and the ease with which they allow low temperature measurements. 

During his time at ISIS Peter has developed the field of using muons to study the diffusion of ions in battery materials. He has been involved in a long collaboration with the University of Sheffield which has seen the university team develop and produce new battery materials in different ways, including the first measurements as battery cells are charged and discharged. 

In the autumn of 2021 Peter was interviewed by, and then appeared on, the Physics world weekly podcast. He spoke about the general aspects of Muons and how they can be used to study materials. 

Peter has also run ISIS’ muon training schools for the last ten years and gradually developed online learning materials to complement the in-person school with a series of industrial placement students. The online learning platform was developed as part of the SINE2020 European project with a team in Copenhagen leading work on neutron scattering content and ISIS first contributing muon content, then adding neutron content more recently. 

“It gives users the opportunity to learn some of the techniques before attending in-person schools or experiments, and then they’re able to reinforce what they have learnt afterwards. People rarely come across muon spectroscopy at undergraduate level so have little experience with the techniques when they come to do their PhDs, bringing everyone up to a basic level of understanding is very important.”  

60 second sketch: 

We ask our interviewees to answer these 10 questions, the only catch: they've got to do them as fast as they can within 60 seconds. 


If you weren’t a scientist what would you be? 

I think I would want to be a lawyer 


What is your favourite film?  

‘The Italian Job’, the original one of course! 


If you had a time machine where would you travel back to? 

Ancient Greece, I think it would be very interesting to see what Plato’s school in Athens was actually like. 


What’s your favourite book? 

‘The Remains of the Day’ by Kazuo Ishiguro 


What’s your favourite food? 



If you could have any superpower what would it be? 

Flight, I would be able to get around quickly and never be late 


Who is your favourite scientist? 

Michael Faraday 


What is your favourite type of music? 



Who would you want to play you in a movie about your life? 

James Fleet 


What’s your favourite holiday destination? 


Link to 'Materials World' article "Spying on Ions" featuring Petr's work: 
Contact: Jones, Evan (STFC,RAL,ISIS)