About

Pierre Ribault

I keep machines empty. Then I keep them honest about why.

I am a vacuum scientist. For more than a decade I have worked where very low pressure stops being a number and starts being a discipline: industrial electron tubes, synchrotron light sources, and now a large accelerator complex.

That path is unusual. Most people in this field stay in one of those worlds. I have lived in all three, and the crossing is the point. The same physics governs them. The cultures do not. What one community treats as obvious, the next has never had to ask. Carrying questions across that gap is most of what I do.

Where I have worked

I started in industry, in the design of miniature X-ray sources and electronic tubes, under ultra-high vacuum, down to the 10⁻⁹ and 10⁻¹⁰ Torr range. R&D on hardware meant to break new ground. I led a small team and co-signed patents.

Then a synchrotron, on the beamline side, where vacuum is the condition for the light to exist at all.

Now an accelerator laboratory, working on the vacuum systems and diagnostics of a free-electron laser. Bake stations. Residual gas analysis. Ion pumps. The slow, careful craft of getting and keeping a clean vacuum at scale.

What I build

I write software for the work I do. A fleet monitoring platform for vacuum systems, with physics built in rather than bolted on. I am also building tools that let a vacuum engineer ask hard questions and get answers grounded in real measurement, not guesswork.

Why this site exists

Physical understanding is fragile. It lives in people, it is expensive to build, and organizations lose it without noticing. I think someone should be writing it down before it goes. So I am.

Mean Free Path is where I do that. New essays land on Sundays. If that is your kind of thing, subscribe below, or write to me at hello@pierreribault.com.