In the next twenty milliseconds you will be stripped of everything you own, accelerated to 84% of the speed of light, and slammed into a block of tungsten. Then the interesting part starts.
No steering. No brakes. No respawn — but you do become data.
~20 msdoor to detector, real time
84% ctop speed, no ticket issued
1collision that matters
Headphones recommended — the soundtrack is synthesized live in your browser. One continuous flight, about three minutes; it does not stop to explain itself. The whole ride is written out below.
The ride doesn't stop to explain itself — this is the reading layer: every stop, in order, with the numbers. It is also the ride for keyboard-only readers, reduced-motion settings, and browsers without WebGL.
You start as an H⁻ ion — one proton (you), holding two borrowed electrons. Fifty times a second, an electric field plucks trillions of you out of a caesium-laced hydrogen plasma and shoves you toward the first accelerator. Think of it as the dispatch queue.
35 kVextraction — what first gets you moving
The radio-frequency quadrupole does two jobs at once: it accelerates you, and it chops the continuous stream of ions into tidy bunches locked to a 202.5 MHz radio wave. From here on you never travel alone — you are one message in a batch.
665 keVenergy leaving the RFQ
Four tanks of drift tubes. Inside each tube the field can't touch you; in the gaps it shoves you forward — timed so you only ever feel the push, never the pull. Each tube is longer than the last, because you're faster when you reach it. By the end of the line you're doing over a third of the speed of light.
70 MeV≈ 37% of light speed
This is the synchrotron's trick for merging new beam into a ring already full of protons: you arrive negatively charged, so the magnets bend you into the ring while the circulating beam holds its line — then a foil a third of a micrometre thick strips both electrons off mid-flight. You came in as an H⁻ ion. You leave as a proton.
0.3 µmof aluminium oxide — changes what you are
Ten big dipole magnets bend you around a 163-metre ring while RF cavities kick you harder every lap — roughly ten thousand laps in ten milliseconds, packed with 2.5×10¹³ colleagues into two bunches. The ride shows you just two laps of it, in heavy slow motion; by the last one you're at 84% of the speed of light.
800 MeVin ~10,000 laps · 10 ms
Kicker magnets fire in under 100 nanoseconds — in the gap between bunches — and punt the whole beam out of the ring in a single turn. You're now on EPB1, a 150-metre straight with 68 magnets keeping the bunch tidy. Four of every five pulses go this way, to Target Station 1; the fifth peels off to TS2.
<100 nsfor the kickers to fire
A 10-millimetre wafer of graphite sits dead ahead — in the beam, on purpose. Fewer than 5% of protons hit anything inside it; those collisions make pions that decay into muons for the µSR instruments on either side. You're in the other 95%: straight through, barely grazed.
<5%of protons interact — you fly on
Tungsten plates, tantalum-clad, the whole stack about the size of a shoebox. You hit a nucleus at 84% of light speed and stop existing as a free proton — the nucleus boils, evaporating ten to fifteen neutrons. The point of view survives the crash: you are now one of them, doing ~6% of light speed in a direction nobody chose.
~10–15neutrons chipped off per proton
Fast neutrons are useless for measuring atoms — wrong wavelength. So you ricochet through a pocket-sized tank of room-temperature water, shedding energy with every bounce until you move no faster than the molecules around you. From ~20,000 km/s to 2.2 km/s in a few dozen collisions.
2.2 km/sthermal — wavelength ≈ 1.8 Å
The shielding monolith absorbs everything that isn't aimed down a beam port — you happen to be. Now it's a long, quiet, dead-straight flight to an instrument, and the clock is the whole point: slow neutrons arrive late, fast ones early, so your arrival time is your wavelength. Time-of-flight is structured logging.
18beam ports fan out around TS1
Inside the instrument you graze the sample — a crystal, say — and its planes of atoms deflect you at an angle that encodes exactly how they're spaced. A detector tube swallows you, your arrival time is written down, and everything you just lived becomes +1 in one bucket of a histogram. Science is the post-processing.
+1 countone detector, one slice of time
Simplified, like everything on this site: the geometry is schematic, the clock is dilated by a different amount at every stage (up to ~×10⁸), the synchrotron shows two laps instead of ~10,000, and the instrument at the end is a generic diffractometer rather than any real beamline. The numbers are real ISIS figures — see isis.stfc.ac.uk. One liberty is flagged where it happens: a real proton's point of view ends at the tungsten; the ride hands you to a neutron so you can finish the journey the beam actually makes.