boron

An aluminum sphere the size of a large globe sits in a neutron beam and answers each hit with a precise note. Inside the sphere there is nothing but nitrogen and eleven tiny steel balls, each the size of a pinhead. When a neutron enters the sphere, it knocks a particle out of a nitrogen atom, and that jolt turns into an electrical signal.

The antiproton beam hits the plate, and each impact bursts into a shower of charged particles. In the GBAR experiment at CERN, this picture is captured not by a sophisticated detector but by an ordinary industrial camera without a lens, pressed against the vacuum window from the outside.

Imagine three witnesses who saw the same event. Two tell the same story, the third tells a different one. Whom do you believe? This is exactly the situation in astronomy when measuring carbon in the star J0815+4729, an ancient object with a record-low iron abundance (carbon is one of the key elements used to infer the properties of the…

The neutron is a particle that usually sits in the atomic nucleus and doesn't disappear. But some theories suggest that occasionally it might transform into its invisible twin — a particle that ordinary detectors can't catch.

In the layered crystal CrSBr, the magnetic moments of atoms are arranged like notes in a score: within each layer they point in the same direction, but between layers they point in opposite directions. This antiferromagnetic melody plays up to 132 kelvin, beyond which thermal motion destroys the order.

A fusion reactor is like a super-hot furnace where plasma reaches millions of degrees. The walls are made of tungsten, the most refractory metal there is. But even tungsten needs protection: fast particles from the plasma bombard the surface and knock atoms loose. These ejected atoms enter the plasma and cool it down, like a spoonful of cold milk in hot tea.

In a quiet room, you can hear the faintest whisper. Likewise, in the hydrogen atom, the lightest of all, an uninvited guest is easier to spot. That guest could be the Z' boson, a mediator particle of a new force predicted by many unification theories. The Standard Model already has its own mediator — the Z boson.

In boron neutron capture therapy (BNCT), the patient receives an injection of the isotope boron-10, which selectively accumulates in tumor cells. The tumor area is then irradiated with a beam of thermal neutrons.

A tiny defect in a boron nitride crystal behaves like a microscopic indicator bulb. Shine light on it, and it glows, with the shade shifting with temperature: the warmer it gets, the redder the glow.

The Universe is a genius chef, and the Big Bang is its perfect recipe. Hydrogen rose fluffy, helium melted tender, but lithium-7 seems oversalted: theory predicts three times more than astronomers find in the oldest stars. This imbalance, the 'lithium problem,' has spoiled cosmologists' appetite for decades.

On one side of the scale lies all the matter in the Universe; on the other, all the antimatter. According to the laws of physics, at the moment of the Universe's birth, the pans should have been balanced. But we see one pan tipping: around us are stars, planets, people, and almost no antimatter. This imbalance is one of the greatest mysteries.

A pool of the purest water, into which tiny, almost invisible droplets occasionally fall. Each leaves a barely perceptible ripple, and capturing it requires years of patience. That is what the hunt for solar neutrinos looks like in the DEAP-3600 detector — a huge vat of liquid argon hidden deep underground.

A pot of boiling soup bubbles away, and you'd love to know how hot individual droplets are inside. But you can only dip your thermometer at the edge, where things are calmer. Laser fusion is a bit like that: a powerful laser pulse hits a target, creating a cloud of fast protons.

A pinch of salt falls into water, and sodium and chlorine ions scatter, surrounded by water molecules. Now, instead of an ion, a positron (an antiparticle, the electron's twin but with a plus instead of a minus) joins the molecular crowd.

A gold speck the size of a hundred atoms catches a beam of light, and heats up. In everyday life, that's no big deal, but in the world of nanotechnology, this tiny heat can ruin a biosensor or fry a microchip. You can't just put a fan on it: at these scales, heat gets trapped like in a thick winter coat.

Diamond is the hardest natural material and usually does not conduct electricity. But if you add a few foreign atoms to its crystal lattice, it can become a semiconductor, like silicon in computer chips.

Fusion, the merging of a proton with a boron-11 nucleus, promises a near-perfect energy source: no dangerous neutron flux, just a stream of charged particles that can be directly converted into electric current. But there's a fundamental problem: the Coulomb barrier.

A laser beam as faint as a whisper of light has stirred a thorium-229 nucleus into a higher energy state. Most nuclei demand a blast of energy, but thorium-229 has such a tiny energy gap that even this gentle nudge works.

Inside the Sun, invisible nuclear transformations occur every second. One of them is the birth of boron-8: a beryllium-7 nucleus captures a passing proton and momentarily becomes a new element. This step kicks off a chain that ends with the emission of a neutrino — a particle capable of passing straight through Earth.

In a dark tank holding thirty tons of water, the liquid glows when a ghostly particle streaks through. Neutrinos barely interact with matter, but occasionally they bump into atoms, and a flash is born. To catch it, a special substance, a liquid scintillator, is added to the water to amplify the light.

A solid electrolyte is like a sponge for lithium ions. In a regular lithium battery, ions float in a liquid, like fish in an aquarium. In a solid-state battery, they have to squeeze through the crystal lattice, like through narrow corridors.

Neutrinos are tiny particles that zip through Earth, barely noticing it. In the MicroBooNE experiment, they are caught in a tank of liquid argon. When a neutrino strikes an argon nucleus, it produces an electron and protons, like splashes from a stone thrown into water.

Hidden inside a zinc oxide crystal is a quantum duo: a tin atom and a lithium atom sitting side by side. Their bond is so tight that the electron captured by this pair seems to live on the tin, while the lithium merely plays along. This complex was long sought after, but only now has it been deliberately created and identified by its characteristic glow.

The proton is not a solid ball. Its charge, mass, and other properties are distributed differently in space, and each property has its own radius. Physicists have long been able to measure where the proton's charge is concentrated and where its mass lies.

Every time deuterium and tritium fuse in a fusion reactor, a fast neutron flies out. It can turn one substance into another — for example, create valuable isotopes for medicine. Today such neutrons cost a fortune, because there are few experimental facilities and they rarely operate.

In a giant particle accelerator, where protons traveling at nearly the speed of light smash into a neon target, charmed baryons are born — particles that live for less than a billionth of a second.

A thin crystal of hexagonal boron nitride is a relative of graphite, but transparent and insulating. Occasionally, single defects appear in its lattice: a boron or nitrogen atom is missing, leaving a trap for electrons. Such a trap can absorb light and re-emit it, like a tiny flashlight.

At the heart of a neutron star, matter is squeezed so tightly that protons and neutrons transform into heavier particles — hyperons. These particles resemble neutrons but contain a strange quark. For a long time, physicists couldn't understand how a star with hyperons inside could be as heavy as observations show.

In a particle accelerator, the anti-lambda particle is a rare guest. It is born on the fly, lives for a tiny fraction of a second, and usually decays on its own. But sometimes it manages to collide with an ordinary proton, and then a whole shower of light particles is born: kaons, pions.

Dark matter is invisible, but you can catch it on the rebound. Hydrogen embedded in a carbon film acts like a billiard ball: when a dark matter particle hits it, the proton flies out. That ejection is the signal you're looking for.

A single light source in a thin layer of boron nitride flashes on and off in a couple of nanoseconds. You can create many such sources in the material, but each one used to work on its own. In the new work, they were made to glow together, like musicians playing in unison.

In an underground hall at Fermilab, a huge tank holds liquid argon — a transparent fluid at minus 186 degrees. When an invisible neutrino flies into the tank, it occasionally strikes an argon nucleus, and a short track of charged particles flashes.

A dense piece of plastic the size of a coin flashes when an invisible particle hits it. That's how scintillators work — materials that turn radiation into faint light. They're usually made from fragile crystals or expensive polymers. But now there's a simpler option: plain polyurethane, the stuff used to mold furniture foam and shoe soles.

In the first minutes after the Big Bang, the Universe was like a blazing hot stove. On it, according to the 'recipe' of the standard theory, hydrogen, helium, and a bit of lithium were supposed to cook. But telescopes see only a third of the lithium that this recipe calls for.

Inside a seven-meter spectrometer that looks like a tall column, fragments of a decayed neutron are born. To catch them, you need silicon wafers the size of a dining table and as thick as a finger.

Water in a kettle heats to 100 degrees, and stops being water, turning into steam. Something similar happens to atomic nuclei when they are smashed together at enormous speeds in the Large Hadron Collider.

In a dark room, you might notice a faint blue glow around some radiation sources. This is Cherenkov light: it appears when a charged particle travels through a medium faster than light can propagate in it. The result is a light shock wave, similar to the sonic boom from a supersonic jet, but made of photons.

Heavy water (the kind where ordinary hydrogen is replaced by its beefier cousin, deuterium) was subjected to an electric current. Palladium settled on the cathode, and in this modest electrochemical bath, detectors repeatedly caught something unexpected: traces of slow neutrons.

Deep inside stars, light nuclei fuse, giving birth to helium and streams of neutrons. On Earth, we recreate this process by combining deuterium and tritium — special isotopes of hydrogen.

A thin film of thorium dioxide, just 10 nanometers thick, is deposited on a steel disk. A laser pulse strikes it, but instead of the expected glow, the detector catches a stream of electrons.