#experimental physics

Metal stock in our department’s machine shop.  Basic machining skills are often necessary to build an experiment, and so many experimental physicists are encouraged to take a course in machining.  The final project is to make a nut and bolt from scratch.

Refrigerated Electron Beam Ion Trap (REBIT)

Anion trap is an experimental physics device that captures ions for use in condensed matter experiments. A common design, pictured above, uses extremely strong magnetic fields (on the order of teslas) to accelerate a central electron beam. When a gas is released into the chamber, particles near the beam have their outer electrons ripped off by the magnetic field. The stronger the magnetic field, the more you can ionize your particles.

RefrigeratedEBITs can allow the magnetic field to become absurdly strong due to superconducting effects in the magnetic coils. These devices are capable of producing highly charged ions (HCIs). A REBIT can take xenon gas, for example, and give back Xe³⁴⁺. That’s xenon – a noble gas that loves its electrons – with 34 of its 54 usual electrons ripped off! Particles like this are extremely energetic, and surface physics experiments often investigate the interaction of these particles with metallic surfaces. These very angry HCIs can create microscopic craters in a previously clean surface.

Besides surface physics, HCIs are found in several astrophysical systems. This makes REBIT facilities one of the rare places where scientists can perform experimental astrophysics, by generating and experimenting with high charged plasmas in the lab. Highly charged ions can be found in powerful cosmic phenomena like stellar coronae and accretion disks in quasars.

Lightning Strike Lichtenberg Figure Sculpture —

Victims struck by lightning often develop red, branching patterns across their skin, often lasting several days, likely caused by delicate capillaries under the skin rupturing from the shock of the electrical discharge–a natural example of fractals. The colloquial name is “lightning flowers,” but they are also called “Lichtenberg figures” in honor of 18th century physicist Georg Christoph Lichtenberg.