A conventional cyclotron uses fixed magnets and a timed accelerating gap. Which describes its particle path?

• A widening spiral with two accelerating gap crossings per lap
• A fixed-radius ring with two accelerating gap crossings per lap
• A widening spiral with energy gain supplied by the magnetic field

Why use high-energy accelerator probes to study quark-scale structure rather than improve an optical microscope?

• Higher beam intensity alone resolves detail even at unchanged wavelength
• Only larger lenses can resolve quarks without changing the probe wavelength
• Shorter wavelength needs higher momentum and energy for the same probe

For a visibly curved charged-particle track, known field and travel directions let you infer charge sign from bend direction.

A charged track curves in a known uniform magnetic field, but its charge magnitude is unknown. What does its transverse curvature determine?

• The full momentum, even if its direction along the field is unknown
• The transverse momentum divided by charge magnitude, p_perp/|q|
• The transverse momentum alone, without needing the charge magnitude

Protons (charge +e) gain 800 MeV of kinetic energy in a linac with 2000 accelerating gaps. Neglect losses. What average effective accelerating voltage per gap is needed, in MV?

How can detector measurements help identify a passing charged particle?

• Read momentum alone; every pair of particles with equal momentum must have equal mass
• Use bend direction alone; every particle species has a different sign of electric charge
• Compare energy loss, flight time and Cherenkov light with particle predictions

A thin target receives a uniform beam flux. The flux doubles while target count and beam energy stay fixed. Neglect beam attenuation. What happens to the interaction event rate?

• It stays fixed because the interaction cross-section has not changed at this energy
• It doubles because rate is proportional to flux under these conditions
• It halves because doubling the beam flux divides the target nuclei between the particles

A student says detectors film the collision itself. Which description matches how charged-particle tracks are reconstructed?

• Fit a path through hits recorded in several sensor layers
• Follow light reflected from each particle with a camera
• Read a particle's trajectory directly from the beam clock