Cosmic-ray spallation in Earth’s upper atmosphere occasionally produces beryllium-10
PHYSICS · Multi-part · A Level · Physics · Particles and radiation · Particles and radiation
Problem
Cosmic-ray spallation in Earth’s upper atmosphere occasionally produces beryllium-10, which quickly slows to rest inside atmospheric molecules. Within milliseconds a single 410Be nucleus is recorded to undergo the following time-ordered sequence:
Step 1 (at t=0): emission of a β+ particle and an associated light neutral lepton.
Step 2 (at t=1.0×10−3s): emission of an α particle and a high-energy photon.
No other particles are detected.
Assume the beryllium nucleus and all reaction products remain free after the final emission.
(a) Determine the nuclide produced immediately after Step 1 and write the corresponding nuclear equation.
(b) Using the intermediate nuclide from part (a), write the nuclear equation for Step 2.
(c) Combine Steps 1 and 2 into a single overall equation relating the original 410Be nucleus to the final stable nucleus and all emitted particles.
(d) Verify quantitatively that lepton number, nucleon number, and electric charge are each conserved in the overall process described in part (c).