Design Blueprint: A Plasma-Beam Shepherd: Neutralised Particle-Beam Momentum Transfer to a 170-Metre Asteroid

Design blueprint derived from the source paper (DOI 10.5281/zenodo.24180184): This paper computes a plasma-beam shepherd that directs 260,000 W of beam power at 48,000 m per second toward a 170 m asteroid of mass 6,173,857,883 kg. Beam momentum flux reduced by a coupling fraction of 0.66 gives an effective force of 3.58 N and an acceleration of 5.79e-10 m per second squared. Over 4 years the shepherd delivers 73.1 mm per second against a requirement of 23.9 mm per second for a 9,500 km displacement with nine years of warning, a margin ratio of 3.06 and a computed separation of 29,064 km. This is a computed study of a deflection system for planetary defence, with no targeting or weapon application. It is simulated, not measured. Status: DESIGN BLUEPRINT — SIMULATED, NOT MEASURED — NOT BUILT. All numbers are simulated values from the source paper's computation, deposited with this blueprint as compute.py and results.json. AI-use disclosure: Dave, an AI research system, assisted with the computation and drafting under the author's direction; author of record William Alexander Aldred.