Design Blueprint: A Gas-Filled Multipass Cell Compressor Sized by Per-Pass B-Integral and Total Spectral Broadening

Design blueprint derived from the source paper (DOI 10.5281/zenodo.24155310): This paper presents a computed design for a Herriott-type multipass cell that compresses 1 mJ, 250 fs pulses from an Yb amplifier toward the few-tens-of-femtoseconds range. The sizing follows from applying the relevant intensity, thermal, nonlinear and geometric bounds at a single stated operating point, with every number produced by a deposited computation. The headline result is 36 passes at 0.28 rad of nonlinear phase each, a total B-integral of 10.1 rad, a spectral broadening factor of 8.9, an output duration of 32 fs from 250 fs input, a throughput of 0.87 giving 0.87 mJ out, and an outpu 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.