Muon Imaging Budgets for Buried Archaeological Cavities in Volcanic Tuff at Naples

This paper computes the muon attenuation, exposure and resolution budget for imaging buried cavities beneath Naples with cosmic-ray muons. Sight lines through 25 metres of volcanic tuff at a density of 1.6 grams per cubic centimetre present an opacity of 4000 grams per square centimetre (40 metres of water equivalent), which sets a minimum muon energy of 8.056 GeV and a transmitted vertical intensity of 2.718 per square metre per second per steradian. For a detector of 0.5 square metres with the stated acceptance and efficiency, divided among 200 image elements, the stated feature produces a flux contrast of 2.758 and reaches five standard deviations in 0.01098 days of counting, while the target precision of 0.05 per image element requires 1.336 days. A deployment of 90 days delivers a per-element precision of 0.006091, corresponding to a thickness sensitivity of 0.1523 metres. The combined angular resolution is 24.81 milliradians, of which tracking contributes 2.357 milliradians and multiple scattering at the threshold momentum 24.69 milliradians. The budget is compared with published muography of the same class of target, for which muon imaging beneath Naples has reported a previously unknown funerary chamber of the ancient Greek necropolis, detected from a detector placed in an underground cellar. Every number is computed by the accompanying script from the stated inputs. Computed, not measured.