Linac Spec Schema

device_class: therapy            # therapy (vs diagnostic)
photon_energies_mv: [6, 15]      # array
electron_energies_mev: [6, 9, 12, 16, 20]
dose_rate_mu_min: 600
srs_mode_dose_rate_mu_min: 800
mlc_type: Millennium
mlc_leaf_count: 120              # 80 | 120
obi_kv_imaging: true
cbct_capable: true
rapidarc_vmat: true
imrt: true
igrt: true
srs_capable: true
sbrt_capable: true
sid_cm: 100
gantry_rotation_deg: 370
couch_type: Exact IGRT
commissioning_required: true     # always true
state_license_required: true     # always true
qmp_required: true               # qualified medical physicist
rso_required: true               # radiation safety officer
iec_60601_compliant: true
tg_142_qa_schedule: true         # AAPM TG-142

Rationale

Therapy devices have a different acceptance/operation profile than any imaging modality. The schema makes the commissioning + physics + licensing requirements first-class so buyers and sellers can't accidentally elide them. MLC leaf count, OBI/CBCT, and RapidArc are the three most-common license/hardware swings that drive deal value.