  Electromagnetic fields surrounding pulsars may source coherent ultralight
axion signals at the known rotational frequencies of the neutron stars, which
can be detected by laboratory experiments (e.g., pulsarscopes). As a promising
case study, we model axion emission from the well-studied Crab pulsar, which
would yield a prominent signal at $f \approx 29.6$ Hz regardless of whether the
axion contributes to the dark matter abundance. We estimate the relevant
sensitivity of future axion dark matter detection experiments such as
DMRadio-GUT, Dark SRF, and CASPEr, assuming different magnetosphere models to
bracket the uncertainty in astrophysical modeling. For example, depending on
final experimental parameters, the Dark SRF experiment could probe axions with
any mass $m_a \ll 10^{-13}$ eV down to $g_{a\gamma\gamma} \sim 3 \times
10^{-13}$ GeV$^{-1}$ with one year of data and assuming the vacuum
magnetosphere model. These projected sensitivities may be degraded depending on
the extent to which the magnetosphere is screened by charge-filled plasma. The
promise of pulsar-sourced axions as a clean target for direct detection
experiments motivates dedicated simulations of axion production in pulsar
magnetospheres.
