2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/131966We consider a slow particle with wave function $ψ_t(\vec{x})$, moving freely in some direction. A mirror is briefly switched on around a time $T$ and its position is scanned. It is shown that the measured reflection probability then allows the determination of $|ψ_T(\vec{x})|^2$. Experimentally available atomic mirrors should make this method applicable to the center-of-mass wave function of atoms with velocities in the cm/s range.4 pages, 5 figuresQuantum Physicstext