2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/106665Interaction-free measurement and quantum interrogation schemes can help in the detection of particles without interacting with them in a classical sense. We present a density matrix study of a quantum interrogation system designed for particles that need not to be perfectly absorptive and compare the results to those of the usual setup.7 pages. 7 figures. Comments are welcome. V2: Errata are corrected. Simpler modelQuantum Physicstext