The Auger Radioisotope Microscope: an instrument for characterization of Auger electron multiplicities and energy distributions

<title>Abstract</title> <p> We describe a new instrument, the Argonne Auger Radioisotope Microscope (ARM), capable of characterizing the Auger electron (AE) emission of radionuclides, including candidates relevant in nuclear medicine. Our approach relies on event-by-event ion–electron coincidence, time-of-flight, and spatial readout measurement to determine correlated electron multiplicity and energy distributions of Auger decays. We present a proof-of-principle measurement with the ARM using x-ray photoionization of stable krypton beyond the <italic>K</italic> -edge and identify a bifurcation in the electron multiplicity distribution depending on the emission of K-LX electrons. Extension of the ARM to the characterization of radioactive sources of AE emissions is enabled by the combination of two recent developments: (1) cryogenic buffer gas beam technology to introduce Auger emitters into the detection region with well-defined initial conditions, and (2) large-area micro-channel plate detectors with multi-hit detection capabilities to simultaneously detect multiple electrons emitted in a single decay. </p>. Authors: Stollenwerk, Patrick R. (ORCID:0000000176598713); Southworth, Stephen H. (ORCID:0000000277457629); Granato, Francesco; Renne, Amy; Mustapha, Brahim. DOE Contract: AC02-06CH11357