title: Confocal fluorescent imaging of tracks from heavy charged particles utilising new Al2O3:C,Mg crystals.
abstract: A completely optical, non-destructive imaging of tracks in a fluorescent crystal provides a new way to detect and to assess doses from heavy charged particles and neutrons. The technique combines confocal fluorescent microscopy with a new radiation-sensitive, luminescent material based on aluminium oxide single crystals doped with carbon, magnesium and having aggregate oxygen vacancy defects (Al2O3:C,Mg). Radiation-induced colour centres in the new material have an absorption band at 620 nm and produce fluorescence at 750 nm with a high quantum yield and a short, 75 +/- 5 ns, fluorescence lifetime. Three-dimensional spatial distribution of fluorescent intensity allows one to obtain depth-dose distributions and to discriminate between high- and low-linear energy transfer radiations. Images of single tracks produced by different types of radiation have been obtained. Irradiations with a calibrated 241Am alpha source showed high efficiency for track detection. Thermal neutrons were detected using a nuclear reaction with a 6LiF radiator and production of alpha particles and tritium ions. Fast neutrons were detected using recoil protons produced in a polyethylene radiator installed in front of the crystalline detector. Three-dimensional reconstruction of a recoil proton propagating through the crystal was demonstrated.
authors.affiliation: Landauer, Inc., Stillwater Crystal Growth Division, 723 1/2 Eastgate Road, Stillwater, OK 74074, USA. makselrod@landauerinc.com
authors.forename: Mark S
authors.initials: MS
authors.lastname: Akselrod
authors.forename: R Craig
authors.initials: RC
authors.lastname: Yoder
authors.forename: Gleb M
authors.initials: GM
authors.lastname: Akselrod
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry* / Q000528:radiation effects*; D002244:Carbon / Q000737:chemistry / Q000528:radiation effects; D003460:Crystallization; D004307:Dose-Response Relationship, Radiation; D004867:Equipment Design; D019544:Equipment Failure Analysis; D020450:Heavy Ions; D018499:Linear Energy Transfer; D008274:Magnesium / Q000737:chemistry / Q000528:radiation effects; D008422:Materials Testing / Q000379:methods*; D018613:Microscopy, Confocal / Q000379:methods*; D008856:Microscopy, Fluorescence / Q000379:methods*; D011829:Radiation Dosage; D013819:Thermoluminescent Dosimetry / Q000295:instrumentation / Q000379:methods*
chemical_list: D002244:Carbon; D008274:Magnesium; D000537:Aluminum Oxide