Identification of Cosmic Ray Heavy Nuclei in an Assembly of Nuclear Photoemulsions and Solid State Nuclear Track Detectors, Using Internal Calibration

Nuclear tracks of cosmic ray heavy nuclei (22 ⩽ Z ⩽ 28) were identified in a multilayer assembly consisting of interlaid solid state nuclear track detectors (SSNTDs) and nuclear photoemulsions (NPEs). The assembly was exposed, as part of the scientific apparatus “Quartz”, aboard the Kosmos-1672 satellite. The nuclear tracks were identified in SSNTDs using the calibrating dependence of the etch rate ratio as a function of restricted energy loss. Those tracks which continued into emulsions were used to make internal calibrations in NPEs treated by the selective development method, enabling control of the registration threshold of nuclear emulsions. In the case of a detected particle with Z = 70 ± 5, the effectiveness of combining two types of detectors in the search for very heavy cosmic ray nuclei is demonstrated.