On the update and modifications of the M-42 radiation detector for usage in mixed radiation fields – from aircraft to space

Abstract

The German Aerospace Center (DLR) Institute of Aerospace Medicine developed small and low power consumption radiation detectors for applications in various radiation fields which will be used on the Orion Artemis 1 mission of National Aeronautics and Space Administration (NASA) to the moon. These so-called M-42 radiation detectors have been already tested extensively for example on two MAterialPHysikalische Experimente Unter Schwerelosigkeit (MAPHEUS) sounding rocket missions. Due to the properties of such small measuring devices, they are suitable for measurements in aviation in order to improve the understanding of the radiation field at aviation altitudes. For such an application usability of the device is important to ensure acceptance. A main purpose of this work was to prepare the system for applications in aviation by improving the acceptance. Therefore, it was updated in various ways. A display and a push-button have been installed which enables the user to operate the device without external peripherals. In addition, the monitoring of environmental parameters was extended by installing a new air pressure sensor in order to investigate the correlation between cabin air pressure and flight altitude. The measuring energy range was extended by more than a factor of two. Additionally, to the hardware modifications the firmware of M-42 has been improved regarding reliability and efficiency of the commands. A Graphical User Interface (GUI) has been developed and implemented which enables the user to configure the device as well as to perform the necessary data processing and evaluation. Measurements at the Heavy Ion Medical Accelerator in Chiba (HIMAC) and during the flights to Japan and back proved the positive effects of the modifications and provided the pressure-altitude correlation. It was found that the take-off and landing phases are clearly reflected in the changes of the cabin air pressure. During cruising flights, several changes in altitude are also pronounced in the cabin air pressure. The comparison of the obtained data with simulation results shows a high correlation which proves the high accuracy of M-42. A long-term measurement was performed to prove the battery lifetime (37 days) and also showed the long-term stability of the pressure sensor. Therefore, it can be concluded that the aims were fully accomplished.