Rühm Werner, Mares V, Pioch C, Weitzenegger E, Vockenroth R, Paretzke H G
Helmholtz Zentrum München, National Research Center for Environmental Health, Institute of Radiation Protection, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany.
Radiat Environ Biophys. 2009 Apr;48(2):125-33. doi: 10.1007/s00411-009-0219-y. Epub 2009 Feb 27.
Air crew members and airline passengers are continuously exposed to cosmic radiation during their flights. Particles ejected by the sun during so-called solar particle events (SPEs) in periods of high solar activity can contribute to this exposure. In rare cases the dose from a single SPE might even exceed the annual dose limit of 1 mSv above which dose monitoring of air crews is legally required in Germany. Measurements performed by means of neutron monitors have already shown that the relative intensity of secondary neutrons from cosmic radiation is enhanced during an SPE, particularly at regions close to the magnetic poles of the Earth where shielding of the cosmic radiation by the geomagnetic field is low. Here we describe a Bonner sphere spectrometer installed at the Koldewey station at 79 degrees N, i.e. about 1,000 km from the geographic North pole, which is designed to provide first experimental data on the time-dependent energy spectrum of neutrons produced in the atmosphere during an SPE. This will be important to calculate doses from these neutrons to air crew members. The system is described in detail and first results are shown that were obtained during quiet periods of sun activity.
机组人员和航空公司乘客在飞行过程中持续受到宇宙辐射的照射。在太阳活动频繁的时期，所谓的太阳粒子事件（SPEs）期间太阳喷射出的粒子会增加这种照射。在极少数情况下，单次SPE产生的剂量甚至可能超过每年1毫希沃特的剂量限制，在德国，超过这个剂量就需要对机组人员进行法定的剂量监测。通过中子监测器进行的测量已经表明，在SPE期间，宇宙辐射产生的次级中子的相对强度会增强，特别是在靠近地球磁极的区域，那里地磁场对宇宙辐射的屏蔽作用较弱。在此，我们描述了一台安装在北纬79度的科尔迪维站的邦纳球谱仪，该站距离地理北极约1000公里，其设计目的是提供关于SPE期间大气中产生的中子随时间变化的能谱的首批实验数据。这对于计算这些中子对机组人员的剂量至关重要。本文详细描述了该系统，并展示了在太阳活动平静期获得的首批结果。
