Improvement in the precision of the paleomagnetic intensity determination experiment

(1)基于Kono et al. （J.Geomag.）提出的古强度实验测量新系统。Geoelectr。该系统由(1)带温度控制装置的电炉、(2)带样品旋转平移装置的磁通门传感器、(3)带放大器的磁通门传感器、(4)位置检测装置、(5)应用恒磁场的线圈、(6)三层磁屏蔽、(7)控制所有部件的PC组成。(2)新测量系统的软件开发为了在PC上完全控制系统，开发了一个软件包，包括(1)电机控制角度检测，(2)滑动控制和位置检测，(3)磁通门信号放大和AD转换，(4)FFT信号处理和磁化计算，(5)温度控制，(6)磁场控制，(7)测量结果分析。(3)古强度测定实验利用新研制的仪器和软件，对冰岛玄武岩样品进行了热消磁和Thellier古强度测定实验。实验结果的数据分析正在进行中。

(1) A new measurement system for paleointensity experimentsBased on the idea proposed by Kono et al. (J.Geomag. Geoelectr., 43,429,1991) , a new system was constructedby Natsuhara Giken Co. This system consists of (1) electric furnace with temperature control device, (2) sample rotation-translation unit, (3) fluxgate sensor with amplifier, (4) position detection unit, (5) coil for application of constant magnetic field, (6) three-layr magnetic shield, and (7) a PC to control all of these parts.(2) Software development for the new measurement systemTo control the system completely from a PC,a software package was developed including (1) motor control angle detection, (2) sliding control and position detection, (3) fluxgate signal amplification and AD conversion, (4) signal processing by FFT and calculation of magnetization, (5) temperature control, (6) magnetic field control, and (7) analysis of measurement results.(3) Experiments of paleointensity determinationUsing the newly developed instrument and the software, thermal demagnetization and Thellier's paleointensity experiments were carried out for basaltic samples from Iceland. The data analysis of experimentatl results are now in progress.