Development of Ultra-Low Field NMR Detection System for Underground Resources using Highly Sensitive Magnetic Sensor

核磁共振（NMR）是一种原子吸收和辐射电磁能量的现象，其频率与施加在物体上的静态场相对应。核磁共振测井工具是地球磁场-核磁共振的应用之一。该技术是利用电磁场探测多孔油藏中1^H质子的核磁共振信号来勘探油藏的一种方法。我们成功地获得了1^H的核磁共振谱，信噪比大于7。因此，我们已经开发出一个SQUID-EMF-NMR系统原型，作为核磁共振测井工具的基础。

Nuclear magnetic resonance(NMR) is a phenomenon that atoms absorb and radiate electromagnetic energy at a frequency corresponding to a static field applied to the object. One of the applications of EMF(Earth Magnetic Field)-NMR is NMR logging tool. This technology is a method to prospect oil reservoir by detecting the NMR signal of 1^H protons in porous oil reservoir in EMF. We have successfully obtained the 1^H NMR spectrum, which has a signal to noise ratio(SNR) of more than 7. Therefore we conclude that we have developed a prototype of SQUID-EMF-NMR system as a basis for NMR logging tool.