A Programmable Pulse Sequence Generator for High Temperature Low-Field NMR Apparatus

The stable operation of pulse sequence generators at high temperatures (200°C) has been an important issue for some time in the application of nuclear magnetic resonance (NMR) apparatus for oil exploration. The application of system-in-package (SiP) technology was used to improve the temperature-resist grade of the hardware platform. A pulse sequence generator that meets the requirements of accurate phase and adjustable frequency during NMR apparatus in high temperature environments was designed and implemented. At ambient temperatures of up to 200°C, experimental results show that the delay times of the rising and falling edges of the pulse are 3.2 and 3.35 ns. respectively. The eye diagram Q factor of the critical path is not less than 15, and the Bit Error Rate (BER) is not more than 10 –50 . The experimental results show that a pulse sequence generator can meet the requirements of high temperature NMR apparatus, and can also provide a template for the design of an NMR pulse sequence generator for special fields of application, such as deep sea surveys and aviation.