A microcomputer (IBM PC) based pulsed NMR spectrometer

Abstract

<span style="font-size:11.0pt;line-height:115%; font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family:="" "times="" new="" roman";mso-fareast-theme-font:minor-fareast;mso-hansi-theme-font:="" minor-latin;mso-bidi-font-family:"times="" roman";mso-ansi-language:en-us;="" mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">This paper describes the design and construction of a personal computer (PC) based pulsed NMR spectrometer to measure spin-lattice relaxation times in solids. The spectrometer works at 10 MHz and produces r.f. pulses of amplitude 200 V_p-p. The pulse programmer provides various pulse sequences such as 180°-<i style="mso-bidi-font-style:normal">τ</i>-90°and 90°-<i style="mso-bidi-font-style: normal">τ</i>-180°and inter pulse intervals (<i style="mso-bidi-font-style: normal">τ</i>) can be computer programmed. The rise and fall times of r.f. Pulses are less than 0.4 <i style="mso-bidi-font-style:normal">µ</i>s. The rejection ratio of the transmitter is better than 3 x 10⁷. The overall gain of the receiver system is 120 dB with a band width of 2 MHz. The recovery time of the receiver is 7 <i style="mso-bidi-font-style:normal">µ</i>s. The PC controls the spectrometer and data acquisition system. A detailed description of the spectrometer is presented.</span>