A high-resolution multipurpose FT nmr spectrometer

F. Caron , M. Guéron , Nguyen Ngoc Quoc Thuy , R.F. Herzog

An FT nmr spectrometer is by definition complex : many users and uses, at least three nuclear frequencies, numerous excitation patterns and sophisticated data-processing methods. Hence such machines are often unwieldy for the designer, builder, operator and end-user. We have set ourselves the goal of building a machine which can be operated with hardly any training by users, and which can be easily maintained or modified by others than the building team. The design is based on the repetitious use of simple methods. In the analogic part, the three nuclear channels are built alike, pulsing, phase-switching etc. are all done at the intermediate frequency, and most systems are broad-band, notably the transmit/receive switches. A bus carries the logical controls. Receiver recovery time is 8 μs, enabling solid-state type, broad lines to be measured. The spectrometer is multinuclear. Quadrature detection is used. A special design simplifies probe building. The interface between the analogic part and the computer is also built around a bus. It is easily programmed, and it can be extended. Data are accumulated as 32-bit words, thus avoiding memory saturation. The acquisition, under computer control, is easily programmed but limited to a total spectral width of 28.5 kHz. The programs, written in FORTRAN, make extensive use of subroutine libraries which manage the interactions of the computer and its peripherals, notably the spectrometer interface and the user's console. The programs are thus reduced mostly to CALL statements. They are easy to understand, maintain or create. User-software communications are fast, extensive, in English. Words are keyed-in by their first letter and printed in full. No mnemonics are used. Lists of available commands, program nesting and abundant information provided by the programs minimize the dependence on introductory manuals. Essential for the speed and ease of communications is the use of a CRT console, with graphics capability.

Mots clés: computerised spectroscopy; magnetic resonance spectrometers; nuclear channels; pulsing; bus; logical controls; multinuclear; computer control; peripherals; spectrometer interface; user's console; high resolution multipurpose FT NMR spectrometer; phase switching; broad band; transmit switch; transmit receive switch; quadrature detection; data acquisition; data processing; nuclear frequency

Domaines: Articles anciens

F. Caron, M. Guéron, Nguyen Ngoc Quoc Thuy, R.F. Herzog. A high-resolution multipurpose FT nmr spectrometer. Revue de Physique Appliquée, 1980, 15 (7), pp.1267-1274. ⟨10.1051/rphysap:019800015070126700⟩. ⟨jpa-00244849⟩