A Pulsed Spectrometer Designed for Feedback NQR
نویسندگان
چکیده
A pulsed NQR spectrometer specifically designed to facilitate real-time tuning of pulse sequence parameters is described. A modular approach based on the interconnection of several rack-mounted blocks provides easy access to all spectrometer signals and simplifies the task of modifying the spectrometer design. We also present experimental data that demonstrates the ability of the spectrometer to increase the signal to noise ratio of NQR measurements by automatically adjusting the pulse width in the strong off-resonant comb pulse sequence.
منابع مشابه
Development of Low Frequency Pulsed NQR/NMR Spectrometer
An FPGA based NQR spectrometer has been designed for detection of N nuclei. The digital circuits required for NQR spectrometer i.e Pulse Programmer, DDS, digital receiver have been built inside FPGA. Combining FPGA chip with analog components, NQR spectrometer has been developed. N from NaNO2 is observed using same spectrometer. By adding a permanent magnet of uniform field NMR signal of proton...
متن کاملSQUID detected NMR and NQR
Ž . The dc Superconducting QUantum Interference Device SQUID is a sensitive detector of magnetic flux, with a typical flux noise of the order 1 mF Hz at liquid helium temperatures. Here F s"r2 e is the flux quantum. In our NMR or 0 0 NQR spectrometer, a niobium wire coil wrapped around the sample is coupled to a thin film superconducting coil deposited on the SQUID to form a flux transformer. W...
متن کاملIodine NQR and Phase Transitions in [N(CH3)4]2ZnI4*
Using a superregenerative NQR spectrometer, the temperature dependence of I NQR spectra in [N(CH3)4]2ZnI4 was measured between 167 and 335 K. The measurements confirm two known structural phase transitions at 219 and 257.5 K. The correspondence between the distinct regions of iodine NQR spectra and the crystal structure is discussed. The relation of [N(CH3)4]2ZnI4 to the incommensurate family w...
متن کاملNumerical Design of Composite Pulses for Polycrystalline Samples in Pulsed NQR Spectroscopy *
für Naturforschung in cooperation with the Max Planck Society for the Advancement of Science under a Creative Commons Attribution 4.0 International License. Dieses Werk wurde im Jahr 2013 vom Verlag Zeitschrift für Naturforschung in Zusammenarbeit mit der Max-Planck-Gesellschaft zur Förderung der Wissenschaften e.V. digitalisiert und unter folgender Lizenz veröffentlicht: Creative Commons Namen...
متن کاملNQR Studies of Atomic Arrangements
A very high sensitivity continuous wave NQR spectrometer was developed to detect pure NQR transitions at low frequencies (down to 200 kHz). A signal-to-noise ratio of more than 100 to 1 has been achieved at about 1.36 MHz for crystalline B 2 0 3 . Two large n B responses have been found in vitreous B 2 0 3 (NMR detected only one site) with linewidths of less than 30 kHz. A1 NQR spectra were obt...
متن کامل