No abstract

No abstract

We report on the realization and characterization of a system for the simultaneous stabilization and control of magnetic field strength and gradient in a region of 35 mm and along a given direction. The system is based on two magnetometers, each providing a field readout every 10 s, and a control unit, which real-time processes the readouts and controls the currents flowing into two compensation coils. Attenuations of 30 dB for the field strength and 20 dB for the gradient have been achieved, along with feedback loop bandwidths of 450 and 620 Hz, respectively. The method can be extended in order to noninvasively control the field strength and gradient along all three directions as well as higher-order multipole terms.

We report on a detailed measurement of the enhanced absorption Hanle effect resonances in 85Rb. The effect was analysed with an experimental setup allowing for the control of each magnetic field component within 1 mG. The characterization deals with the dependence of resonances, observed under different magnetic field conditions, on the frequency, intensity and polarization of the exciting radiation field. An analytic model that precisely describes the resonance behaviour is discussed.

An on-line toxic metal analyzer based on direct current plasma-excited atomic absorption spectroscopy was previously developed for detection of cadmium and lead species in combustion exhaust gases. In the present work the applicability of the analyzer for detection of copper species in industrial processes was investigated. The detection limit was found to be 0.17 mg/m3. Theoretical calculations showed that the detection sensitivity could be improved one order of magnitude by optimizing the background correction. Further improvement in detection sensitivity is predicted using tunable diode laser spectroscopy.