An Novel Atomic Scalar Magnetometer Using Laser

The measurement precision of commercial atom scalar magnetometer is relatively backward compared with that of quantum magnetometer. However, the application of quantum magnetometers such as SERF requires more stringent environmental background requirements, which is not suitable for magnetic field measurement in the geomagnetic environment. The purpose of this paper is to design a 4He atom scalar magnetometer using ECDL laser. Compared with the conventional atomic scalar magnetometer, this magnetometer has higher measuring precision and can work normally in the geomagnetic environment. In order to achieve the above goals, the sensitivity formula of the atomic scalar magnetometer is first deduced and calculated, and the key physical factors that directly affect the sensitivity are the optical pumping rate, transverse relaxation rate, and longitudinal relaxation rate. Then, the light source and 4He cell are determined as key components which affect sensitivity. On this basis, the optical path of the 4He atomic scalar magnetometer using laser is designed in this paper. The light path ensures the stability of the laser wavelength of 1083.207nm by the saturation absorption spectrum method, and it ensures the circularly polarized light enters the 4He cell through the combination of various optical components. This paper also studies the electric excitation technology of the 4He cell. And, combined with simulation experiments, the High-Frequency discharge excitation circuit with high energy transfer efficiency and corresponding matching network are determined. Through the optical wavelength meter, it can be determined that the optical path designed in this paper can guarantee the wavelength stability of 1083.207nm for a long time. By analyzing the detection signals of PD, the circularly polarized light enters the 4He cell in the light circuit designed in this paper has a higher degree of polarization. The High-Frequency discharge excitation circuit designed in this paper can light up the cell smoothly, and the input power when the circuit works stably is about 6W. Finally, the static sensitivity of the magnetometer is 5pT/Hz1/2. The 4He atom scalar magnetometer using ECDL laser designed in this paper has high static sensitivity, which basically meets the design requirements, and the instrument can be used normally in the geomagnetic environment. However, the instrument still has a lot of room for improvement, including optical path and cell performance optimization, and we will continue to study in this direction.

Beat vibration mechanism of a sluice pier under high-speed flood discharge excitation

The sluice pier prototype vibration test conducted in China Shuhe Hydropower Station shows that the vibration response of the measuring points exhibits a special form of vibration, which demonstrates intermittency and impact under high-speed flood discharge excitation. The waveform envelope increases or decreases sharply with time and shows the formation of beat vibration. Research on the mechanism of this type of vibration is rare. To analyze the characteristics and causes of the obvious beat phenomenon in the testing of the sluice pier prototype, we conduct research in the following manner. First, mathematical models of synthetic signals are built to analyze the influences of initial phase difference, frequency ratio, and amplitude ratio and determine the beat vibration formation condition. Second, the stochastic subspace identification method is used to identify the operational modal parameters (including the vibration order, frequency, damping ratio, and mode of vibration) on the basis of the measured prototype dynamic response. Last, the internal causes of the beat vibration phenomenon are analyzed based on the combination of the formation conditions of apparent beat vibration. Results show that the vibration of Shuhe sluice pier is dominated by the first two frequency components. The vibration frequency ratio is between 0.928 and 0.962 and satisfies the necessary conditions of beat vibration. The amplitude ratio is between 0.66 and 1.63 and thus makes the waveforms of beat vibration highly evident.

Investigation of Peculiarities of the Discharge Excitation with Hollow Cathode Effect in N2 in a Tube Electrode

<p>The influence of some constructive discharge system elements on the electric excitation modes and stable maintaining of pulse glow discharge plasma in N₂ in a hollow tube cathode has been investigated. The following discharge system changes have been performed: the position of a hollow electrode-cathode in the dielectric tube-holder; the method of plasma forming gas feeding to the discharge area; the distance between the electrode-cathode and counter-electrode (grounded anode). The investigation has been carried out within 50–700 Pa N₂ pressure range. The obtained results may be used in the design of gas discharge systems with hollow cathode effect.</p>

Investigation of Pulse Glow Discharge Excitation Modes in N2 in a Hollow Cylindrical Combined Cathode

Electric discharge excitation modes and N₂ pressure range for a stable formation and maintaining of pulse glow discharge plasma in a hollow combined cathode have been investigated. It has been found that both of these parameters are influenced by the constructive peculiarities of the cathode. It has been established experimentally that the value of N₂ breakdown voltage for the studied construction of the cathode within the range of 50-250 Pa does not exceed -700 V.

Speechless soma: The trauma's language in the psychosomatic

The study begins by approaching the psychological traumatism concept, recognizing it as an important precipitating of psychosomatic disorders. Based on studies of anthropologists, psychiatrists and psychoanalysts, we present trauma as a consequence of an unexpected event from where is originated intense fear, an abruption, which disorganizes and incapacitates the victim. The Institut Psychosomatique de Paris (IPSO) works with the theory that trauma is an excessive disorganization in the mental apparatus and the psychosomatic disease is the alternative that the body finds to discharge excitation, is an attempt to resolve a conflict. The psychosomatic patient is characterized by difficulty to qualify his affections, it is observed in his super adapted speech and his linear thought, which, together, differ him from neurotic and psychotic patients. Considerations about the child development and the affects qualification are made to introduce the importance of this primitive period, but we pretend to demonstrate that they are not determinants to produce psychosomatic symptoms. When the psychological pain is intense and constant, it provokes a split between mind (psyche) and body (soma) and, in the place of the elaboration and representation about the experience, explodes psychosomatic disorders.Disclosure of interestThe authors have not supplied their declaration of competing interest.

Liquid sampling-atmospheric pressure glow discharge excitation of atomic and ionic species

Inter-parametric evaluation of the production of excited atomic and ionic states in the LS-APGD microplasma is presented.