scholarly journals ANALOG COMPUTER FOR STUDYING DIATOMIC MOLECULAR SPECTRA IN TERAHERTZ FREQUENCY

2018 ◽  
Vol 3 (2) ◽  
pp. 117-126
Author(s):  
Usman Malik ◽  
Muhamad Hamdi ◽  
Salomo Salomo
Keyword(s):  
Diatomic Molecule ◽  
Energy Levels ◽  
Rotational Constant ◽  
Analog Computer ◽  
Spectral Lines ◽  
Radiation Absorption ◽  
Thz Radiation ◽  
Molecular Spectra ◽  
Rigid Rotator ◽  
Line Intensities

This paper introduces a harmonic oscillator model for rovibronic terahertz spectrum of a model of a rigid diatomic rotor with some control parameters. The model shows a study of rotationally-resolved terahertz band spectra of the vibrational transition in diatomic molecules. THz radiation absorption is used as a closed-form system known as the analog computer dynamics mode. The optical terahertz region spectrum of the diatomic molecule consists of a series of lines. Their separations are not exactly constant. A diatomic molecule is not truly a rigid rotator, because it simultaneously vibrates with a small amplitude. Due to quantized vibrational and rotational energy levels and the selection rules, allowed transitions result in a highly ordered spectrum consisting of a P branch separated by a central gap. Adjacent spectral lines are separated by a spacing of 2B, and since line intensities depend on Boltzmann factor for thermal population and quantum number J, each branch monotonically increases and decreases. As temperature increases, more lines are observed, and line intensities decrease due to the population being spread over more rotational levels. Interactivity research also involves on effects of the fundamental vibrational frequency, rotational constant B and temperature included line width on the observed spectrum.

scholarly journals FEM Simulation of Frequency-Selective Surface Based on Thermoelectric Bi-Sb Thin Films for THz Detection

Photonics ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 119
Author(s):  
Anastasiia Tukmakova ◽  
Ivan Tkhorzhevskiy ◽  
Artyom Sedinin ◽  
Aleksei Asach ◽  
Anna Novotelnova ◽  
...  
Keyword(s):  
Thin Films ◽  
Response Times ◽  
Fem Simulation ◽  
Film Surface ◽  
Frequency Selective Surface ◽  
Fast Response ◽  
Radiation Absorption ◽  
Thz Radiation ◽  
Frequency Filter ◽  
Frequency Selective

Terahertz (THz) filters and detectors can find a wide application in such fields as: sensing, imaging, security systems, medicine, wireless connection, and detection of substances. Thermoelectric materials are promising basis for THz detectors’ development due to their sensitivity to the THz radiation, possibility to be heated under the THz radiation and produce voltage due to Seebeck effect. Thermoelectric thin films of Bi-Sb solid solutions are semimetals/semiconductors with the band gap comparable with THz energy and with high thermoelectric conversion efficiency at room temperature. Detecting film surface can be transformed into a periodic frequency selective surface (FSS) that can operate as a frequency filter and increases the absorption of THz radiation. We report for the first time about the simulation of THz detector based on thermoelectric Bi-Sb thin-filmed frequency-selective surface. We show that such structure can be both detector and frequency filter. Moreover, it was shown that FSS design increases not only a heating due to absorption but a temperature gradient in Bi-Sb film by two orders of magnitude in comparison with continuous films. Local temperature gradients can reach the values of the order of 100 K·mm−1. That opens new perspectives for thin-filmed thermoelectric detectors’ efficiency increase. Temperature difference formed due to THz radiation absorption can reach values on the order of 1 degree. Frequency-transient calculations show the power dependence of film temperature on time with characteristic saturation at times around several ms. That points to the perspective of reaching fast response times on such structures.

scholarly journals Study of opacity broadening in spectral lines for helium like ions in aluminum plasma which produced by laser

2011 ◽  
Vol 8 (1) ◽  
pp. 54-58
Author(s):  
Baghdad Science Journal
Keyword(s):  
Theoretical Analysis ◽  
Spectral Line ◽  
Quantum Number ◽  
Plasma Density ◽  
Energy Levels ◽  
Spectral Lines ◽  
Aluminum Plasma

A theoretical analysis studied was performed to study the opacity broadening of spectral lines emitted from aluminum plasma produced by Nd-YLF laser. The plasma density was in the range 1028-1026 )) m-3 with length of plasma about ?300) m) , the opacity was studied as function of plasma density & principle quantum number. The results show that the opacity broadening increases as plasma density increases & decreases with the spacing between energy levels of emission spectral line.

scholarly journals Excitation of Spectra of Multiply Ionized Atoms by Capacitor Discharges

1974 ◽  
Vol 28 (3) ◽  
pp. 223-234 ◽  
Author(s):  
Cornelius H. H. Van Deurzen ◽  
John G. Conway
Keyword(s):  
Differential Equation ◽  
Electrical Circuit ◽  
Spectral Lines ◽  
Circuit Parameter ◽  
Excitation Energies ◽  
Time Resolved ◽  
Transfer Rates ◽  
Line Intensities ◽  
Relative Line ◽  
Varied Intensity

Spectra of vanadium have been produced in a vacuum sliding spark, and their relative line intensities have been measured as parameters of the electrical circuit were varied. Intensity maxima of the spectral lines are interpreted as representing excitation energies and have been found to depend in a definitive manner on the power delivered to the source and on the duration of the discharge. The differential equation of the circuit is solved for the charge and energy transfer rates from the capacitor to the source, and two functions of the continuous circuit parameter [Formula: see text] are defined which greatly assist in interpreting the effect of the circuit parameters on the excitation in the source. A relationship was found between the excitation in the source and the electrical circuit parameters. By means of this relationship one may obtain a good estimate of the excitation gained in the spark source. It is shown that by exercising careful control over the circuit parameters it is possible to separate spectra of neighboring ionization stages through either total pulse or time-resolved observations.

Approximate analytical solution of continuous states for the l-wave Schrödinger equation with a diatomic molecule potential

Open Physics ◽  
2010 ◽  
Vol 8 (4) ◽  
Author(s):  
Gao-Feng Wei ◽  
Wen-Chao Qiang ◽  
Wen-Li Chen
Keyword(s):  
Schrödinger Equation ◽  
Diatomic Molecule ◽  
Schrodinger Equation ◽  
Scattering Amplitude ◽  
Energy Levels ◽  
Bound State ◽  
Radial Wave ◽  
Continuous States ◽  
Analytical Properties ◽  
Function Potential

AbstractThe continuous states of the l-wave Schrödinger equation for the diatomic molecule represented by the hyperbolical function potential are carried out by a proper approximation scheme to the centrifugal term. The normalized analytical radial wave functions of the l-wave Schrödinger equation for the hyperbolical function potential are presented and the corresponding calculation formula of phase shifts is derived. Also, we interestingly obtain the corresponding bound state energy levels by analyzing analytical properties of scattering amplitude.

DERIVATIVES OF MONOGERMANE: PART I. THE VIBRATION–ROTATION SPECTRA OF GERMYL FLUORIDE AND BROMIDE

1962 ◽  
Vol 40 (4) ◽  
pp. 579-589 ◽  
Author(s):  
J. E. Griffiths ◽  
T. N. Srivastava ◽  
M. Onyszchuk
Keyword(s):  
Harmonic Oscillator ◽  
Infrared Absorption ◽  
Thermodynamic Functions ◽  
Low Frequency ◽  
Rotational Constant ◽  
Rigid Rotator ◽  
Harmonic Oscillator Model ◽  
Infrared Absorption Spectra ◽  
Vibration Rotation ◽  
Derivatives Of

The vibration–rotation infrared absorption spectra of germyl fluoride and bromide have been observed. All of the fundamentals in GeH3F were located, and the rotational structure of the E-type bands were resolved and analyzed. The low-frequency band, ν3(a1), in GeH3Br was not observed but an estimate of its position was made from the frequencies of the combination band ν3 + ν6 and of ν6. The rotational constant A″ and the Coriolis constants ζ4, ζ5, and ζ6 were calculated for both molecules, and agreement with microwave A″ values was satisfactory. Thermodynamic functions based upon a rigid-rotator, harmonic-oscillator model have been evaluated for germyl fluoride and bromide.

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