Arief Hermanto

Determination of ion mobility in EHD flow zone of plasma generator

Determination has been carried out for ion mobility in EHD flow zone generated using a pin-concentric multiple ring electrodes and a pin-single ring electrode used as a comparator. The pin needle was made from stainless steel with a tip diameter of 0.18 mm. The concentris multiple ring electrode in form three/two concentric ring electrodes which made of metal material connected to each other. Each ring of three concentric ring electrode has a diameter of 24 mm, 16 mm and 8 mm. And each ring of two concentric ring electrode has a diameter of 24 mm and 16 mm. Single ring electrode has a diameter24 mm. The all ring has same of width and thickness were 2 mm and 3 mm. EHD was generated by using a DC high voltage of 10 kV. Pin functional as an active electrode of corona discharge while the all ring electrodes acted as ions collector and passive electrodes. The experimental results show that the ion current is proportional to V2 according to calculations by Chouelo for hyperbolic-field approach. Ion mobility obt...

Velocity Measurement of EHD Flow Produced by Pin-Multi Concentric Ring Electrodes Generator

Study of EHD flow by using generator corona discharge with electrodes configuration of pin to multi concentric rings (MCR) and pin to single ring (SR) have been curried out. We measured the velocity of EHD flow and determined the comparison of velocity of EHD flow produced by pin to single ring electrodes. The pin needle was made by stainless steel with a length of 50 mm and a tip diameter of 0.14 mm. The multi-ring electrodes constracted by three concentric rings with a metal material connected to each other and each ring has a diameter of 24 mm, 16 mm and 8 mm in width and the same ring thickness is 2 mm and 3 mm. Single ring electrode has a diameter, width and thickness respectively 24 mm , 3 mm and 2 mm. EHD was generated by using a DC high voltage of 10 kV. Pin as an active electrode of corona discharge and concentric rings multi/single ring electrodes as ions collector and passive electrodes. The velocity of EHD flow was measured by a hot-wire anemometer. We found that the velocity of EHD flow with multi-ring concentric electrodes larger than a single ring electrode. The measurement of velocity for two cases of electrodes configuration were limited at the certain voltage due to breackdown and arc phenomena. The maximum velocity of the of EHD flow using a pin-multi rings concentric was 0.7 m/s at a voltage of 6 kV.

Chirality Analysis on a Square Chiral Metamaterial

We have analyzed the chirality of terahertz (THz) wave emission from a square chiral metamaterial. The sample was manufactured with a periodic structure formed by a square pattern of chiral with different depth on a silver film. We have yield the specific polarization rotation in the THz region when the THz wave is emitted from a square chiral metamaterial. The THz emissions from these chiral metamaterials were elliptic polarization. A square chiral metamaterial was shown circular dichroism and optical activity properties at different frequencies. The ellipticity and rotation angle will reach a maximum value at a frequency of 1.2 THz and 0.6 THz, respectively. The results were indicated the possibility to controlled the polarization with chiral metamaterial structures.

Study of EHD flow generator's efficiencies utilizing pin to single ring and multi-concentric rings electrodes

EHD flow or ionic wind yield corona discharge is a stream coming from the ionized gas. EHD is generated by a strong electric field and its direction follows the electric field lines. In this study, the efficiency of the EHD flow generators utilizing pin-multi concentric rings electrodes (P-MRE) and the EHD pin-single ring electrode (P-SRE) have been measured. The comparison of efficiencies two types of the generator has been done. EHD flow was generated by using a high-voltage DC 0-10 KV on the electrode pin with a positive polarity and electrode ring/ multi-concentric rings of negative polarity. The efficiency was calculated by comparison between the mechanical power of flow to the electrical power that consumed. We obtained that the maximum efficiency of EHD flow generator utilizing pin-multi concentric rings electrodes was 0.54% and the maximum efficiency of EHD flow generator utilizing a pin-single ring electrode was 0.23%. Efficiency of EHD with P-MRE 2.34 times Efficiency of EHD with P-SRE

Terahertz Signal Measurement on a Chiral Metamaterial Using Terahertz Emission Spectroscopy

Terahertz Signal generated from chiral metamaterial due to the second order non-linear process has been observed. Chiral metamaterial used in this research have a periodic square pattern with different depth on a silver film and was fabricated by Focused Ion Beam System. Terahertz emission spectroscopy has been conducted using two amplified 100 fs laser pulses with a central wavelength of 800 nm. The emission will emerge due to an optical rectification process as a result of an intense femtosecond laser pulses radiation on a chiral metamaterial sample. The measurement result clearly shows that the terahertz signal is emitted at 2 THz frequency and sufficiently fit with a square of laser power, which is consistent with an expected optical rectification process.

The Formulation of Phonon as the Result of Second Quantization of Crystalline Lattice Vibration Using Wave Functional Method

Phonon is undoubtedly one of the most important concepts in the physics of materials. Phonon is the result when we quantize vibrational field. Whereas Schrodinger’s wave function method is the most popular and intuitive method in doing the first quantization, one usually uses Heisenberg’s operator method in the second quantization. We feel that there is a methodological and pedagogical discontinuity here. So in this paper we will use Schrodinger’s wave functional method to quantize the lattice vibration to produce phonons. Wave functional is difficult due to the nondenumerably infinite number of dimensions of its domain. In this paper we will approximate this infinity through the discrete nature of crystalline lattice so that phonon can be represented by wave function with many variables