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K. Sofjan Firduasi
Laboratorium Optoelektronik dan Laser, Jurusan Fisika FMIPA UNDIP
Physics

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Journal : BERKALA FISIKA

 1 
Sudut Putar Jenis Elektrooptis pada Bensin dan Spiritus Riyani, Riyani; Marhaendrajaya, Indras; Firduasi, K. Sofjan
BERKALA FISIKA Vol 11, No 1 (2008): Berkala Fisika
Publisher : BERKALA FISIKA

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Abstract

In this paper, we measured the specific electro optic rotary power h of petroleum and spiritus solution in static external electric field Eex using Kerr Effect. The magnitude field to induce the samples is produced by two parallel plates (3 ´ 4 cm2) applied on varied DC high voltage 0-10 kV. Variation of NaCl solution is held on 5%, 10%, until 35%. The light source used to observe change of polarization angle is diode pointer laser 654 nm in wavelength. From the result of experiment we obtained that theh’s value of petrol is (0.1040.008) o/V and for spiritus is (0.0660.006) o/V, indicates that Petrol optics more active than spiritus one.   Key words: non-linear optics, external electrics field, specific electro optic rotary power
Studi Efek Kerr Untuk Pengujian Tingkat Kemurnian Aquades, Air PAM dan Air Sumur Sukarsono, Kristantyo; Marhaendrajaya, Indras; Firduasi, K. Sofjan
BERKALA FISIKA Vol 11, No 1 (2008): Berkala Fisika
Publisher : BERKALA FISIKA

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In this research was discussed about the ratio of purity level of aquades, running water, and well water by using the Kerr effect. Several substances being used are sugar solutions with the concentration of 10%, 20%, 30%, 40% and 50% for linearity testing, salt solutions with the concentration of 10%, 30% and 50% for the testing of ionic response which be infested by some dipoles of H2O molecules in the salt solution toward the external electrical field, and also aquades, running water and well water as the water samples having the different purity. The external electrical field being given in the substances from zero to 9×105 V/m and awakened by conducting the direct current of electric on the parallel plates. A light beam being used is a diode laser with λ = 645 nm. The result of research was showing that the presence of external electrical field causing the difference of polarization angle indicating the purity level of water kinds since influenced by ions in the water. Based on the ions containing in it have been known that the value of aquades purity is 4 ppm, the value of running water purity is 108 ppm and the value of well water purity is 190 ppm. So, aquades is purer than running water and running water is purer than well water. The average value of polarization angle of aquades, running water, and well water is approximately 0,50º, 0.25º and -0,25º respectively. Key words: Kerr Effect, electrical field, polarization angle
OPTIMASI SHIELDING NEUTRON PADA THERMALIZING COLUMN REAKTOR KARTINI Nurlaili, Fidayati; Azam, M.; Firduasi, K. Sofjan; Widarto, Widarto
BERKALA FISIKA Vol 11, No 4 (2008): Berkala Fisika
Publisher : BERKALA FISIKA

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Abstract

Shield optimization and the calculation of neutron flux the coming out of the thermalizing column of the Kartini reactor have been conducted.The neutron flux will decrease exponentially as it passes the thermalizing column. The thermalizing column of Kartini reactor consists of many different kinds of shields, i.e, graphite, lead, paraffin and an empty chamber of air, therefore the neutron flux count that is coming out of the thermalizing column can be calculated and the shields within the column can be optimized to give smaller  neutron flux.Calculation result indicates that the neutron flux coming out of the thermalizing column is 2,681×10-11 cacah cm-2s-1. After optimization, the remaining flux coming out of the thermalizing column is 1,042×10-28cacah cm-2s-1. Key words: thermalizing column, Shield, neutron flux
Review Studi Difraksi Fresnel Menggunakan Celah Bentuk Lingkaran Rosyidah, Arinar; Marhaendrajaya, Indras; Firduasi, K. Sofjan
BERKALA FISIKA Vol 11, No 2 (2008): Berkala Fisika
Publisher : BERKALA FISIKA

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Abstract

The Fresnel Diffraction has been reviewed to measure the wavelenght of monochromatic light sources. The change of circle fringe’s number is obtained by the change of the distance between source and slits, and the change of fringe’s radius. We used here the diode green pointer laser and red pointer laser as light sources with 1 mW in power. From the measurement, we obtained that the wavelenght of green laser and red pointer laser are still in the range of literature values. Key words: Fresnel diffraction, Fresnel zone.
Co-Authors Arinar Rosyidah Fidayati Nurlaili Indras Marhaendrajaya Kristantyo Sukarsono Muchammad Azam, Muchammad Riyani Riyani Widarto Widarto