[en] Staining method in mineral identification process is based on stains effect on mineral by certain chemical solution. K feldspar stains are characteristically yellow colour, plagioclase is pink or red, cardierite is deep red and muscovite is yellowish, but paragonite is unstained. Sometimes stains depend on rock condition and minerals position on thin section. Furthermore it can be developed to petrofabric studies. (author)

[en] The design and construction of scanning horn for electron beam machine has been done. In electron beam machine, the electron beam pass through scanning horn. Therefore, the scanning horn must be evacuated up to 10"-"6 mbar. The objective of the design is to determine of the type and the dimension of material for construction of scanning horn so that there is no deflection during evacuation. The result of design and construction is the drawing of the structure of scanning horn and the detail construction of parts of the scanning horn for electron beam machine. The design result the material for scanning horn of stainless steel 316 L in order that deflection is lower than 4 mm. The scanning horn use strip from 12 pieces of stainless steel 316 L of 10 mm thick. In the construction, thick of the 7"t"h up to 12"t"h strip is 20 mm. The test result show that the maximum deflection is 1 mm occurred at the 5"t"h and 10"t"h strip. The ultimate pressure using rotary pump is 5×10"-"1 mbar (there is still a leakage) and is 6.6×10"-"2 mbar (no more leakage). When a leakage is occur the ultimate pressure test can not be carried out using diffusion pump. But after reparation so that there is no more leakage, the ultimate pressure test using diffusion pump can be carried out and yield 5×10"-"4 mbar ultimate pressure. The ultimate pressure using rotary and diffusion pumps is approach the capability of the rotary and diffusion pumps used. (author)

[en] Nitriding with plasma/ion nitriding technique for surface treatment of AISI 304 and low carbon steel as a machine component material has been done. Surface treatment is meant to improve the surface quality of metal especially its hardness. To reach the optimum condition it has been done a variation of nitriding pressure, while to analyse the result it has been done the hardness and microstructure test, and the nitrogen content. Result of the test indicates that: the optimum hardness obtained at 1.8 mbar of pressure that is 624.9 VHN or 2.98 times while the initial hardness is 210.3 VHN for AISI 304 and 581.6 VHN or 3.07 times compare with initial hardness 142.9 VHN for low carbon steel. The thickness of nitride layer for AISI 304 and low carbon steel is around 30 µm. Nitrogen contents after nitriding are 10.74% mass or 30.32% atom for AISI 304 and 6.81% mass or 21.76% atom for low carbon steel. (author)

[en] Generally, an expired structure aluminum is recycled into raw materials for the next casting process or component products. Slag and aluminum left in the ladle caused low melting efficiency. Microstructure formed in the castings components solidification process is often used to control mechanical properties and the castings fabrication. The purpose of this study is to improve structure aluminum recycling process quality. This recycling study used structure aluminum raw materials with recycling levels variations in the 1st, 2nd, 3rd, and 4th. In the first recycling, the structure aluminum pieces as melting raw materials weighing 2 kg were put in the induction furnace for melting. Let the aluminum pieces melted in the furnace and the temperature continued to rise to 700°C. Next, separated and took the floating slag on top of liquid aluminum, lifted the ladle from the furnace and poured the aluminum in the ingot mold from the permanent mold. After the ingots in the mold were being frozen and cooled, removed the ingots from the mold to be weighed and tested for microstructure. In the second recycling, the melted raw material was the first recycling ingot with the same procedure. In the third recycle, the melted raw material was the second recycling ingot with the same procedure; and the third recycling, the raw material that was melted was the third recycling ingot with the same procedure. Then the slag and ingot was weighed, and microstructure photos from the ingots were taken. From the microstructural photographs results, a calculation process can be performed to determine the grain size of each specimen. For smelting efficiency testing results at each recycling stages respectively 1st, 2nd, 3rd, and 4th were 76.23%, 82.64%, 85.17%, and 89.55%. The largest microstructure diameter at the first recycling for the surface part was 42,512 µm and the center was 43,314 µm. The smallest grain diameter of the 3rd recycling for the surface part was 42,164 µm and the center was 42,346 µm. (paper)

[en] A design of power oscillator for Cockroft-Walton high voltage supply was carried out. This high voltage supply would be used as the acceleration voltage supply of an electron beam machine designed to have 500 keV/20 mA capacity. The power oscillator design consisted of output specification, circuit diagram, power supply and oscillator main components determinations. The power oscillator output wave power, voltage and frequency designed according to voltage multiplier input requirements. The design results showed that the circuit was class-c tickler oscillator having an output specification of 12.1 kW, 15 kV and 40 kHz sinus wave. The main component was a ITK 15-2 triode tube. (author)

[en] A simplified review on electron transport in a random system is presented, using donor band in semiconductors as an example. Anderson metal to non metal transition occurs when the random energy fluctuation is large when compared to the donor band width. After Anderson localization electron transport can still occur by phonon assisted variable range hopping which gives 1nzeta./.(1/T)sup(1/4). Simulation of a strong magnetic can be achieved by using semiconductors with low effective mass and high dielectric constant. Such a field can induce Anderson transition and produce variable range hopping conductivity in the form of 1nzeta./.(1/fT)sup(2/5), where f is a function ofthe field strength. Comparison is made with conductivity data of n-type Insb at very low temperatures. (author)

[en] The construction and the characterization of glow-discharge plasma for hydrogenization of amorphous silicon thin film have been done. The glow-discharge plasma was produced in the plasma tube by the radio-frequency source. The glow-discharge plasma tube was made from pyrex glass with 15 cm diameter and 25 cm length. The main component of the radio-frequency source was tetrode tube of QB 3/300 type, and operated at 13,56 MHz frequency. The characterization of rf glow discharge plasma system was done by determination of plasma tube temperature and plasma characteristic, i.e. temperature and density of plasma under the variation of gas pressure in the plasma tube. The results of these measurement and from the calculation show that the temperature of plasma tube which can be reduced by the heat radiation shield was 35^oC at the heater temperature of 290^oC. The optimum plasma density at 0.2 torr gas pressure was 16.46.10⁸ cm^-3 and the plasma temperature was 45.4 eV. By this results the system of glow-discharge plasma for hidrogenization of a-Si thin film was completed

[en] Fabrication Of Side-Window Type Geiger Muller Detector With Argon, Alcohol And Bromine As Filling Gases. Fabrication of side window type Geiger Muller detector has been conducted with argon as the main filling, alcohol and bromine as quenching gas. The Geiger Muller detector tube is made of stainless steel with diameter of tube is 16 mm, anode is made of tungsten wire with 0,08 mm in diameter and the length of active media is 100 mm. The pressure of argon and alcohol as filling gas were varied such as 8,75 : 1,25; 9 : 1 ; and 9,5 : 0,5 cm Hg. respectively, while the ratio of pressure between argon and bromine is 20:0,2 cm Hg. The test result shows that the ratio between argon and alcohol is 9 :1, the length of plateau is 180 volt, slope is 9,60 %/100 volt, resolving time is 6,725 × 10⁶ seconds and operating voltage is 1160 volts. Meanwhile, halogen gas (bromine) as quenching in the ratio of 20 : 0,2 cm Hg, the length of plateau is 70 volts, the slope is 42,32 %/100 volt, the resolving time τ = 1,89 × 10⁶ seconds and operating voltage is 650 volts. In this research, the detector lifetime is still unpredictable because during the process of process of test, the detector still had a long plateau and the pulse shape has not discharged. The number of counting resulted from the detector with argon and alcohol as filling gas is 3,105 × 10⁶ count, while for argon and bromine is 1,96597 × 10⁶ count. (author)

[en] The simulation of electron beam trajectory for electron gun of electron beam machine has been done. The simulation is carried out according to mechanical design of the electron gun. The simulation is carried out by using the software made by Andrzej Soltan Institute for Nuclear Studies, Swierk-Poland. The result obtained from simulation is approximately parallel electron beam trajectory of 20 mA beam current at 0.66 kV anode voltage, 15 mm cathode-anode distance and 67.5^o cathode angle. Arrangement of electron gun and accelerating tube with 15 kV voltage between anode and the first electrode of accelerating tube yields focus distance of 34 mm from the to cathode. To obtain the approximately parallel beam trajectory which has -0.03^o entrance angles to accelerating tube, the suitable cathode-anode voltage is 12.66 kV. With the entrance angle of -0.03^o it is expected that the electron beam can be accelerated and the beam profile has a small divergence after passing the accelerating tube. (author)

[en] The construction and testing of window system of 350 keV/10 mA electron beam machine have been carried out. The function of the window is to separate vacuum chamber of electron beam machine from atmosphere and pass the electron beam from electron gun to the target. The design of window system consist of scanning horn flange, intermediate flange, supporting flange, gasket holder, made of pure aluminium wire material and cooling nozzle. To obtain high vacuum, the pure aluminium wire gasket should be used. But in vacuum testing the pure aluminium wire gasket was replaced with viton and titanium foil window of 50 μm was replaced with bronze plate. Theoretically the loss of energy of 500 keV electron beam at window is 33.32 keV. So that the 20 mA electron beam current will produce power dissipation of 665.2 Watt. For cooling the power dissipation the air speed of 41.553 m/sec is blown to the window surface. Blower with capacity of 0.167 m³/sec was used in this experiment, so that the nozzle around of 3.35 mm is applied. The result of test indicates that the optimal vacuum 5x10^-5 mbar was reached, this result was close to the used diffusion pump capacity that is 3.5x10^-5 mbar. It can be concluded that there is no leakage on the window construction. (author)