Effects of air pressure changes on gamma linear attenuation coefficient in the air

The measurements of gamma linear attenuation coefficient in the air at variance air pressure has been done. The measurements were performed to determine the effects of air pressure changes on gamma linear attenuation coefficient in the air. The measurements were used Co-60 as the gamma radiation source and LND 72 Geiger-Muller as the radiation detector in a room with 18oC room temperature and 68% air humidity. The linear attenuation coefficient value was calculated according to Lambert-Beer law. From the measurement, we obtained the attenuated gamma intensity in the air at air pressure variation. The unattenuated gamma intensity was determined by making a linear fit function of the attenuated gamma intensity data. From the calculation, It was found that the value of gamma linear attenuation coefficient in the air increases with the increasing of air pressure.

Karakteristik Intensitas Radioaktivitas Batuan dan Sedimen Terpilih di Pantai Sedau, Kalimantan Barat

Intensitas pancaran unsur radioaktif berdasarkan data aktivitas batuan dan aktivitas pancaran ß serbuk di Pantai Sedau dilakukan menggunakan metode analisis Spektrometer Gamma dan alat cacah ß terhadap sembilan contoh sedimen dan batuan. Intensitas radioaktif batuan memperlihatkan kisaran U238 dari 0,1202 ± 0,008 Bq/25gr hingga 0,4348 ± 0,005 Bq/25gr; Th232 0,0768 ± 0,005 Bq/25gr hingga 0,4812 ± 0,015 Bq/25gr; sedangkan intensitas gross gammanya berkisar dari 1,0503 ± 0,029 Bq/25gr hingga 5,6433 ± 0,273 Bq/25gr. Semua contoh yang memiliki intensitas unsur radioaktif untuk aktivitas batuan tinggi berasal dari batuan yang sama (monzogranit), yaitu di lokasi SKP08-04. Hasil yang sama pada pancaran ß serbuknya yang memperlihatkan aktivitas ß gross tertinggi juga terjadi di lokasi SKP08-04 pada batuan monzogranit dengan intensitas paparan 0,370 ± 0,025 Bq/25gr. Berdasarkan pengamatan petrografi, monzogranit di SKP08-04 memperlihatkan pelimpahan feldspar dengan kondisi yang relatif belum teralterasi sedangkan berdasarkan analisis geokimia memperlihatkan afinitas berupa seri kalk-alkali yang tinggi potasium. The intensity of the radioactive elements based on the rock activity data and ß powder emission activity on Sedau Coast were done using Gamma Spectrometer analysis method and ß detector to the nine samples of sediment and rocks. Radioactive intensity of U238 in rocks showed a range from 0.1202 ± 0.008 Bq/ 25gr to 0.4348 ± 0.005 Bq/ 25gr; Th232 0.0768 ± 0.005 Bq/ 25gr to 0.4812 ± 0.015 Bq/ 25gr; while the gross gamma intensity ranged from 1.0503 ± 0.029 Bq/ 25gr to 5.6433 ± 0.273 Bq/25gr. All the sample that has high intensity of radioactive element, occurs in the same rock (monzogranite) which is from samples in location SKP08-04. The same results in the emission of ß powder, which showed the highest gross ß activity also occurs in the rocks monzogranite (SKP08-04) with exposure intensity was 0.370 ± 0.025 Bq/25gr. Based on petrographic observations, monzogranite in SKP08-04 showed the presence of abundant feldspar with the condition which relatively not altered, whereas the affinity based on geochemical analysis showed a calc-alkaline series of high potassium.

Zero Thickness and Reference Demarcating Method for the Deposition Detection of Corrosion Products in PWR Primary System

A nondestructive detection method based on radiation detecting technology has been design to inspect the deposition of corrosion products in Pressurized Water Reactor (PWR) Primary system. The zero thickness and reference demarcating method could measure the thickness of the corrosion products deposited inside the pipeline without the γ attenuation coefficient of the pipeline, coolant and the corrosion products which are necessary in the normal Nondestructive detection yet hard to be controlled and accurately obtained. With this method, the wall thickness and the inner diameter of the pipeline are not required during detection. The thickness of the corrosion products could be measured by only five parameters which could be monitored on-site real time: the gamma intensity at Measured Angle I, the gamma intensity at standard angle I0′, the length of the demarcating sample Z, the gamma intensity through the sample of corrosion products Ip and the gamma intensity through the sample of coolant Ic. With this method, the space distribution of the corrosion products inside the pipeline could be measured outside intuitively and conveniently. This method could also be applied to research the transport mechanisms of corrosion products in PWR Primary system, as the reference of the study on Primary water chemical.

The eclipse of CI Cygni in 1980 on the objective prism spectra

The observations of CI Cyg were carried out with the Toruń 60/90 cm Schmidt telescope with the objective prism giving a dispersion of 250 A/mm at H-gamma. Intensity traces of 20 selected spectra , made on the Kodak IIa-O plates, were made. The results were corrected for all instrumental effects and the interstellar extinction. The relative emission lines intensities have been obtained from the tracings after normalization to H-beta = 100.The spectra were typical for the quiet symbiotic star. So, all changes in the spectrum were caused by geometrical effects (eclipse).