الفهرس 
Radon Concentration–Track Density Calibration Factor
THEORITICAL BACKGROUNDOnly 14 pages are availabe for public view
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Abstract
The results can be summarized and for concluded as follows.
1) The structure of the cinema films has been determined by FTIR spectroscopy to be cellulose triacetate CTA or simply triacetate TAC, with chemical formula [C24H32O16]n.
2) The etching conditions of the CTA cinema film have been optimized using the same etching conditions of CR-39 [6.25N NaOH at temperature 70οC], where the optimum etching time of 45 minutes is obtained for cinema film which is much smaller than the 6 hours etching time in CR-39.
3) The calibration of the two detectors has been performed by irradiation with known radon concentrations. The variation of the track density as a function of radon concentration is found to be linear with slope of 0.173 and 0.242 for the cinema film and CR-39 respectively, showing comparable sensitivity of the two detectors to radon concentration greater than 70 pCi/l.
4) The two detectors have been tested in radioactivity field measurements at southwestern Sinai in Egypt, comparative study between CR-39 and cinema film were made in laboratory and field. The results of radon concentration and exhalation rates obtained from cinema film are in good agreement with their values obtained from CR-39.5) The calculated radon concentrations, exhalation and emanation rates deduced from the measurements of the two detectors are found to be in agreement with that obtained by El-Aassy et al., (2016) in Egypt and Hassan N. M. et al., (2009) in Hawaii and Bangladesh.
6) The activity concentrations of different radionuclides and their ratios were measured in 49 samples collected from Talet Seliem, Southwestern Sinai, Egypt by using HPGe-detector, their ratios were clues for what happened in the studied samples.
7) Thiel diagram showed that the studied area (Talet Seliem) suffered from many alteration processes which led to U-leaching and U-accumulation.
8) The relation between radon concentration, exhalation rate and radium content obtained by SSNTDs (cinema film and CR-39) and the activity concentrations of 226Ra and 238U obtained by HPGe-detector were made in laboratory and field which reflect that there are strong correlation in laboratory experiments but there are no clear relation for that in field. This difference is due to several factors that increase the probability of radon escape in the field.
9) For all calculated hazard indices, the average values are greater than the permissible world values for indices recommended by ICRP 238U is the main contributor in dose rate indicating that a great care must be ensured when dealing with such samples and hard protection precautions must be taken for workers and employees in this area.10) The size distributions of the free volumes in the two detectors have been probed using positron annihilation lifetime (PAL). No variation in the size and concentration of free volumes in CR-39 and Cinema film has been detected by PAL in the concentration range 50 – 400 pCi/l. The size distribution of free volumes in CR-39 is found to be less broad and shifted to lower free volume size compared to Cinema films. In addition, the slightly larger concentration (I3) of free volumes observed in CR-39 compared to the Cinema film could be positively correlated with the higher track density observed in CR-39.
11) According to FTIR and PAL measurements, the radon concentration in the range from 50 – 400 pCi/l did not affect the vibrational structure as well as the nano free volume hole structure of CR-39 and CTA films detectors.
12) Although Cinema films have many advantages compared with CR-39 such as, lower etching time, cost effective (recycled material), there are some disadvantages such as it contains some scratches on its surface, which makes it difficult to distinguish between different incident angles of alpha particles as well as track parameters. All tracks appear as small circles but in CR-39 there are different shapes of tracks indicating different angles of incidence. Another disadvantage of Cinema films is, due to its smaller thickness, any increase in temperature during etching process causes damage of the film.