الفهرس 
THEORITICAL ASPECTSOnly 14 pages are availabe for public view
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Abstract
This study aims to investigate some of factors affected on solid state nuclear track detectors SSNTDs using one of the most widely used types of detectors, CR-39.Initially I used irradiated CR-39 of thickness ≈ 650 µm from American Acrylics were irradiated to normal incident ions with different energy (1.89 GeV N, 0.96 GeV C, 19.2 GeV Ar, 46.48 GeV Fe, and 17.7 GeV Ni) and studied effect of aging and fading for whole five ions after twenty-seven years then I studied the effect of Successive UVA, UVB and UVC irradiation and successive etching for PADC irradiated with 17.7GeV Ni ion .
After irradiation process we began to determine the shape of ions formed on the surface of the detector using chemical etching process to make track appear we used chemical solution such as sodium hydroxide with 6.25 normality with a purity of 98% at 50 o C Temperature with different etching time starting from 6h to 96 h for aging and fading study by 6h each time and from 3h to 48h for Successive UV and successive etching study 3h each time.
We drew relation between track diameter growth with etching times for five high energy ions of N, C, Ar, Fe, and Ni measured in 1994 was compared with current ions (2021) track diameter both were etched at the same etching conditions which noted no significant differences have been observed for N, C, Ar, and Fe diameters but show increase in Ni track diameters in 2021 compared to 1994 ones.
The relation between etching rate and removed layer for whole five ions measured in2021 and those measured in 1994 was drawn and we noticed that Vb and Vt increasing for 2021 measurements.
The relation between Sensitivity and removed layer for whole five ions measured in2021 and those measured in 1994 was drawn and we noticed that V decreasing for 2021 measurements.
Then we draw two relations between relative reduction in sensitivity and removed layer and between relative depth sensitivity and removed layer relative sensitivity is calculated over the depth. PADC showed a decrease in sensitivity with depth in 1994 and reached 80% at 60 μm depth.
When we draw Sensitivity-LET relation for the five ions under investigation in the years 1994 and the corresponding ones in 2021 at different removed layers, h=10, 20, and 30 μm which shows sensitivity reduction in sensitivity is ion LET dependent. The V(LET) relation was found linear for the group of ions 1994 data at the 3 removed layers. But V(LET) relation for the same ions in the 2021 year lost its linearity.
Therefore, we suggest the following formula to calculate the PADC sensitivity at any year back, x for a given ion (LET) in terms of the current sensitivity, Vnow, and the deduced sensitivity-age reduction rate (slope) and draw PADC sensitivity as a function of the ion LET at different times, x starting from now x=0 year and back in time to x=35 year with 7 years step.
Because Ni has the most effect between the five ions so we used it to study the effect of UV with different wave lengths
We draw bulk etch rate for un-irradiated samples and 1, 2, and 3 h of UVA, UVB and UVC, respectively as a function of the etching time, te (h) and as a function with depth which shows a variation of bulk etch rate with etching time for the different UV types. So we determine relative difference between the bulk etch rate of the UV irradiated sample to the un-irradiated one which shows variation exactly in increasing the bulk etch rate with UV.
Then we draw a relation between diameters on upper side that was irradiated to UVA, UVB and UVC for 1, 2, and 3 h is compared to the average diameter of the un-irradiated side (back side) as a function of etching time also removed layer and we noticed that Diameter growth so we found relative diameter differences which showed little effect for UVA and UVB and increase in UVC.
Finally, we draw a relation between sensitivity and (etching time, removed layer) which shows decreasing in sensitivity and to determine this decreasing we calculate relative sensitivity difference.