Thresholds of Etchable Track Formation and Chemical Damage Parameters in Poly(ethylene terephthalate), Bisphenol A polycarbonate, and Poly(allyl diglycol carbonate) Films at the Stopping Powers Ranging from 10 to 12,000 keV/µm

Distinct step-like changes in G values for the losses of typical functional groups in poly(ethylene terephthalate) along boron ion tracks around the detection threshold

“…As discussed in the previous work, the effective track core radius increase rapidly at the step from 0.16 nm to 0.5 nm (Yamauchi et al, 2012). With decreasing B ions energies, the discontinuous slight damage turned to be significant rapidly above 270 eV/nm, covering one repeat unit of PET in track radial direction.…”

“…Including the previously reported data for other heavy ions (Yamauchi et al, 2012), the observed trends are expressed well by the following formula against the ion fluence, F, ,…”

“…Many FT-IR spectral examinations have been performed for ion tracks in PET by several authors (Biswas et al, 1999;Liu et al, 2000;Steckenreiter et al, 1997, Zue et al, 2002. In our last study on the tracks in PET, we found the clearly different dependence of chemical damage parameters, like G values, between He and C ions on the stopping power around the detection threshold (Yamauchi et al, 2012). In this study, modified track structure along boron ions (B-10 and B-11) has been examined.…”

“…PET films with a thickness of 2.5 µm (Goodfellow, ES301025) were used to assess the G value. B ion irradiations (B-10 and B-11 ions with 6 MeV/u) were made at the medium energy irradiation room of Heavy Ion Medical Accelerator in CHIBA (HIMAC), on the stacked 50 films in which the ions stopped completely (Yamauchi et al, 2012). FT-IR measurements were carried out in vacuum both before and after the irradiations using FT/IR-6100S (JASCO, Japan), in which the entire system, including interferometer, photon detector and sample room, can be evacuated.…”

“…Carbonyl, Aromatic-ring and CH2 were clearly damaged only above the same stopping power. We have proposed a model to describe sudden increase of radiation damage that the breakings at the two most neighbor esters could be resulted in the significant losses of these functional groups (Yamauchi et al, 2012). Effects of low energy electrons around ion track have never examined well (Fromm et al, 2015).…”