To characterise and compare the response of EBT-XD and EBT3 radiochromic films at high doses (up to 4500 cGy) for a 175 MeV energy proton beam. EBT-XD and EBT3 film dosimeters were irradiated by a ...proton beam with 175 MeV. In order to establish dose response curves, each film piece was exposed to radiation doses 50–4500 cGy. The films were irradiated to doses of 200, 1000, 2000, and 4000 cGy and non-irradiated to determine the lateral response artifact (LRA) for varied lateral positions. The influence of film orientations (0°, 90°, and 45°) on the scanner bed was examined. Net optical density (netOD) for the films was measured at 24, 48, 72 h and 1-week post-irradiation. Digital images were created using an EPSON 11 000 XL scanner. To analyse and present our results we use: ImageJ (v. 2.0) and OriginPro 2015. The red mode netOD was lower in the EBT-XD film, with a netOD for 4500 cGy of 0.610 (EBT-XD) versus 0.893 (EBT3). The EBT-XD film presented a better lateral response than the EBT3. For films irradiated at 4000 cGy placed near the scanner edge, the differences from the central position were 17 and 16.7% (EBT3) and 10.8 and 9.1% (EBT-XD). The EBT3 film presented a satisfactory dose-response for doses <2000 cGy and would be suitable for dosimetry in standard and hypofractionated proton therapy. The EBT-XD film, however, performs better for ultra-hypofractionated proton therapy (>2000 cGy). The new EBT-XD could be a suitable dosimeter for emerging techniques, such as FLASH and Arc proton therapy.
Dry eye disease (DED) is a multifactorial ocular surface disorder characterized by loss of tear film homeostasis with associated ocular symptoms, like dryness, foreign body sensation, and ...inflammation. Numerous reports confirm an increase in dry eye symptoms after cataract surgery. DED also significantly disturbs preoperative biometric measurements, mainly by changes in keratometry measurements. The purpose of this study is to evaluate the effect of DED on biometric measurements before cataract surgery and postoperative refractive errors. PubMed database was searched for keywords: cataract surgery, dry eye disease, refractive error, refractive outcomes, keratometry, and biometry. Four clinical studies evaluating the effect of DED on refractive errors were included. In all studies, biometry was performed before and after dry eye treatment, and the mean absolute error was compared. Various substances have been used to treat dry eye, such as cyclosporin A, liftitegrast, and loteprednol. The refractive error was significantly lower after treatment in all studies. The results unanimously indicate that refractive errors can be reduced by proper treatment of DED before cataract surgery.
This paper presents the results of the proton irradiation of silicon photomulipliers (SiPMs) by mono-energetic 170 MeV protons with fluence up to 4.6\(\times\)10\(^{9}\) particles/cm\(^2\). In our ...work, three types of silicon photodetectors from Hamamatsu with areas 3\(\times\)3 mm\(^2\) and different subpixel sizes of 25\(\times\)25 \(\mu\)m\(^2\), 50\(\times\)50 \(\mu\)m\(^2\), and 75\(\times\)75 \(\mu\)m\(^2\) were used. The changes in the SiPM dark count rate (DCR) spectrum before and after irradiation in temperatures in the range of 20 \(^\circ\)C to -65 \(^\circ\)C are presented. The influence of the DCR changes on the energy resolution of the 662 keV gamma line from the \(^{137}\)Cs for a non-irradiated GAGG:Ce (1\(\%\)) scintillator is investigated. The time period of usability of the SiPM detector irradiated by protons in cosmic space was estimated.
The manufacturing technique and the main characteristics of large-volume HPGe detectors with a capacitance of ∼0.5 pF are described. Based on the developed technique, it is possible to produce a ...detector such that it is comparable in mass to a coaxial HPGe detector, but its energy resolution and detection threshold are close to the values characteristic of small X-ray HPGe detectors.
Passivation of HPGe detectors Gurov, Yu. B.; Karpukhin, V. S.; Rozov, S. V. ...
Instruments and experimental techniques (New York),
2009/1, Volume:
52, Issue:
1
Journal Article
Peer reviewed
Protective oxide coating of
p-n
junctions in HPGe detectors is investigated. Owing to this coating, HPGe detectors can be used, in particular, in liquid nitrogen environment without capsulation. A ...simple and practically feasible method for forming the protective layer by processing detectors in methanol is described. It is shown that this layer reliably protects
p-n
junctions of HPGe detectors from environmental impact. The characteristics of the protective oxide film are investigated using the Raman scattering method.
A detailed geodetic survey and, additionally, a map of slope covers have been carried out for a composite relict rock glacier on the slopes of Mt Ślęża (718 m a.s.l.), Sudetic Foreland, SW Poland. ...The survey allows one to distinguish the mobilisation, transition and accumulation zones and to define geomorphic features diagnostic for relict rock glaciers such as lateral ridges standing above a central depression, steep margins of the landforms in the transition and accumulation zones, as well as absence of distinct head scarps above. Furthermore, it indicates that the present-day hydrographic pattern on the surface of relict rock glaciers has been superimposed on the relief inherited from the active landforms. The topography indicates that tension prevailed rather than compression during the development of the rock glaciers. Some of the features, such as small lateral lobes, developed probably as a result of the compressive flow, however. The pattern of the slope cover shows that it developed during activity of the rock glaciers and been modified afterwards due to solifluction.
Segmented high-purity germanium detectors Gurov, Yu. B.; Gusev, K. N.; Katulina, S. L. ...
Instruments and experimental techniques (New York),
11/2007, Volume:
50, Issue:
6
Journal Article
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