Karakterizacija fokusne točke rendgenskog uređaja

undergraduate thesis

• Title (english): Characterization of X-ray tube focal spot
• Author: Luka Cvetko
• Mentor: Damir Markučič (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2022-09-28, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering; Production Mechanical Engineering

Abstract

Veličina fokusne točke površina je na izvoru zračenja iz kojeg se zračenje emitira. Poznavanje veličine fokusne točke i njezinih značajki ključno je za izračun geometrijske neoštrine i provodi se na nekoliko različitih načina, od kojih je devet spomenuto u ovom radu. Ideja na kojoj se temelji zadatak ovog rada bila je provjeriti i istražiti mogućnosti karakterizacije fokusne točke u smislu procjenjivanja veličine fokusne točke izračunate prethodno određenom geometrijskom neoštrinom. Geometrijska neoštrina predstavlja gubitak oštrine slike te se teži da njena vrijednost bude što je manje moguća, a samim time da i veličina fokusne točke bude što manja. U sklopu ovog rada provedene su tri metode, pri čemu je prva metoda bila ona koju se želi provjeriti, dok su druge dvije metode služile kao kontrola prvoj. Za metode dupleks i pinhole napravljene su četiri različite geometrijske postavke snimanja, dok su za treću metodu u kojoj se koristio ERESCO generator zračenja, napravljene dvije. U geometrijskim postavima su se na određene udaljenosti od slikovne ploče (filma) postavljali objekt i izvor kako bi se dobilo više izračuna u svrhu procjene veličine fokusne točke. Prva metoda koja koristi dvostruke žičane indikatore rabila se za izračun geometrijske neoštrine, nakon čega je bilo moguće procijeniti veličinu fokusne točke. Manjom modifikacijom ove metode dobiveni rezultati bili su precizniji od onih propisanih normom.

Abstract (english)

A focal spot size is an area on the source of radiation from which radiation is emitted. Determination of the focal spot size, as well as her characteristics, is crucial for determination of geometric unsharpness and it is done in several different ways, from which nine are mentioned in this paper. The idea on which this paper is based on was to check and explore the possibilities of characterization of focal spot in terms of estimating the size of the focal spot calculated by previously determined geometric unsharpness. Geometric unsharpness represents loss of image sharpness and the aim is to make its value as small as possible, and therefore also minimalize the focal spot size. As part of this work three methods were used, whereby the first one was the one that wants to be implemented, while the other two methods were used as supervision for the first method. For duplex and pinhole methods, four different geometric setups were done, while for the third one that uses ERESCO x-ray generator, only two were made. In those setups, distances from an object to a source and from the object to a film were being set at the certain values to get more calculations for assessment purposes. The primary method, that uses duplex indicators, was used to calculate geometric unsharpnes, after which it was possible to assess the value of the focal spot size. With small modification of this method, received results were more precise than those prescribed by the norm.

• Keywords: geometrijska neoštrina; veličina fokusne točke; metoda
• Keywords (english): geometric unsharpness; focal spot size; method
• Language: croatian
• URN:NBN: urn:nbn:hr:235:471897
• Study programme: Title: Mechanical Engineering; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka strojarstva (sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka strojarstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2022-09-24 16:25:34