Entropy as a measure of the performance of phosphors used in medical imaging radiation detectors

dc.contributor.author	Κάβουρας, Διονύσης Α.	el
dc.contributor.author	Κανδαράκης, Ιωάννης Σ.	el
dc.contributor.author	Μαρής, Θωμάς	el
dc.contributor.author	Παναγιωτάκης, Γεώργιος Σ.	el
dc.contributor.author	Νομικός, Κωνσταντίνος Δ.	el
dc.date.accessioned	2015-05-05T11:41:25Z
dc.date.available	2015-05-05T11:41:25Z
dc.date.issued	2015-05-05
dc.identifier.uri	http://hdl.handle.net/11400/9736
dc.rights	Αναφορά Δημιουργού-Μη Εμπορική Χρήση-Όχι Παράγωγα Έργα 3.0 Ηνωμένες Πολιτείες	*
dc.rights.uri	http://creativecommons.org/licenses/by-nc-nd/3.0/us/	*
dc.source	http://link.springer.com/article/10.1007/s003390000538	en
dc.subject	PACS: 78.65
dc.subject	42.80
dc.subject	Phosphors
dc.subject	Entropy
dc.subject	Φωσφορίζουσες
dc.subject	Εντροπία
dc.title	Entropy as a measure of the performance of phosphors used in medical imaging radiation detectors	en
heal.type	journalArticle
heal.classification	Medicine
heal.classification	Physics
heal.classification	Ιατρική
heal.classification	Φυσική
heal.classificationURI	http://id.loc.gov/authorities/subjects/sh00006614
heal.classificationURI	http://skos.um.es/unescothes/C02994
heal.classificationURI	N/A-Ιατρική
heal.classificationURI	N/A-Φυσική
heal.keywordURI	http://id.loc.gov/authorities/subjects/sh85101117
heal.keywordURI	http://id.loc.gov/authorities/subjects/sh85044150
heal.identifier.secondary	DOI 10.1007/s003390000538
heal.language	en
heal.access	campus
heal.recordProvider	Τ.Ε.Ι. Αθήνας. Σχολή Τεχνολογικών Εφαρμογών. Τμήμα Μηχανικών Βιοϊατρικής Τεχνολογίας Τ.Ε.	el
heal.publicationDate	2001
heal.bibliographicCitation	Cavouras, D., Kandarakis, I., Maris, T., Panayiotakis, G. and Nomicos, C. (January 2001). Entropy as a measure of the performance of phosphors used in medical imaging radiation detectors. Applied Physics A. 72(1). pp. 67-72. Springer-Verlag: 2001. Available from: http://link.springer.com/article/10.1007/s003390000538	en
heal.abstract	In information theory, entropy expresses the information gain obtained after detection of a signal concerning the state of a parameter of interest. In this study, entropy has been expressed in terms of physical quantities (emitted optical fluence and MTF) related to the imaging performance of phosphor materials, which are employed in medical imaging radiation detectors. Four phosphor materials, used in the form of laboratory-prepared fluorescent layers (screens), were compared on the basis of their entropy performance. Measurements were performed using 30- and 80-kVp X-ray beams often employed in X-ray imaging. Results showed that phosphor materials with high density and effective atomic number exhibit high entropy performance, especially at the higher X-ray tube voltage of 80 kVp. Entropy values are also affected by the type of activator, which determines the intrinsic X-ray-to-light conversion efficiency, and the spectrum of emitted light. The proximity of the incident X-ray quanta energy to the energy of the K-shell threshold for photoelectric absorption is an additional important factor which increases entropy. This effect was more apparent in the performance of yttrium-based phosphors at the lower voltage of 30 kVp.	en
heal.publisher	Springer-Verlag	en
heal.journalName	Applied Physics A	en
heal.journalType	peer-reviewed
heal.fullTextAvailability	true