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Author Studen, A.; Burdette, D.; Chesi, E.; Cindro, V.; Clinthorne, N.H.; Cochran, E.; Grosicar, B.; Kagan, H.; Lacasta, C.; Linhart, V.; Mikuz, M.; Stankova, V.; Weilhammer, P.; Zontar, D.
Title Timing performance of the silicon PET insert probe Type Journal Article
Year 2010 Publication Radiation Protection Dosimetry Abbreviated Journal Radiat. Prot. Dosim.
Volume 139 Issue 1-3 Pages 199-203
Keywords (up)
Abstract Simulation indicates that PET image could be improved by upgrading a conventional ring with a probe placed close to the imaged object. In this paper, timing issues related to a PET probe using high-resistivity silicon as a detector material are addressed. The final probe will consist of several (four to eight) 1-mm thick layers of silicon detectors, segmented into 1 x 1 mm(2) pads, each pad equivalent to an independent p + nn+ diode. A proper matching of events in silicon with events of the external ring can be achieved with a good timing resolution. To estimate the timing performance, measurements were performed on a simplified model probe, consisting of a single 1-mm thick detector with 256 square pads (1.4 mm side), coupled with two VATAGP7s, application-specific integrated circuits. The detector material and electronics are the same that will be used for the final probe. The model was exposed to 511 keV annihilation photons from an Na-22 source, and a scintillator (LYSO)-PMT assembly was used as a timing reference. Results were compared with the simulation, consisting of four parts: (i) GEANT4 implemented realistic tracking of electrons excited by annihilation photon interactions in silicon, (ii) calculation of propagation of secondary ionisation (electron-hole pairs) in the sensor, (iii) estimation of the shape of the current pulse induced on surface electrodes and (iv) simulation of the first electronics stage. A very good agreement between the simulation and the measurements were found. Both indicate reliable performance of the final probe at timing windows down to 20 ns.
Address [Studen, A.; Cindro, V.; Grosicar, B.; Mikuz, M.; Zontar, D.] Jozef Stefan Inst, SI-1000 Ljubljana, Slovenia, Email: andrej.studen@ijs.si
Corporate Author Thesis
Publisher Oxford Univ Press Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0144-8420 ISBN Medium
Area Expedition Conference
Notes ISI:000277738200035 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 449
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Author Hoeschen, C.; Mattsson, S.; Cantone, M.C.; Mikuz, M.; Lacasta, C.; Ebel, G.; Clinthorne, N.; Giussani, A.
Title Minimising activity and dose with enhanced image quality by radiopharmaceutical administrations Type Journal Article
Year 2010 Publication Radiation Protection Dosimetry Abbreviated Journal Radiat. Prot. Dosim.
Volume 139 Issue 1-3 Pages 250-253
Keywords (up)
Abstract Owing to the introduction of new diagnostic procedures, such as computed tomography (CT), positron emission tomography (PET) and single photon emission computed tomography (SPECT), the individual dose caused by medical exposures has grown rapidly in the last years. This is especially a subject to radiation protection for nuclear medical diagnosis, since in this case radiopharmaceuticals are administered to the patient, meaning not only a radiation exposure to the diseased tissue but also to the healthy tissues of large parts of the body. 'Minimizing Activity and Dose with Enhanced Image quality by Radiopharmaceutical Administrations' (MADEIRA) is a project cofunded by the European Commission within the Seventh Euratom Framework Programme that aims to improve three-dimensional (3D) nuclear medical imaging technologies significantly. MADEIRA is aiming to improve the efficacy and safety of 3D PET and SPECT functional imaging by optimising the spatial resolution and the signal-to-noise ratio, improving the knowledge of the temporal variation of the radiopharmaceuticals' uptake in and clearance from tumourous and healthy tissues, and evaluation of the corresponding patient dose. Using an optimised imaging procedure that improves the information gained per unit administered dose, MADEIRA aims especially to reduce the dose to healthy tissues of the patient. In this paper, an overall summary of the current achievements will be presented.
Address [Hoeschen, C.; Giussani, A.] German Res Ctr Environm Hlth, Helmholtz Zentrum Munchen, Inst Radiat Protect, D-85764 Neuherberg, Germany, Email: christoph.hoeschen@helmholtz-muenchen.de
Corporate Author Thesis
Publisher Oxford Univ Press Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0144-8420 ISBN Medium
Area Expedition Conference
Notes ISI:000277738200045 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 450
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Author Hiti, B.; Cindro, V.; Gorisek, A.; Franks, M.; Marco-Hernandez, R.; Kramberger, G.; Mandic, I.; Mikuz, M.; Powell, S.; Steininger, H.; Vilella, E.; Zavrtanik, M.; Zhang, C.
Title Characterisation of analogue front end and time walk in CMOS active pixel sensor Type Journal Article
Year 2021 Publication Journal of Instrumentation Abbreviated Journal J. Instrum.
Volume 16 Issue 12 Pages P12020 - 12pp
Keywords (up) Charge induction; Radiation-hard detectors; Solid state detectors
Abstract In this work we investigated a method to determine time walk in an active silicon pixel sensor prototype using Edge-TCT with infrared laser charge injection. Samples were investigated before and after neutron irradiation to 5 . 10(14) n(eq)/cm(2). Threshold, noise and calibration of the analogue front end were determined with external charge injection. A spatially sensitive measurement of collected charge and time walk was carried out with Edge-TCT, showing a uniform charge collection and output delay in pixel centre. On pixel edges charge sharing was observed due to finite beam width resulting in smaller signals and larger output delay. Time walk below 25 ns was observed for charge above 2000 e(-) at a threshold above the noise level. Time walk measurement with external charge injection yielded identical results.
Address [Hiti, B.; Cindro, V.; Gorisek, A.; Kramberger, G.; Mandic, I.; Mikuz, M.; Zavrtanik, M.] Jozef Stefan Inst, Jamova Cesta 39, Ljubljana, Slovenia, Email: bojan.hiti@ijs.si
Corporate Author Thesis
Publisher IOP Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1748-0221 ISBN Medium
Area Expedition Conference
Notes WOS:000758055400055 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5138
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Author Linhart, V.; Burdette, D.; Chessi, E.; Cindro, V.; Clinthorne, N.H.; Cochran, E.; Grosicar, B.; Honscheid, K.; Kagan, H.; Lacasta, C.; Llosa, G.; Mikuz, M.; Stankova, V.; Studen, A.; Weilhammer, P.; Zontar, D.
Title Spectroscopy study of imaging devices based on silicon Pixel Array Detector coupled to VATAGP7 read-out chips Type Journal Article
Year 2011 Publication Journal of Instrumentation Abbreviated Journal J. Instrum.
Volume 6 Issue Pages C01092 - 8pp
Keywords (up) Gamma camera, SPECT, PET PET/CT, coronary CT angiography (CTA); Compton imaging
Abstract Spectroscopic and timing response studies have been conducted on a detector module consisting of a silicon Pixel Array Detector bonded on two VATAGP7 read-out chips manufactured by Gamma-Medica Ideas using laboratory gamma sources and the internal calibration facilities (the calibration system of the read-out chips). The performed tests have proven that the chips have (i) non-linear calibration curves which can be approximated by power functions, (ii) capability to measure the energy of photons with energy resolution better than 2 keV (exact range and resolution depend on experimental setup), (iii) the internal calibration facility which provides 6 out of 16 available internal calibration charges within our region of interest (spanning the Compton edge of 511 keV photons). The peaks induced by the internal calibration facility are suitable for a fit of the calibration curves. However, they are not suitable for measurements of equivalent noise charge because their full width at half maximum varies with their amplitude. These facts indicate that the VATAGP7 chips are useful and precise tools for a wide variety of spectroscopic devices. We have also explored time walk of the module and peaking time of the spectroscopy signals provided by the chips. We have observed that (iv) the time walk is caused partly by the peaking time of the signals provided by the fast shaper of the chips and partly by the timing uncertainty related to the varying position of the photon interaction, (v) the peaking time of the spectroscopy signals provided by the chips increases with increasing pulse height.
Address [Linhart, V.; Lacasta, C.; Llosa, G.; Stankova, V.] UVEG, CSIC, IFIC, Expt Phys Dept,Inst Fis Corpuscular, E-46071 Valencia, Spain, Email: Vladimir.Linhart@ific.uv.es
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1748-0221 ISBN Medium
Area Expedition Conference
Notes ISI:000291345600097 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 645
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Author Mandic, I.; Cindro, V.; Debevc, J.; Gorisek, A.; Hiti, B.; Kramberger, G.; Skomina, P.; Zavrtanik, M.; Mikuz, M.; Vilella, E.; Zhang, C.; Powell, S.; Franks, M.; Marco-Hernandez, R.; Steininger, H.
Title Study of neutron irradiation effects in Depleted CMOS detector structures Type Journal Article
Year 2022 Publication Journal of Instrumentation Abbreviated Journal J. Instrum.
Volume 17 Issue 3 Pages P03030 - 13pp
Keywords (up) Particle tracking detectors (Solid-state detectors); Si microstrip and pad detectors; Solid state detectors
Abstract In this paper the results of Edge-TCT and I-V measurements with passive test structures made in LFoundry 150 nm HV-CMOS process on p-type substrates with different initial resistivities ranging from 0.5 to 3 k Omega cm are presented. Samples were irradiated with reactor neutrons up to a fluence of 2.10(15) n(eq)/cm(2). The depletion depth was measured with Edge-TCT. The effective space charge concentration N-eff was estimated from the dependence of the depletion depth on bias voltage and studied as a function of neutron fluence. The dependence of N-eff on fluence changes with initial acceptor concentration in agreement with other measurements with p-type silicon. A long term accelerated annealing study of N-eff and detector current up to 1280 minutes at 60 degrees C was made. It was found that N-eff and current in reverse biased detector behave as expected for irradiated silicon.
Address [Mandic, I; Cindro, V; Debevc, J.; Gorisek, A.; Hiti, B.; Kramberger, G.; Skomina, P.; Zavrtanik, M.; Mikuz, M.] Jozef Stefan Inst, Jamova 39, Ljubljana, Slovenia, Email: igor.mandic@ijs.si
Corporate Author Thesis
Publisher IOP Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1748-0221 ISBN Medium
Area Expedition Conference
Notes WOS:000784713600004 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5208
Permanent link to this record