PET detector block with accurate 4D capabilities

[EN] In this contribution, large SiPM arrays (8 x 8 elements of 6 x 6 mm(2) each) are processed with an ASIC-based readout and coupled to a monolithic LYSO crystal to explore their potential use for TOF-PET applications. The aim of this work is to study the integration of this technology in the development of clinical PET systems reaching sub-300 ps coincidence resolving time (CRT). The SiPM and readout electronics have been evaluated first, using a small size 1.6 mm (6 mm height) crystal array (32 x 32 elements). All pixels were well resolved and they exhibited an energy resolution of about 20% (using Time-over-Threshold methods) for the 511 keV photons. Several parameters have been scanned to achieve the optimum readout system performance, obtaining a CRT as good as 330 +/- 5 ps FWHM. When using a black-painted monolithic block, the spatial resolution was measured to be on average 2.6 +/- 0.5 mm, without correcting for the source size. Energy resolution appears to be slightly above 20%. CRT measurements with the monolithic crystal detector were also carried out. Preliminary results as well as calibration methods specifically designed to improve timing performance, are being analyzed in the present manuscript.This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (grant agreement No 695536). It has also been supported by the Spanish Ministerio de Economia, Industria y Competitividad under Grants No. FIS2014-62341-EXP and TEC2016-79884-C2-1-R.Lamprou, E.; Aguilar -Talens, A.; Gonzalez-Montoro, A.; Monzó Ferrer, JM.; Cañizares-Ledo, G.; Iranzo-Egea, S.; Vidal San Sebastian, LF.... (2018). PET detector block with accurate 4D capabilities. Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment. 912:132-136. https://doi.org/10.1016/j.nima.2017.11.002S13213691

Results of a combined monolithic crystal and an array of ASICs controlled SiPMs

[EN] In this work we present the energy and spatial resolutions we have obtained for a γ ray detector based on a monolithic LYSO crystal coupled to an array of 256 SiPMs. Two crystal configurations of the same trapezoidal shape have been tried. In one approach all surfaces were black painted but the exit one facing the photosensor array which was polished. The other approach included a retroreflector (RR) layer coupled to the entrance face of the crystal powering the amount of transmitted light to the photosensors. Two coupling media between the scintillator and the SiPM array were used, namely direct coupling by means of optical grease and coupling through an array of light guides. Since the same operational voltage was supplied to the entire array, it was needed to equalize their gains before feeding their signals to the Data Acquisition system. Such a job was performed by means of 4 scalable Application Specific Circuits (ASICs). An energy resolution of about 24.4% has been achieved for the direct coupling with the RR layer together with a spatial resolution of approximately 2.9 mm at the detector center. With the light guides coupling the effects of image compression at the edges are significantly minimized, but worsening the energy resolution to about 33.1% with a spatial resolution nearing 4 mm at the detector center. & 2013 Elsevier B.V. All rights reserved.cknowledgments This work was supported by the Centre for Industrial Technological Development co-funded by FEDER through the Technology Fund (DREAM Project, IDI-20110718), the Spanish Plan Nacional de Investigación Científica, Desarrollo e Innovación Tecnológica (IþDþI) under Grant no. FIS2010-21216-CO2-01 and the Valencian Local Government under Grant PROMETEO 2008/114Conde Castellanos, PE.; González Martínez, AJ.; Hernández Hernández, L.; Bellido, P.; Iborra Carreres, A.; Crespo Navarro, E.; Moliner Martínez, L.... (2014). Results of a combined monolithic crystal and an array of ASICs controlled SiPMs. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 734:132-136. https://doi.org/10.1016/j.nima.2013.08.079S13213673

Simulation study of resistor networks applied to an array of 256 SiPMs

[EN] In this work we describe a procedure to reduce the number of signals detected by an array of 256 Silicon Photo-multipliers (SiPMs) using a resistor network to divide the signal charge into few readout channels. Several configurations were modeled, and the pulsed signal at the readout contacts were simulated. These simulation results were experimentally tested on a specifically designed and manufactured set of printed circuit boards. Three network configurations were modeled. The modeling provided encouraging results for all three configurations. The measurements on the prototypes constructed for this study, however, provided useful position-sensitivity for only one of the network configurations. The lack of input signal amplification into the networks, the SiPM dark current, as well as the complexity of an eight layers board with parasitic capacitances, could have caused the degradation of resolving the impact photon position. This is hard to overcome with external printed circuit boards and components.This work was supported by the Spanish Plan Nacional de Investigación Científica, Desarrollo e Innovación Tecnológica (I+D+I) under Grant FIS2010-21216-CO2-01, the Valencian Local Government under Grant PROMETEO 2008/114 and through the JAE-Predoc grant from CSIC (BOE 29/01/2010).Gonzalez, A. J., Moreno, M., Barbera, J., Conde, P., Hernandez, L., Moliner, L., . . . Benlloch, J. M. (2013). Simulation study of resistor networks applied to an array of 256 SiPMs. IEEE Transactions on Nuclear Science, 60(2), 592-598. doi:10.1109/TNS.2012.2226051S59259860

EM tomographic image reconstruction using polarvoxels

[EN] The splitting of the field of view (FOV) in polar voxels is proposed in this work in order to obtain an efficient description of a cone-beam computed tomography (CT) scanner. The proposed symmetric-polar pixelation makes it possible to deal with the 3D iterative reconstruction considering a number of projections and voxel sizes typical in CT preclinical imaging. The performance comparison, between the filtered backprojection (FBP) and 3D maximum likelihood expectation maximization (MLEM) reconstruction algorithm for CT, is presented. It is feasible to achieve the hardware spatial resolution limit with the considered pixelation. The image quality achieved with MLEM and FBP have been analyzed. The results obtained with both algorithms in clinical images have been compared too. Although the polar-symmetric pixelation is presented in the context of CT imaging, it can be applied to any other tomographic technique as long as the scan comprises the measurement of an object under several projection angles.This work was supported by the Spanish Plan Nacional de Investigaci´on Cient´ıfica, Desarrollo e Innovaci´on Tecnol´ogica (I+D+I) under Grant No. FIS2010-21216-CO2-01 and Valencian Local Government under Grants PROMETEO/2008/114, ISIC/2012/013 and APOSTD/2010/012.Soriano Asensi, A.; Rodríguez Álvarez, MJ.; Iborra Carreres, A.; Sánchez Martínez, F.; Carles Fariña, M.; Conde Castellanos, PE.; González Martínez, AJ.... (2013). EM tomographic image reconstruction using polarvoxels. Journal of Instrumentation. 8(12):1-7. https://doi.org/10.1088/1748-0221/8/01/C01004S1781

Characterization of protons accelerated from a 3 TW table-top laser system

[EN] We report on benchmark tests of a 3 TW/50 fs, table-top laser system specifically developed for proton acceleration with an intrinsic pump rate up to 100 Hz. In two series of single-shot measurements differing in pulse energy and contrast the successful operation of the diode pumped laser is demonstrated. Protons have been accelerated up to 1.6 MeV in interactions of laser pulses focused on aluminium and mylar foils between 0.8 and 25 mu m thickness. Their spectral distributions and maximum energies are consistent with former experiments under similar conditions. These results show the suitability of our system and provide a reference for studies of laser targets at high repetition rate and possible applications.This project has been funded by Centro para el Desarrollo Tecnologico Industrial (CDTI, Spain) within the INNPRONTA program, grant no. IPT-20111027, by EUROSTARS project E9113, and by the Spanish Ministry for Economy and Competitiveness within the Retos-Colaboracion 2015 initiative, ref. RTC-2015-3278-1.Bellido-Millán, PJ.; Lera, R.; Seimetz, M.; Ruiz-De La Cruz, A.; Torres Peiró, S.; Galán, M.; Mur, P.... (2017). Characterization of protons accelerated from a 3 TW table-top laser system. Journal of Instrumentation. 12:1-12. https://doi.org/10.1088/1748-0221/12/05/T05001S11212Daido, H., Nishiuchi, M., & Pirozhkov, A. S. (2012). Review of laser-driven ion sources and their applications. Reports on Progress in Physics, 75(5), 056401. doi:10.1088/0034-4885/75/5/056401Macchi, A., Borghesi, M., & Passoni, M. (2013). Ion acceleration by superintense laser-plasma interaction. Reviews of Modern Physics, 85(2), 751-793. doi:10.1103/revmodphys.85.751Ledingham, K., Bolton, P., Shikazono, N., & Ma, C.-M. (2014). Towards Laser Driven Hadron Cancer Radiotherapy: A Review of Progress. Applied Sciences, 4(3), 402-443. doi:10.3390/app4030402Kraft, S. D., Richter, C., Zeil, K., Baumann, M., Beyreuther, E., Bock, S., … Pawelke, J. (2010). Dose-dependent biological damage of tumour cells by laser-accelerated proton beams. New Journal of Physics, 12(8), 085003. doi:10.1088/1367-2630/12/8/085003Yogo, A., Sato, K., Nishikino, M., Mori, M., Teshima, T., Numasaki, H., … Daido, H. (2009). Application of laser-accelerated protons to the demonstration of DNA double-strand breaks in human cancer cells. Applied Physics Letters, 94(18), 181502. doi:10.1063/1.3126452Fritzler, S., Malka, V., Grillon, G., Rousseau, J. P., Burgy, F., Lefebvre, E., … Ledingham, K. W. D. (2003). Proton beams generated with high-intensity lasers: Applications to medical isotope production. Applied Physics Letters, 83(15), 3039-3041. doi:10.1063/1.1616661Kishimura, H., Morishita, H., Okano, Y. H., Okano, Y., Hironaka, Y., Kondo, K., … Nemoto, K. (2004). Enhanced generation of fast protons from a polymer-coated metal foil by a femtosecond intense laser field. Applied Physics Letters, 85(14), 2736-2738. doi:10.1063/1.1803915Nakamura, S., Iwashita, Y., Noda, A., Shirai, T., Tongu, H., Fukumi, A., … Wada, Y. (2006). Real-Time Optimization of Proton Production by Intense Short-Pulse Laser with Time-of-Flight Measurement. Japanese Journal of Applied Physics, 45(No. 34), L913-L916. doi:10.1143/jjap.45.l913Nishiuchi, M., Fukumi, A., Daido, H., Li, Z., Sagisaka, A., Ogura, K., … Nakamura, S. (2006). The laser proton acceleration in the strong charge separation regime. Physics Letters A, 357(4-5), 339-344. doi:10.1016/j.physleta.2006.04.053Yogo, A., Daido, H., Fukumi, A., Li, Z., Ogura, K., Sagisaka, A., … Itoh, A. (2007). Laser prepulse dependency of proton-energy distributions in ultraintense laser-foil interactions with an online time-of-flight technique. Physics of Plasmas, 14(4), 043104. doi:10.1063/1.2721066Robinson, A. P. L., Foster, P., Adams, D., Carroll, D. C., Dromey, B., Hawkes, S., … Neely, D. (2009). Spectral modification of laser-accelerated proton beams by self-generated magnetic fields. New Journal of Physics, 11(8), 083018. doi:10.1088/1367-2630/11/8/083018Nemoto, K., Maksimchuk, A., Banerjee, S., Flippo, K., Mourou, G., Umstadter, D., & Bychenkov, V. Y. (2001). Laser-triggered ion acceleration and table top isotope production. Applied Physics Letters, 78(5), 595-597. doi:10.1063/1.1343845Lee, K., Park, S. H., Cha, Y.-H., Lee, J. Y., Lee, Y. W., Yea, K.-H., & Jeong, Y. U. (2008). Generation of intense proton beams from plastic targets irradiated by an ultraintense laser pulse. Physical Review E, 78(5). doi:10.1103/physreve.78.056403Yogo, A., Daido, H., Bulanov, S. V., Nemoto, K., Oishi, Y., Nayuki, T., … Tajima, T. (2008). Laser ion acceleration via control of the near-critical density target. Physical Review E, 77(1). doi:10.1103/physreve.77.016401Lee, K., Lee, J. Y., Park, S. H., Cha, Y.-H., Lee, Y. W., Kim, K. N., & Jeong, Y. U. (2011). Dominant front-side acceleration of energetic proton beams from plastic targets irradiated by an ultraintense laser pulse. Physics of Plasmas, 18(1), 013101. doi:10.1063/1.3496058OKIHARA, S., SENTOKU, Y., SUEDA, K., SHIMIZU, S., SATO, F., MIYANAGA, N., … SAKABE, S. (2002). Energetic Proton Generation in a Thin Plastic Foil Irradiated by Intense Femtosecond Lasers. Journal of Nuclear Science and Technology, 39(1), 1-5. doi:10.1080/18811248.2002.9715150McKenna, P., Ledingham, K. W. D., Spencer, I., McCany, T., Singhal, R. P., Ziener, C., … Clark, E. L. (2002). Characterization of multiterawatt laser-solid interactions for proton acceleration. Review of Scientific Instruments, 73(12), 4176-4184. doi:10.1063/1.1516855Spencer, I., Ledingham, K. W. D., McKenna, P., McCanny, T., Singhal, R. P., Foster, P. S., … Davies, J. R. (2003). Experimental study of proton emission from 60-fs, 200-mJ high-repetition-rate tabletop-laser pulses interacting with solid targets. Physical Review E, 67(4). doi:10.1103/physreve.67.046402Kaluza, M., Schreiber, J., Santala, M. I. K., Tsakiris, G. D., Eidmann, K., Meyer-ter-Vehn, J., & Witte, K. J. (2004). Influence of the Laser Prepulse on Proton Acceleration in Thin-Foil Experiments. Physical Review Letters, 93(4). doi:10.1103/physrevlett.93.045003Ceccotti, T., Lévy, A., Popescu, H., Réau, F., D’Oliveira, P., Monot, P., … Martin, P. (2007). Proton Acceleration with High-Intensity Ultrahigh-Contrast Laser Pulses. Physical Review Letters, 99(18). doi:10.1103/physrevlett.99.185002Neely, D., Foster, P., Robinson, A., Lindau, F., Lundh, O., Persson, A., … McKenna, P. (2006). Enhanced proton beams from ultrathin targets driven by high contrast laser pulses. Applied Physics Letters, 89(2), 021502. doi:10.1063/1.2220011Steinke, S., Henig, A., Schnürer, M., Sokollik, T., Nickles, P. V., Jung, D., … Habs, D. (2010). Efficient ion acceleration by collective laser-driven electron dynamics with ultra-thin foil targets. Laser and Particle Beams, 28(1), 215-221. doi:10.1017/s0263034610000157Strickland, D., & Mourou, G. (1985). Compression of amplified chirped optical pulses. Optics Communications, 56(3), 219-221. doi:10.1016/0030-4018(85)90120-8Yogo, A., Kondo, K., Mori, M., Kiriyama, H., Ogura, K., Shimomura, T., … Bolton, P. R. (2014). Insertable pulse cleaning module with a saturable absorber pair and a compensating amplifier for high-intensity ultrashort-pulse lasers. Optics Express, 22(2), 2060. doi:10.1364/oe.22.002060Trisorio, A., Grabielle, S., Divall, M., Forget, N., & Hauri, C. P. (2012). Self-referenced spectral interferometry for ultrashort infrared pulse characterization. Optics Letters, 37(14), 2892. doi:10.1364/ol.37.002892Seimetz, M., Bellido, P., Soriano, A., Garcia Lopez, J., Jimenez-Ramos, M. C., Fernandez, B., … Benlloch, J. M. (2015). Calibration and Performance Tests of Detectors for Laser-Accelerated Protons. IEEE Transactions on Nuclear Science, 62(6), 3216-3224. doi:10.1109/tns.2015.2480682Nürnberg, F., Schollmeier, M., Brambrink, E., Blažević, A., Carroll, D. C., Flippo, K., … Roth, M. (2009). Radiochromic film imaging spectroscopy of laser-accelerated proton beams. Review of Scientific Instruments, 80(3), 033301. doi:10.1063/1.3086424Oishi, Y., Nayuki, T., Fujii, T., Takizawa, Y., Wang, X., Yamazaki, T., … Andreev, A. A. (2005). Dependence on laser intensity and pulse duration in proton acceleration by irradiation of ultrashort laser pulses on a Cu foil target. Physics of Plasmas, 12(7), 073102. doi:10.1063/1.1943436Nishiuchi, M., Daito, I., Ikegami, M., Daido, H., Mori, M., Orimo, S., … Yoshiyuki, T. (2009). Focusing and spectral enhancement of a repetition-rated, laser-driven, divergent multi-MeV proton beam using permanent quadrupole magnets. Applied Physics Letters, 94(6), 061107. doi:10.1063/1.3078291Antici, P., Fuchs, J., d’ Humières, E., Lefebvre, E., Borghesi, M., Brambrink, E., … Pépin, H. (2007). Energetic protons generated by ultrahigh contrast laser pulses interacting with ultrathin targets. Physics of Plasmas, 14(3), 030701. doi:10.1063/1.2480610Green, J. S., Carroll, D. C., Brenner, C., Dromey, B., Foster, P. S., Kar, S., … Zepf, M. (2010). Enhanced proton flux in the MeV range by defocused laser irradiation. New Journal of Physics, 12(8), 085012. doi:10.1088/1367-2630/12/8/085012Zeil, K., Kraft, S. D., Bock, S., Bussmann, M., Cowan, T. E., Kluge, T., … Schramm, U. (2010). The scaling of proton energies in ultrashort pulse laser plasma acceleration. New Journal of Physics, 12(4), 045015. doi:10.1088/1367-2630/12/4/045015Nishiuchi, M., Daido, H., Yogo, A., Orimo, S., Ogura, K., Ma, J., … Azuma, H. (2008). Efficient production of a collimated MeV proton beam from a polyimide target driven by an intense femtosecond laser pulse. Physics of Plasmas, 15(5), 053104. doi:10.1063/1.2928161Macchi, A., Sgattoni, A., Sinigardi, S., Borghesi, M., & Passoni, M. (2013). Advanced strategies for ion acceleration using high-power lasers. Plasma Physics and Controlled Fusion, 55(12), 124020. doi:10.1088/0741-3335/55/12/124020Fuchs, J., Antici, P., d’ Humières, E., Lefebvre, E., Borghesi, M., Brambrink, E., … Audebert, P. (2005). Laser-driven proton scaling laws and new paths towards energy increase. Nature Physics, 2(1), 48-54. doi:10.1038/nphys199Schwoerer, H., Pfotenhauer, S., Jäckel, O., Amthor, K.-U., Liesfeld, B., Ziegler, W., … Esirkepov, T. (2006). Laser-plasma acceleration of quasi-monoenergetic protons from microstructured targets. Nature, 439(7075), 445-448. doi:10.1038/nature04492Margarone, D., Klimo, O., Kim, I. J., Prokůpek, J., Limpouch, J., Jeong, T. M., … Korn, G. (2012). Laser-Driven Proton Acceleration Enhancement by Nanostructured Foils. Physical Review Letters, 109(23). doi:10.1103/physrevlett.109.234801Flippo, K. A., d’ Humières, E., Gaillard, S. A., Rassuchine, J., Gautier, D. C., Schollmeier, M., … Hegelich, B. M. (2008). Increased efficiency of short-pulse laser-generated proton beams from novel flat-top cone targets. Physics of Plasmas, 15(5), 056709. doi:10.1063/1.291812

Calibration and Performance Tests of Detectors for Laser-Accelerated Protons

“©2015 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.”We present the calibration and performance tests carried out with two detectors for intense proton pulses accelerated by lasers. Most of the procedures were realized with proton beams of 0.46-5.60 MeV from a tandem accelerator. One approach made use of radiochromic films, for which we calibrated the relation between optical density and energy deposition over more than three orders of magnitude. The validity of these results and of our analysis algorithms has been confirmed by controlled irradiation of film stacks and reconstruction of the total beam charge for strongly non-uniform beam profiles. For the spectral analysis of protons from repeated laser shots, we have designed an online monitor based on a plastic scintillator. The resulting signal from a photomultiplier directly measured on a fast oscilloscope is especially useful for time-of-flight applications. Variable optical filters allow for suppression of saturation and an extension of the dynamic range. With pulsed proton beams we have tested the detector response to a wide range of beam intensities from single particles 3 x 10(5) to protons per 100 ns time interval.Project funded by the Spanish Ministry of Economy and Competitiveness and co-funded with FEDER's funds within the INNPACTO 2011 program under Grant No. IPT-2011-0862-900000. This work was supported by the Spanish Plan Nacional de Investigacion Cientifica, Desarrollo e Innovacion Tecnologica (I+D+i) under Grant No. TEC 2013-48036-C3-1-R and the Valencian Local Government under Grants PROMETEOII/2013/010 and ISIC 2011/013. The work of A. J. Gonzalez is financed by CSIC with a JAE-Doc contract under Junta de Ampliacion de Estudios program, cofinanced by the European Social Fund.Seimetz, M.; Bellido, P.; Soriano Asensi, A.; García López, J.; Jiménez-Ramos, M.; Fernández, B.; Conde Castellanos, PE.... (2015). Calibration and Performance Tests of Detectors for Laser-Accelerated Protons. IEEE Transactions on Nuclear Science. 62(6):3216-3224. https://doi.org/10.1109/TNS.2015.2480682S3216322462

Diseño y primeros resultados de una cámara PET para animales pequeños basada en cristales LYSO continuos y fotomulplicadores sensibles a la posición

[ES] En este artículo presentamos el diseño de un nuevo escáner PET para animales pequeños basado en una tecnología completamente innovadora. Los resultados preliminares son muy prometedores, permitiendo obtener imágenes funcionales de alta resolución con una instrumentación compacta y de bajo coste. Los prototipos desarrollados se encuentran actualmente en pruebas en diversos centros de investigación médica, obteniéndose imá- genes de alta calidad en los campos de oncología, neurología y cardiología. Este diseño puede ser fácilmente extendido a cámaras PET dedicadas a la exploración del cerebro o de la mama. La innovación más notable de la presente tecnología consiste en el uso de un único cristal continuo por módulo, a diferencia de otras cámaras PET comerciales donde se utilizan cientos de cristales pixelados. El uso de un único cristal continuo permite abaratar el coste de fabricación, al tiempo que mejora las características de funcionamiento: resolución intrínseca en posición de 1,2 mm, resolución en energía media del 14%, resolución en la profundidad de interacción de 3 mm, sensibilidad > 4% y campo de visión transaxial de 80 mm de diámetro. En el presente artículo se describen en detalle el diseño de esta nueva cámara PET, los principios de funcionamiento, el método utilizado para su calibración y se anticipan algunas imágenes "in vivo" del miocardio y el cerebro de un ratón, permitiendo apreciar de forma preliminar la resolución y calidad alcanzadas.[EN] In this paper we present the design of a new small animal PET scanner based on a completely innovative technology. The achieved results are very promising, showing the possibility to obtain high resolution functional images with a compact and low cost scanner. Several prototypes have been developed and are currently being used at different research medical institutions. High resolution images are being obtained in application fields like oncology, neurology and cardiology. This technology can be easily applied in PET cameras for brain or breast exploration. The most significant innovation of the design is the fact of using a single crystal per module instead of hundreds of pixellated crystals as in other commercial PETs. It has the advantage of decreasing the manufacturing costs and simultaneously improves its performance: 1.2 mm position intrinsic resolution, mean energy resolution as good as 14%, 3 mm depth of interaction resolution, sensitivity above 4%, and 80 mm diameter of transaxial field of view. In this paper we describe in detail the design of this new PET camera, its principle, the calibration methodology and also some preliminary "in vivo" images of a mouse myocardium and brain, showing the achieved image resolution and qualityBenlloch Baviera, JM.; González Martínez, AJ.; Carrilero, V.; Catret, JV.; Correcher, C.; Lerche, CW.; Morera, C.... (2007). Diseño y primeros resultados de una cámara PET para animales pequeños basada en cristales LYSO continuos y fotomulplicadores sensibles a la posición. Revista de física médica. 8(2):315-321. http://hdl.handle.net/10251/79285S3153218

Innovative PET detector concept based on SiPMs and continuous crystals

The use of Silicon Photomultipliers (SiPM) has been proposed for Positron Emission Tomography (PET) readout because they are hardly affected by magnetic fields and their time response enables Time of Flight measurements. This work proposes an array of SiPM to be coupled to a monolithic LYSO crystal by means of a series of optical devices. The emitted light distribution by the scintillation crystal will be accurately determined using an Application Specific Integrated Circuit. The described sensor block aims to determine the planar coordinates and depth of interaction of the gamma ray with sub-millimetrical precision. In this work we present the initial studies regarding edge effects due to thick monolithic crystals and how to overcome these limitations by means of optical devices namely faceplates and light concentrators. We will also discuss on the alignment of such optical devices with the SiPMsGonzález Martínez, AJ.; Peiró Cloquell, A.; Sánchez Martínez, F.; Vidal San Sebastian, LF.; Benlloch Baviera, JM. (2012). Innovative PET detector concept based on SiPMs and continuous crystals. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 695:213-217. doi:10.1016/j.nima.2011.11.029S21321769

Assessment and ergonomic design of the couch for the mammograph MAMMI

[EN] The Instituto de Biomecánica (IBV) takes part in the development of a dedicated stretcher to be used with the new breast PET of the company ONCOVISION. This device called MAMMI is the clinical PET system with the highest spatial resolution in the market, specifically dedicated to breast cancer detection in early stages and its assessment in later phases. The IBV assessed ONCOVISION in the design, manufacturing, and mechanical tests of the stretcher, applying user centered design methodologies and ergonomic criteria.[ES] El Instituto de Biomecánica (IBV) participa en el desarrollo de una camilla para el nuevo mamógrafo MAMMI de la empresa ONCOVISION. El mamógrafo MAMMI es el sistema PET con mayor resolución y sensibilidad del mercado, dedicado específicamente a la detección de cáncer de mama en estadios tempranos y su valoración en fases posteriores. El IBV asesoró a la empresa ONCOVISION en las fases de diseño, fabricación y evaluación de la camilla, aplicando en su desarrollo metodologías de diseño orientado por las personas y criterios ergonómicos.El proyecto, con número de expediente IMPCND/2010/136, ha sido desarrollado en el marco de los Planes Sectoriales de Competitividad de la Empresa Valenciana, cofinanciado por el IMPIVA y el Fondo Europeo de Desarrollo Regional (FEDER) en el marco del Programa Operativo de la Comunidad Valenciana 2007-2013.Morales Martín, I.; Navarro Garcia, FJ.; López López, J.; Atienza Vicente, CM.; Solera Navarro, MJ.; González Martínez, AJ.; Caballero Ontanaya, L.... (2011). Asesoramiento y diseño ergonómico de la camilla para el mamógrafo MAMMI. Revista de biomecánica. (55):57-59. http://hdl.handle.net/10251/38792S57595

Performance study of a wide area SiPM array, ASICs controlled

In this paper, the capabilities of a wide-area gamma ray photosensor based on a SiPM array are investigated. For this purpose, we have mounted an array of 144 SiPMs with individual active area of mm and a pitch of mm, thus covering an active area of mm. Themeasurements were performed by coupling the SiPM array to LYSO crystal arrays of different pixel size (mm, mm, and mm) and 10-12 mm thicknesses. The SiPM array was controlled by means of three ASICs, and the SiPM signals were multiplexed in order to determine the gamma ray impact position by means of implementing the Anger logic algorithm in the ASIC. The optimum bias voltage and temperature dependence of the gamma ray sensor were determined. An energy resolution as good as 8%, for individual crystal pixels, were reached at 5 V overvoltage. The ASICs design allows one to "activate" different photosensor array areas. This feature has been used to evaluate the detector performance as a function of the crystal pixel size and the photosensor dark noise contribution. In this work we also show the system capability to provide depth-of-interaction (DOI) information by means of implementing a two-layer staggered approach. We have found that accurate DOI information is obtained when the ASICs enabled an SiPM active area as high as mm (SiPMs).González Martínez, AJ.; Majewski, S.; Barbera, J.; Conde Castellanos, PE.; Correcher, C.; Hernández Hernández, L.; Morera, C.... (2015). Performance study of a wide area SiPM array, ASICs controlled. IEEE Transactions on Nuclear Science. 62(1):19-26. doi:10.1109/TNS.2014.2359742192662