A Smart Pixel Camera for future Cherenkov Telescopes

The Smart Pixel Camera is a new camera for imaging atmospheric Cherenkov telescopes, suited for a next generation of large multi-telescope ground based gamma-ray observatories. The design of the camera foresees all electronics needed to process the images to be located inside the camera body at the focal plane. The camera has a modular design and is scalable in the number of pixels. The camera electronics provides the performance needed for the next generation instruments, like short signal integration time, topological trigger and short trigger gate, and at the same time the design is optimized to minimize the cost per channel. In addition new features are implemented, like the measurement of the arrival time of light pulses in the pixels on the few hundred psec timescale. The buffered readout system of the camera allows to take images at sustained rates of O(10 kHz) with a dead-time of only about 0.8 % per kHz.Comment: 8 pages, 5 figures; to appear in the proceedings of "Towards a Network of Atmospheric Cherenkov Detectors VII", 2005, Palaiseau, Franc

A Single-Particle Trigger for Time-of-Flight Measurements in Prompt-Gamma Imaging

[EN] Tracking of single particles accelerated by synchrotrons is a subject that crosses several physics fields. The high clinical intensities used in particle therapy that can exceed 10(9)p/s make this task very challenging. The tracking of the arrival time of single particles in the ion beam is fundamental for the verification of the particle range and dose delivered to the patient. We present a prototype made of scintillating fibers which has been used to provide time-of-flight (TOF) information for three beam species currently accelerated at the Heidelberg Ion-Beam Therapy Center (HIT). We have demonstrated a time-tracker for a prompt-gamma spectroscopy system that allows for a background TOF rejection with a sub-nanosecond time resolution.PM was supported by a research fellowship for postdoctoral researchers from the Alexander von Humboldt Foundation, Bonn, Germany. RD was supported by the International Max Planck Research School for Quantum Dynamics in Physics, Chemistry and Biology, Heidelberg, Germany.Martins, PM.; Dal Bello, R.; Seimetz, M.; Hermann, G.; Kihm, T.; Seco, J. (2020). A Single-Particle Trigger for Time-of-Flight Measurements in Prompt-Gamma Imaging. Frontiers in Physics. 8:1-13. https://doi.org/10.3389/fphy.2020.00169S1138Parodi, K., Crespo, P., Eickhoff, H., Haberer, T., Pawelke, J., Schardt, D., & Enghardt, W. (2005). Random coincidences during in-beam PET measurements at microbunched therapeutic ion beams. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 545(1-2), 446-458. doi:10.1016/j.nima.2005.02.002Crespo, P., Barthel, T., Frais-Kolbl, H., Griesmayer, E., Heidel, K., Parodi, K., … Enghardt, W. (2005). Suppression of random coincidences during in-beam PET measurements at ion beam radiotherapy facilities. IEEE Transactions on Nuclear Science, 52(4), 980-987. doi:10.1109/tns.2005.852637Testa, E., Bajard, M., Chevallier, M., Dauvergne, D., Le Foulher, F., Freud, N., … Testa, M. (2008). Monitoring the Bragg peak location of 73MeV∕u carbon ions by means of prompt γ-ray measurements. Applied Physics Letters, 93(9), 093506. doi:10.1063/1.2975841Biegun, A. K., Seravalli, E., Lopes, P. C., Rinaldi, I., Pinto, M., Oxley, D. C., … Schaart, D. R. (2012). Time-of-flight neutron rejection to improve prompt gamma imaging for proton range verification: a simulation study. Physics in Medicine and Biology, 57(20), 6429-6444. doi:10.1088/0031-9155/57/20/6429Smeets, J., Roellinghoff, F., Prieels, D., Stichelbaut, F., Benilov, A., Busca, P., … Dubus, A. (2012). Prompt gamma imaging with a slit camera for real-time range control in proton therapy. Physics in Medicine and Biology, 57(11), 3371-3405. doi:10.1088/0031-9155/57/11/3371Verburg, J. M., Riley, K., Bortfeld, T., & Seco, J. (2013). Energy- and time-resolved detection of prompt gamma-rays for proton range verification. Physics in Medicine and Biology, 58(20), L37-L49. doi:10.1088/0031-9155/58/20/l37Golnik, C., Hueso-González, F., Müller, A., Dendooven, P., Enghardt, W., Fiedler, F., … Pausch, G. (2014). Range assessment in particle therapy based on promptγ-ray timing measurements. Physics in Medicine and Biology, 59(18), 5399-5422. doi:10.1088/0031-9155/59/18/5399Cambraia Lopes, P., Clementel, E., Crespo, P., Henrotin, S., Huizenga, J., Janssens, G., … Schaart, D. R. (2015). Time-resolved imaging of prompt-gamma rays for proton range verification using a knife-edge slit camera based on digital photon counters. Physics in Medicine and Biology, 60(15), 6063-6085. doi:10.1088/0031-9155/60/15/6063Petzoldt, J., Roemer, K. E., Enghardt, W., Fiedler, F., Golnik, C., Hueso-González, F., … Pausch, G. (2016). Characterization of the microbunch time structure of proton pencil beams at a clinical treatment facility. Physics in Medicine and Biology, 61(6), 2432-2456. doi:10.1088/0031-9155/61/6/2432Verburg, J. M., & Seco, J. (2014). Proton range verification through prompt gamma-ray spectroscopy. Physics in Medicine and Biology, 59(23), 7089-7106. doi:10.1088/0031-9155/59/23/7089Hueso-González, F., Enghardt, W., Fiedler, F., Golnik, C., Janssens, G., Petzoldt, J., … Pausch, G. (2015). First test of the prompt gamma ray timing method with heterogeneous targets at a clinical proton therapy facility. Physics in Medicine and Biology, 60(16), 6247-6272. doi:10.1088/0031-9155/60/16/6247Martins, P. M., Dal Bello, R., Rinscheid, A., Roemer, K., Werner, T., Enghardt, W., … Seco, J. (2017). Prompt gamma spectroscopy for range control with CeBr3. Current Directions in Biomedical Engineering, 3(2), 113-117. doi:10.1515/cdbme-2017-0023Gil, E. C., Albarrán, E. M., Minucci, E., Nüssle, G., Padolski, S., Petrov, P., … Kozhuharov, V. (2017). The beam and detector of the NA62 experiment at CERN. Journal of Instrumentation, 12(05), P05025-P05025. doi:10.1088/1748-0221/12/05/p05025Schüttauf, A. (2004). Timing RPCs in FOPI. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 533(1-2), 65-68. doi:10.1016/j.nima.2004.07.002Alici, A. (2012). Status and performance of the ALICE MRPC-based Time-Of-Flight detector. Journal of Instrumentation, 7(10), P10024-P10024. doi:10.1088/1748-0221/7/10/p10024Blanco, A., Fonte, P., Garzon, J. A., Koenig, W., Kornakov, G., & Lopes, L. (2013). Performance of the HADES-TOF RPC wall in a Au + Au beam at 1.25 AGeV. Journal of Instrumentation, 8(01), P01004-P01004. doi:10.1088/1748-0221/8/01/p01004Sadrozinski, H. F.-W., Ely, S., Fadeyev, V., Galloway, Z., Ngo, J., Parker, C., … Vinattieri, A. (2013). Ultra-fast silicon detectors. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 730, 226-231. doi:10.1016/j.nima.2013.06.033Cartiglia, N., Staiano, A., Sola, V., Arcidiacono, R., Cirio, R., Cenna, F., … Zavrtanik, M. (2017). Beam test results of a 16 ps timing system based on ultra-fast silicon detectors. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 850, 83-88. doi:10.1016/j.nima.2017.01.021Sadrozinski, H. F.-W., Seiden, A., & Cartiglia, N. (2017). 4D tracking with ultra-fast silicon detectors. Reports on Progress in Physics, 81(2), 026101. doi:10.1088/1361-6633/aa94d3Beddar, A. S., Mackie, T. R., & Attix, F. H. (1992). Water-equivalent plastic scintillation detectors for high-energy beam dosimetry: I. Physical characteristics and theoretical considerations. Physics in Medicine and Biology, 37(10), 1883-1900. doi:10.1088/0031-9155/37/10/006Beddar, A. S., Mackie, T. R., & Attix, F. H. (1992). Water-equivalent plastic scintillation detectors for high-energy beam dosimetry: II. Properties and measurements. Physics in Medicine and Biology, 37(10), 1901-1913. doi:10.1088/0031-9155/37/10/007Beaulieu, L., & Beddar, S. (2016). Review of plastic and liquid scintillation dosimetry for photon, electron, and proton therapy. Physics in Medicine and Biology, 61(20), R305-R343. doi:10.1088/0031-9155/61/20/r305Beddar, S., & Beaulieu, L. (Eds.). (2016). Scintillation Dosimetry. Imaging in Medical Diagnosis and Therapy. doi:10.1201/b19491Marcatili, S., Collot, J., Curtoni, S., Dauvergne, D., Hostachy, J.-Y., Koumeir, C., … Yamouni, M. (2020). Ultra-fast prompt gamma detection in single proton counting regime for range monitoring in particle therapy. Physics in Medicine & Biology, 65(24), 245033. doi:10.1088/1361-6560/ab7a6cKirn, T. (2017). SciFi – A large scintillating fibre tracker for LHCb. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 845, 481-485. doi:10.1016/j.nima.2016.06.057Leverington, B. D., Dziewiecki, M., Renner, L., & Runze, R. (2018). A prototype scintillating fibre beam profile monitor for Ion Therapy beams. Journal of Instrumentation, 13(05), P05030-P05030. doi:10.1088/1748-0221/13/05/p05030Vignati, A., Monaco, V., Attili, A., Cartiglia, N., Donetti, M., Mazinani, M. F., … Cirio, R. (2017). Innovative thin silicon detectors for monitoring of therapeutic proton beams: preliminary beam tests. Journal of Instrumentation, 12(12), C12056-C12056. doi:10.1088/1748-0221/12/12/c12056Krimmer, J., Dauvergne, D., Létang, J. M., & Testa, É. (2018). Prompt-gamma monitoring in hadrontherapy: A review. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 878, 58-73. doi:10.1016/j.nima.2017.07.063Pausch, G., Berthold, J., Enghardt, W., Römer, K., Straessner, A., Wagner, A., … Kögler, T. (2020). Detection systems for range monitoring in proton therapy: Needs and challenges. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 954, 161227. doi:10.1016/j.nima.2018.09.062Hueso-Gonzalez, F., & Bortfeld, T. (2020). Compact Method for Proton Range Verification Based on Coaxial Prompt Gamma-Ray Monitoring: A Theoretical Study. IEEE Transactions on Radiation and Plasma Medical Sciences, 4(2), 170-183. doi:10.1109/trpms.2019.2930362Haberer, T., Debus, J., Eickhoff, H., Jäkel, O., Schulz-Ertner, D., & Weber, U. (2004). The heidelberg ion therapy center. Radiotherapy and Oncology, 73, S186-S190. doi:10.1016/s0167-8140(04)80046-xHara, K., Hata, K., Kim, S., Mishina, M., Sano, M., Seiya, Y., … Yasuoka, K. (1998). Radiation hardness and mechanical durability of Kuraray optical fibers. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 411(1), 31-40. doi:10.1016/s0168-9002(98)00281-2Joram, C., Haefeli, G., & Leverington, B. (2015). Scintillating Fibre Tracking at High Luminosity Colliders. Journal of Instrumentation, 10(08), C08005-C08005. doi:10.1088/1748-0221/10/08/c08005EkelhofRJ Studies for the LHCb SciFi Tracker - Development of Modules from Scintillating Fibres and Tests of their Radiation Hardness2016Online control of particle therapy - CLaRyS collaboration1825 DauvergneD Final MediNet Network Meeting2019Tessonnier, T., Mairani, A., Chen, W., Sala, P., Cerutti, F., Ferrari, A., … Parodi, K. (2018). Proton and helium ion radiotherapy for meningioma tumors: a Monte Carlo-based treatment planning comparison. Radiation Oncology, 13(1). doi:10.1186/s13014-017-0944-3Mein, S., Dokic, I., Klein, C., Tessonnier, T., Böhlen, T. T., Magro, G., … Mairani, A. (2019). Biophysical modeling and experimental validation of relative biological effectiveness (RBE) for 4He ion beam therapy. Radiation Oncology, 14(1). doi:10.1186/s13014-019-1295-zSchoemers, C., Feldmeier, E., Naumann, J., Panse, R., Peters, A., & Haberer, T. (2015). The intensity feedback system at Heidelberg Ion-Beam Therapy Centre. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 795, 92-99. doi:10.1016/j.nima.2015.05.054Werner, F., Bauer, C., Bernhard, S., Capasso, M., Diebold, S., Eisenkolb, F., … Zietara, K. (2017). Performance verification of the FlashCam prototype camera for the Cherenkov Telescope Array. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 876, 31-34. doi:10.1016/j.nima.2016.12.056Actis, M., Agnetta, G., Aharonian, F., Akhperjanian, A., Aleksić, J., … Antico, F. (2011). Design concepts for the Cherenkov Telescope Array CTA: an advanced facility for ground-based high-energy gamma-ray astronomy. Experimental Astronomy, 32(3), 193-316. doi:10.1007/s10686-011-9247-0Dal Bello, R., Magalhaes Martins, P., Graça, J., Hermann, G., Kihm, T., & Seco, J. (2019). Results from the experimental evaluation of CeBr scintillators for He prompt gamma spectroscopy. Medical Physics, 46(8), 3615-3626. doi:10.1002/mp.13594Puehlhofer, G., Bauer, C., Bernhard, S., Capasso, M., Diebold, S., Eisenkolb, F., … Zietara, K. (2016). FlashCam: a fully-digital camera for the medium-sized telescopes of the Cherenkov Telescope Array. Proceedings of The 34th International Cosmic Ray Conference — PoS(ICRC2015). doi:10.22323/1.236.1039Testa, M., Bajard, M., Chevallier, M., Dauvergne, D., Freud, N., Henriquet, P., … Testa, E. (2010). Real-time monitoring of the Bragg-peak position in ion therapy by means of single photon detection. Radiation and Environmental Biophysics, 49(3), 337-343. doi:10.1007/s00411-010-0276-2Dal Bello, R., Magalhaes Martins, P., Brons, S., Hermann, G., Kihm, T., Seimetz, M., & Seco, J. (2020). Prompt gamma spectroscopy for absolute range verification of 12C ions at synchrotron-based facilities. Physics in Medicine & Biology, 65(9), 095010. doi:10.1088/1361-6560/ab797321768 LeoWR Techniques for Nuclear and Particle Physics Experiments: A How-to Approach1994Graeff, C., Weber, U., Schuy, C., Saito, N., Volz, L., Piersimoni, P., … Kraemer, M. (2018). [OA027] Helium as a range probe in carbon ion therapy. Physica Medica, 52, 11. doi:10.1016/j.ejmp.2018.06.099Mazzucconi, D., Agosteo, S., Ferrarini, M., Fontana, L., Lante, V., Pullia, M., & Savazzi, S. (2018). Mixed particle beam for simultaneous treatment and online range verification in carbon ion therapy: Proof‐of‐concept study. Medical Physics, 45(11), 5234-5243. doi:10.1002/mp.13219Scintillating Fiber Trackers: recent developments and applications204 BlancF 14th ICATPP Conference on Astroparticle, Particle, Space Physics and Detectors for Physics Applications2013JoramC UwerU LeveringtonBD KirnT BachmannS EkelhofRJ LHCb Scintillating Fibre Tracker Engineering Design Review Report: Fibres, Mats and Modules201

Prompt gamma spectroscopy for absolute range verification of 12C ions at synchroton-based facilities

[EN] The physical range uncertainty limits the exploitation of the full potential of charged particle therapy. In this work, we face this issue aiming to measure the absolute Bragg peak position in the target. We investigate p, He-4, C-12 and O-16 beams accelerated at the Heidelberg Ion-Beam Therapy Center. The residual range of the primary C-12 ions is correlated to the energy spectrum of the prompt gamma radiation. The prompt gamma spectroscopy method was demonstrated for proton beams accelerated by cyclotrons and is developed here for the first time for heavier ions accelerated by a synchrotron. We develop a detector system that includes (i) a spectroscopic unit based on cerium(III) bromide and bismuth germanium oxide scintillating crystals, (ii) a beam trigger based on an array of scintillating fibers and (iii) a data acquisition system based on a FlashADC. We test the system in two different scenarios. In the first series of experiments, we detect and identify 19 independent spectral lines over a wide gamma energy spectrum in the presence of the four ion species for different targets, including a water target with a titanium insert. In the second series of experiments, we introduce a collimator aiming to relate the spectral information to the range of the primary particles. We perform extensive measurements for a C-12 beam and demonstrate submillimetric precision for the measurement of its Bragg peak position in the experimental setup. The features of the energy and time spectra for gamma radiation induced by p, He-4 and O-16 are investigated upstream and downstream from the Bragg peak position. We conclude the analysis by extrapolating the required future developments, which would be needed to achieve range verification with a 2 mm accuracy during a single fraction delivery of D=2 Gy<i physical dose.The author R.D.B. is supported by the International Max Planck Research School for Quantum Dynamics in Physics, Chemistry and Biology, Heidelberg, Germany. P.M.M. is supported by a research fellowship for postdoctoral researchers from the Alexander von Humboldt Foundation, Bonn, Germany. The authors thank the Radiation Protection Department of the DKFZ, in particular Mechthild Kammer, for the support with calibration sources. The authors also thank the staff of the Department of Medical Physics in Radiation Oncology of the DKFZ, in particular Gernot Echner, Armin Runz and Peter Haring for the support with the experimental setup.Dal Bello, R.; Martins, PM.; Brons, S.; Hermann, G.; Kihm, T.; Seimetz, M.; Seco, J. (2020). Prompt gamma spectroscopy for absolute range verification of 12C ions at synchroton-based facilities. Physics in Medicine and Biology. 65(9):1-23. https://doi.org/10.1088/1361-6560/ab7973S123659Amaldi, U., & Kraft, G. (2005). Radiotherapy with beams of carbon ions. Reports on Progress in Physics, 68(8), 1861-1882. doi:10.1088/0034-4885/68/8/r04Aricò, G., Gehrke, T., Gallas, R., Mairani, A., Jäkel, O., & Martišíková, M. (2019). Investigation of single carbon ion fragmentation in water and PMMA for hadron therapy. Physics in Medicine & Biology, 64(5), 055018. doi:10.1088/1361-6560/aafa46Böhlen, T. T., Cerutti, F., Chin, M. P. W., Fassò, A., Ferrari, A., Ortega, P. G., … Vlachoudis, V. (2014). The FLUKA Code: Developments and Challenges for High Energy and Medical Applications. Nuclear Data Sheets, 120, 211-214. doi:10.1016/j.nds.2014.07.049Bragg, W. H., & Kleeman, R. (1905). XXXIX. On the α particles of radium, and their loss of range in passing through various atoms and molecules. The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science, 10(57), 318-340. doi:10.1080/14786440509463378Brun, R., & Rademakers, F. (1997). ROOT — An object oriented data analysis framework. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 389(1-2), 81-86. doi:10.1016/s0168-9002(97)00048-xCastriconi, R., Ciocca, M., Mirandola, A., Sini, C., Broggi, S., Schwarz, M., … Russo, P. (2016). Dose–response of EBT3 radiochromic films to proton and carbon ion clinical beams. Physics in Medicine and Biology, 62(2), 377-393. doi:10.1088/1361-6560/aa5078Guttormsen, M., Tveter, T. ., Bergholt, L., Ingebretsen, F., & Rekstad, J. (1996). The unfolding of continuum γ-ray spectra. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 374(3), 371-376. doi:10.1016/0168-9002(96)00197-0Haberer, T., Debus, J., Eickhoff, H., Jäkel, O., Schulz-Ertner, D., & Weber, U. (2004). The heidelberg ion therapy center. Radiotherapy and Oncology, 73, S186-S190. doi:10.1016/s0167-8140(04)80046-xHueso-González, F., Rabe, M., Ruggieri, T. A., Bortfeld, T., & Verburg, J. M. (2018). A full-scale clinical prototype for proton range verification using prompt gamma-ray spectroscopy. Physics in Medicine & Biology, 63(18), 185019. doi:10.1088/1361-6560/aad513Kelleter, L., Wrońska, A., Besuglow, J., Konefał, A., Laihem, K., Leidner, J., … Tessonnier, T. (2017). Spectroscopic study of prompt-gamma emission for range verification in proton therapy. Physica Medica, 34, 7-17. doi:10.1016/j.ejmp.2017.01.003Knopf, A.-C., & Lomax, A. (2013). In vivoproton range verification: a review. Physics in Medicine and Biology, 58(15), R131-R160. doi:10.1088/0031-9155/58/15/r131Kozlovsky, B., Murphy, R. J., & Ramaty, R. (2002). Nuclear Deexcitation Gamma‐Ray Lines from Accelerated Particle Interactions. The Astrophysical Journal Supplement Series, 141(2), 523-541. doi:10.1086/340545Krimmer, J., Dauvergne, D., Létang, J. M., & Testa, É. (2018). Prompt-gamma monitoring in hadrontherapy: A review. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 878, 58-73. doi:10.1016/j.nima.2017.07.063Leverington, B. D., Dziewiecki, M., Renner, L., & Runze, R. (2018). A prototype scintillating fibre beam profile monitor for Ion Therapy beams. Journal of Instrumentation, 13(05), P05030-P05030. doi:10.1088/1748-0221/13/05/p05030Mein, S., Choi, K., Kopp, B., Tessonnier, T., Bauer, J., Ferrari, A., … Mairani, A. (2018). Fast robust dose calculation on GPU for high-precision 1H, 4He, 12C and 16O ion therapy: the FRoG platform. Scientific Reports, 8(1). doi:10.1038/s41598-018-33194-4Paganetti, H. (2012). Range uncertainties in proton therapy and the role of Monte Carlo simulations. Physics in Medicine and Biology, 57(11), R99-R117. doi:10.1088/0031-9155/57/11/r99Panaino, C., Taylor, M. J., MacKay, R., Merchant, M. J., Price, T., Pheonix, B., & Green, S. (2018). Abstract ID: 171 A Monte Carlo study to reduce range uncertainty in proton beam therapy via prompt gamma-ray detection. Physica Medica, 45, S2. doi:10.1016/j.ejmp.2017.11.027Pinto, M., Bajard, M., Brons, S., Chevallier, M., Dauvergne, D., Dedes, G., … Testa, M. (2014). Absolute prompt-gamma yield measurements for ion beam therapy monitoring. Physics in Medicine and Biology, 60(2), 565-594. doi:10.1088/0031-9155/60/2/565Quarati, F. G. A., Dorenbos, P., van der Biezen, J., Owens, A., Selle, M., Parthier, L., & Schotanus, P. (2013). Scintillation and detection characteristics of high-sensitivity CeBr3 gamma-ray spectrometers. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 729, 596-604. doi:10.1016/j.nima.2013.08.005Dal Bello, R., Magalhaes Martins, P., & Seco, J. (2018). CeBr3scintillators for4He prompt gamma spectroscopy: Results from a Monte Carlo optimization study. Medical Physics, 45(4), 1622-1630. doi:10.1002/mp.12795Dal Bello, R., Magalhaes Martins, P., Graça, J., Hermann, G., Kihm, T., & Seco, J. (2019). Results from the experimental evaluation of CeBr scintillators for He prompt gamma spectroscopy. Medical Physics, 46(8), 3615-3626. doi:10.1002/mp.13594Roemer, K., Pausch, G., Bemmerer, D., Berthel, M., Dreyer, A., Golnik, C., … Fiedler, F. (2015). Characterization of scintillator crystals for usage as prompt gamma monitors in particle therapy. Journal of Instrumentation, 10(10), P10033-P10033. doi:10.1088/1748-0221/10/10/p10033Testa, M., Bajard, M., Chevallier, M., Dauvergne, D., Freud, N., Henriquet, P., … Testa, E. (2010). Real-time monitoring of the Bragg-peak position in ion therapy by means of single photon detection. Radiation and Environmental Biophysics, 49(3), 337-343. doi:10.1007/s00411-010-0276-2Tommasino, F., Scifoni, E., & Durante, M. (2015). New Ions for Therapy. International Journal of Particle Therapy, 2(3), 428-438. doi:10.14338/ijpt-15-00027.1Vanstalle, M., Mattei, I., Sarti, A., Bellini, F., Bini, F., Collamati, F., … Tessa, C. L. (2017). Benchmarking Geant4 hadronic models for prompt‐ γ monitoring in carbon ion therapy. Medical Physics, 44(8), 4276-4286. doi:10.1002/mp.12348Verburg, J. M., Riley, K., Bortfeld, T., & Seco, J. (2013). Energy- and time-resolved detection of prompt gamma-rays for proton range verification. Physics in Medicine and Biology, 58(20), L37-L49. doi:10.1088/0031-9155/58/20/l37Verburg, J. M., & Seco, J. (2014). Proton range verification through prompt gamma-ray spectroscopy. Physics in Medicine and Biology, 59(23), 7089-7106. doi:10.1088/0031-9155/59/23/7089Werner, F., Bauer, C., Bernhard, S., Capasso, M., Diebold, S., Eisenkolb, F., … Zietara, K. (2017). Performance verification of the FlashCam prototype camera for the Cherenkov Telescope Array. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 876, 31-34. doi:10.1016/j.nima.2016.12.05

Position statement of the German STI Society on the prophylactic use of doxycycline to prevent STIs (Doxy-PEP, Doxy-PrEP)

Over the past two decades, there has been a rise in the incidence of syphilis, particularly among men who have sex with men (MSM). This has sparked interest in studying the prophylactic use of doxycycline to prevent syphilis and other sexually transmitted infections (STIs), commonly referred to as Doxycycline Pre- or Post-Exposure Prophylaxis (Doxy-PrEP, Doxy-PEP). At the same time, demand from potential users for this preventive measure is increasing. Several randomized controlled trials have demonstrated that the prophylactic use of doxycycline in MSM and trans women using HIV pre-exposure prophylaxis (HIV-PrEP) or living with an HIV infection effectively reduces the risk of syphilis and chlamydia infections. At present, however, unresolved questions remain, particularly regarding implications of a broad implementation of prophylactic doxycycline to prevent STIs on tetracycline and other antimicrobial resistance in bacterial STIs, non-STI-related bacterial pathogens, and the microbiome. In response to the increasing demand and the challenge of balancing effectiveness, safety, and the risk of promoting antibiotic resistance, the German STI Society (DSTIG) has issued a position statement, providing specific recommendations regarding potential indications, criteria, and occasions for the use of doxycycline in STI prevention. These recommendations are based on current evidence and expert opinion

Low fertility and population replacement in Scotland

It has been argued that Scotland faces population ageing and decline that will have potentially serious economic and social consequences, and that the origin of these processes lie in its low and declining fertility rates. After considering alternatives to the total period rate measure of fertility, empirical evidence and theoretical argument about low fertility and its consequences is briefly reviewed. The paper argues that low fertility in general may not be the problem it is often purported to be, that Scotland has relatively high fertility, and that pro-natalist policies are neither desirable nor necessary. It suggests that low fertility and population ageing may be viewed as positive developments, and that within Europe, Scotland is distinguished more by its excess of early deaths than by any shortage of births.Peer reviewe

Performance of the New FlashCam-based Camera in the 28\,m Telescope of H.E.S.S

In October 2019, the central 28 m telescope of the H.E.S.S. experiment has been upgraded with a new camera. The camera is based on the FlashCam design which has been developed in view of a possible future implementation in the Medium-Sized Telescopes of the Cherenkov Telescope Array (CTA), with emphasis on cost and performance optimization and on reliability. The fully digital design of the trigger and readout system makes it possible to operate the camera at high event rates and to precisely adjust and understand the trigger system. The novel design of the front-end electronics achieves a dynamic range of over 3,000 photoelectrons with only one electronics readout circuit per pixel. Here we report on the performance parameters of the camera obtained during the first year of operation in the field, including operational stability and optimization of calibration algorithms.Comment: Proceedings of the 37th International Cosmic Ray Conference (ICRC 2021

2D to 3D crossover of the magnetic properties in ordered arrays of iron oxide nanocrystals

The magnetic 2D to 3D crossover behavior of well-ordered arrays of monodomain gamma-Fe2O3 spherical nanoparticles with different thicknesses has been investigated by magnetometry and Monte Carlo (MC) simulations. Using the structural information of the arrays obtained from grazing incidence small-angle X-ray scattering and scanning electron microscopy together with the experimentally determined values for the saturation magnetization and magnetic anisotropy of the nanoparticles, we show that MC simulations can reproduce the thickness-dependent magnetic behavior. The magnetic dipolar particle interactions induce a ferromagnetic coupling that increases in strength with decreasing thickness of the array. The 2D to 3D transition in the magnetic properties is mainly driven by a change in the orientation of the magnetic vortex states with increasing thickness, becoming more isotropic as the thickness of the array increases. Magnetic anisotropy prevents long-range ferromagnetic order from being established at low temperature and the nanoparticle magnetic moments instead freeze along directions defined by the distribution of easy magnetization directions

Submarine back-arc lava with arc signature : Fonualei Spreading Center, northeast Lau Basin, Tonga

Author Posting. © American Geophysical Union, 2008. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 113 (2008): B08S07, doi:10.1029/2007JB005451.We present major, volatile, and trace elements for quenched glasses from the Fonualei Spreading Center, a nascent spreading system situated very close to the Tofua Volcanic Arc (20 km at the closest), in the northeast Lau Basin. The glasses are basalts and basaltic andesites and are inferred to have originated from a relatively hot and depleted mantle wedge. The Fonualei Spreading Center shows island arc basalt (IAB) affinities, indistinguishable from the Tofua Arc. Within the Fonualei Spreading Center no geochemical trends can be seen with depth to the slab and/or distance to the arc, despite a difference in depth to the slab of >50 km. Therefore we infer that all the subduction-related magmatism is captured by the back arc as the adjacent arc is shut off. There is a sharp contrast between the main spreading area of the Fonualei Spreading Center (FSC) and its northernmost termination, the Mangatolu Triple Junction (MTJ). The MTJ samples are characteristic back-arc basin basalts (BABB). We propose that the MTJ and FSC have different mantle sources, reflecting different mantle origins and/or different melting processes. We also document a decrease in mantle depletion from the south of the FSC to the MTJ, which is the opposite to what has been documented for the rest of the Lau Basin where depletion generally increases from south to north. We attribute this reverse trend to the influx of less depleted mantle through the tear between the Australian and the Pacific plates, at the northern boundary of the Lau Basin.NSK acknowledges the support of an A.E. Ringwood Scholarship from the RSES