@article{AuffrayBruyndonckxDevroedeetal.2004,
  author    = {Auffray, E. and Bruyndonckx, P. and Devroede, O. and Fedorov, A. and Ziemons, Karl},
  title     = {The ClearPET project},
  series = {Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment},
  volume    = {527},
  journal   = {Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment},
  number    = {1-2},
  isbn      = {0168-9002},
  pages     = {171 -- 174},
  year      = {2004},
  abstract  = {The Crystal Clear Collaboration has designed and is building a high-resolution small animal PET scanner. The design is based on the use of the Hamamatsu R7600-M64 multi-anode photomultiplier tube and a LSO/LuYAP phoswich matrix with one to one coupling between the crystals and the photo-detector. The complete system will have 80 PM tubes in four rings with an inner diameter of 137 mm and an axial field of view of 110 mm. The PM pulses are digitized by free-running ADCs and digital data processing determines the gamma energy, the phoswich layer and even the pulse arrival time. Single gamma interactions are recorded and coincidences are found by software. The gantry allows rotation of the detector modules around the field of view. Simulations, and measurements a 2×4 module test set-up predict a spatial resolution of 1.5 mm in the centre of the field of view and a sensitivity of 5.9\% for a point source in the centre of the field of view.},
  language  = {en}
}
@article{StreunChristHellendungetal.2005,
  author    = {Streun, M. and Christ, D. and Hellendung, A. and Larue, H. and Ziemons, Karl and Halling, H.},
  title     = {Effects of crosstalk and gain nonuniformity using multichannel PMTs in the Clearpet® scanner},
  series = {Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment},
  volume    = {537},
  journal   = {Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment},
  number    = {1-2},
  isbn      = {0168-9002},
  pages     = {402 -- 405},
  year      = {2005},
  abstract  = {The ClearPET® scanners developed by the Crystal Clear Collaboration use multichannel PMTs as photodetectors with scintillator pixels coupled individually to each channel. In order to localize an event each channel anode is connected to a comparator that triggers when the anode signal exceeds a common predefined threshold. Two major difficulties here are crosstalk of light and the gain nonuniformity of the PMT channels. Crosstalk can generate false triggering in channels adjacent to the actual event. On the one hand this can be suppressed by sufficiently increasing the threshold, but on the other hand a threshold too high can already prevent valid events on the lower gain channels from being detected. Finally, both effects restrict the dynamic range of pulse heights that can be processed. The requirements to the dynamic range are not low as the ClearPET® scanners detect the depth of interaction by phoswich pixels consisting of LSO and Lu0.7Y0.3AP, two scintillators with different light yields. We will present a model to estimate the achievable dynamic range and show solutions to increase it.},
  language  = {en}
}
@article{ZiemonsAuffrayBarbieretal.2005,
  author    = {Ziemons, Karl and Auffray, E. and Barbier, R. and Brandenburg, G. and Bruyndonckx, P.},
  title     = {The ClearPET™ project: Development of a 2nd generation high-performance small animal PET scanner},
  series = {Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment},
  volume    = {537},
  journal   = {Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment},
  number    = {1-2},
  issn      = {0168-9002},
  pages     = {307 -- 311},
  year      = {2005},
  abstract  = {Second generation high-performance PET scanners, called ClearPET™1, have been developed by working groups of the Crystal Clear Collaboration (CCC). High sensitivity and high spatial resolution for the ClearPET camera is achieved by using a phoswich arrangement combining two different types of lutetium-based scintillator materials: LSO from CTI and LuYAP:Ce from the CCC (ISTC project). In a first ClearPET prototype, phoswich arrangements of 8×8 crystals of 2×2×10 mm3 are coupled to multi-channel photomultiplier tubes (Hamamatsu R7600). A unit of four PMTs arranged in-line represents one of 20 sectors of the ring design. The opening diameter of the ring is 120 mm, the axial detector length is 110 mm.The PMT pulses are digitized by free-running ADCs and digital data processing determines the gamma energy, the phoswich layer and even the exact pulse starting time, which is subsequently used for coincidence detection. The gantry allows rotation of the detector modules around the field of view. Preliminary data shows a correct identification of the crystal layer about (98±1)\%. Typically the energy resolution is (23.3±0.5)\% for the luyap layer and (15.4±0.4)\% for the lso layer. early studies showed the timing resolution of 2 ns FWHM and 4.8 ns FWTM. the intrinsic spatial resolution ranges from 1.37 mm to 1.61 mm full-width of half-maximum (FWHM) with a mean of 1.48 mm FWHM. further improvements in image and energy resolution are expected when the system geometry is fully modeled.},
  language  = {en}
}
@article{BeerStreunHombachetal.2010,
  author    = {Beer, S. and Streun, M. and Hombach, T. and Buehler, J. and Jahnke, S. and Khodaverdi, M. and Larue, H. and Minwuyelet, S. and Parl, C. and Roeb, G. and Schurr, U. and Ziemons, Karl},
  title     = {Design and initial performance of PlanTIS: a high-resolution positron emission tomograph for plants},
  series = {Physics in Medicine and Biology},
  volume    = {55},
  journal   = {Physics in Medicine and Biology},
  number    = {3},
  publisher = {IOP},
  address   = {Bristol},
  issn      = {1361-6560},
  doi       = {10.1088/0031-9155/55/3/006},
  pages     = {635 -- 646},
  year      = {2010},
  abstract  = {Positron emitters such as 11C, 13N and 18F and their labelled compounds are widely used in clinical diagnosis and animal studies, but can also be used to study metabolic and physiological functions in plants dynamically and in vivo. A very particular tracer molecule is 11CO2 since it can be applied to a leaf as a gas. We have developed a Plant Tomographic Imaging System (PlanTIS), a high-resolution PET scanner for plant studies. Detectors, front-end electronics and data acquisition architecture of the scanner are based on the ClearPET™ system. The detectors consist of LSO and LuYAP crystals in phoswich configuration which are coupled to position-sensitive photomultiplier tubes. Signals are continuously sampled by free running ADCs, and data are stored in a list mode format. The detectors are arranged in a horizontal plane to allow the plants to be measured in the natural upright position. Two groups of four detector modules stand face-to-face and rotate around the field-of-view. This special system geometry requires dedicated image reconstruction and normalization procedures. We present the initial performance of the detector system and first phantom and plant measurements.},
  language  = {en}
}
@article{HerzogPietrzykShahetal.2010,
  author    = {Herzog, Hans and Pietrzyk, Uwe and Shah, N. Jon and Ziemons, Karl},
  title     = {The current state, challenges and perspectives of MR-PET},
  series = {Neuroimage},
  volume    = {49},
  journal   = {Neuroimage},
  number    = {3},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1053-8119},
  doi       = {10.1016/j.neuroimage.2009.10.036},
  pages     = {2072 -- 2082},
  year      = {2010},
  abstract  = {Following the success of PET/CT during the last decade and the recent increasing proliferation of SPECT/CT, another hybrid imaging instrument has been gaining more and more interest: MR-PET. First combined, simultaneous PET and MR studies carried out in small animals demonstrated the feasibility of the new approach. Concurrently, some prototypes of an MR-PET scanner for simultaneous human brain studies have been built, their performance is being tested and preliminary applications have already been shown. Through this pioneering work, it has become clear that advances in the detector design are necessary for further optimization. Recently, the different issues related to the present state and future prospects of MR-PET were presented and discussed during an international 2-day workshop at the Forschungszentrum J{\"u}lich, Germany, held after, and in conjunction with, the 2008 IEEE Nuclear Science Symposium and Medical Imaging Conference in Dresden, Germany on October 27-28, 2008. The topics ranged from small animal MR-PET imaging to human MR-BrainPET imaging, new detector developments, challenges/opportunities for ultra-high field MR-PET imaging and considerations of possible future research and clinical applications. This report presents a critical summary of the contributions made to the workshop.},
  language  = {en}
}
@article{ParlLarueStreunetal.2011,
  author    = {Parl, C. and Larue, H. and Streun, M. and Ziemons, Karl},
  title     = {Double-side-readout technique for SiPM-matrices},
  series = {2010 IEEE Nuclear Science Symposium Conference Record (NSS/MIC)},
  journal   = {2010 IEEE Nuclear Science Symposium Conference Record (NSS/MIC)},
  publisher = {IEEE},
  address   = {New York},
  issn      = {1095-7863},
  pages     = {1486 -- 1487},
  year      = {2011},
  abstract  = {In our case the double-side-method is used to minimize the complexity of a matrix-readout. Here the number of channels is reduced to 2√N̅. It is also possible to benefit from the method in a single pixel readout system. One signal can be used to measure position and energy of the event, the other one can be applied to a fast trigger-circuit at the same time. In a next step we will investigate timing behavior and electrical crosstalk of the circuit.},
  language  = {en}
}
@inproceedings{StreunAlKaddoumParletal.2012,
  author    = {Streun, M. and Al-Kaddoum, R. and Parl, C. and Pietrzyk, U. and Ziemons, Karl and Waasen, S. van},
  title     = {Simulation studies of optical photons in monolithic block scintillators},
  series = {2011 IEEE Nuclear Science Symposium Conference Record (NSS/MIC)},
  booktitle = {2011 IEEE Nuclear Science Symposium Conference Record (NSS/MIC)},
  publisher = {IEEE},
  address   = {New York},
  isbn      = {978-1-4673-0120-6 (electronic ISBN)},
  doi       = {10.1109/NSSMIC.2011.6154621},
  pages     = {1380 -- 1382},
  year      = {2012},
  abstract  = {The interest in PET detectors with monolithic block scintillators is growing. In order to obtain high spatial resolutions dedicated positioning algorithms are required. But even an ideal algorithm can only deliver information which is provided by the detector. In this simulation study we investigated the light distribution on one surface of cuboid LSO scintillators of different size. Scintillators with a large aspect ratio (small footprint and large height) showed significant position information only for a minimum interaction depth of the gamma particle. The results allow a quantitative estimate for a useful aspect ratio.},
  language  = {en}
}
@article{GebhardtFateri2013,
  author    = {Gebhardt, Andreas and Fateri, Miranda},
  title     = {3D printing and its applications},
  series = {RTejournal - Forum f{\"u}r Rapid Technologie},
  volume    = {10},
  journal   = {RTejournal - Forum f{\"u}r Rapid Technologie},
  number    = {1},
  publisher = {Fachhochschule Aachen},
  address   = {Aachen},
  issn      = {1614-0923},
  url       = {http://nbn-resolving.de/urn:nbn:de:0009-2-35626},
  year      = {2013},
  abstract  = {Eine zunehmende Anzahl von Artikeln in Publikumszeitschriften und Journalen r{\"u}ckt die direkte Herstellung von Bauteilen und Figuren immer mehr in das Bewusstsein einer breiten {\"O}ffentlichkeit. Leider ergibt sich nur selten ein einigermaßen vollst{\"a}ndiges Bild davon, wie und in welchen Lebensbereichen diese Techniken unseren Alltag ver{\"a}ndern werden. Das liegt auch daran, dass die meisten Artikel sehr technisch gepr{\"a}gt sind und sich nur punktuell auf Beispiele st{\"u}tzen. Dieser Beitrag geht von den Bed{\"u}rfnissen der Menschen aus, wie sie z.B. in der Maslow'schen Bed{\"u}rfnispyramide strukturiert dargestellt sind und unterstreicht dadurch, dass 3D Printing (oder Additive Manufacturing resp. Rapid Prototyping) bereits alle Lebensbereiche erfasst hat und im Begriff ist, viele davon zu revolutionieren.},
  language  = {en}
}
@article{KirchnerOberlaenderSusoetal.2013,
  author    = {Kirchner, Patrick and Oberl{\"a}nder, Jan and Suso, Henri-Pierre and Rysstad, Gunnar and Keusgen, Michael and Sch{\"o}ning, Michael Josef},
  title     = {Towards a wireless sensor system for real-time H2O2 monitoring in aseptic food processes},
  series = {Physica status solidi (a)},
  volume    = {210},
  journal   = {Physica status solidi (a)},
  number    = {5},
  publisher = {Wiley},
  address   = {Weinheim},
  issn      = {1862-6319},
  doi       = {10.1002/pssa.201200920},
  pages     = {877 -- 883},
  year      = {2013},
  abstract  = {A wireless sensor system based on the industrial ZigBee standard for low-rate wireless networking was developed that enables real-time monitoring of gaseous H2O2 during the package sterilization in aseptic food processes. The sensor system consists of a remote unit connected to a calorimetric gas sensor, which was already established in former works, and an external base unit connected to a laptop computer. The remote unit was built up by an XBee radio frequency (RF) module for data communication and a programmable system-on-chip controller to read out the sensor signal and process the sensor data, whereas the base unit is a second XBee RF module. For the rapid H2O2 detection on various locations inside the package that has to be sterilized, a novel read-out strategy of the calorimetric gas sensor was established, wherein the sensor response is measured within the short sterilization time and correlated with the present H2O2 concentration. In an exemplary measurement application in an aseptic filling machinery, the suitability of the new, wireless sensor system was demonstrated, wherein the influence of the gas velocity on the H2O2 distribution inside a package was determined and verified with microbiological tests.},
  language  = {en}
}
@article{KhodaverdiChatziioannouWeberetal.2005,
  author    = {Khodaverdi, M. and Chatziioannou, A. F. and Weber, S. and Ziemons, Karl and Halling, H. and Pietrzyk, U.},
  title     = {Investigation of different MicroCT scanner configurations by GEANT4 simulations},
  series = {IEEE Transactions on Nuclear Science},
  volume    = {52},
  journal   = {IEEE Transactions on Nuclear Science},
  number    = {1},
  isbn      = {0018-9499},
  pages     = {188 -- 192},
  year      = {2005},
  abstract  = {This study has been performed to design the combination of the new ClearPET (ClearPET is a trademark of the Crystal Clear Collaboration), a small animal positron emission tomography (PET) system, with a micro-computed tomography (microCT) scanner. The properties of different microCT systems have been determined by simulations based on GEANT4. We will demonstrate the influence of the detector material and the X-ray spectrum on the obtained contrast. Four different detector materials (selenium, cadmium zinc telluride, cesium iodide and gadolinium oxysulfide) and two X-ray spectra (a molybdenum and a tungsten source) have been considered. The spectra have also been modified by aluminum filters of varying thickness. The contrast between different tissue types (water, air, brain, bone and fat) has been simulated by using a suitable phantom. The results indicate the possibility to improve the image contrast in microCT by an optimized combination of the X-ray source and detector material.},
  language  = {en}
}