@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{HueningWilkeNakielskietal.1997, author = {H{\"u}ning, Felix and Wilke, I. and Nakielski, G. and Kotzler, J.}, title = {Dynamic conductivity of YBCO thin films from low to very high frequencies / Wilke, I. ; Nakielski, G. ; Kotzler, J. ; Subke, K. O. ; Jaekel, C. ; H{\"u}ning, F. ; Roskos, H. G. ; Kurz, Heinrich}, series = {Applied superconductivity 1997 : proceedings of EUCAS 1997, the Third European Conference on Applied Superconductivity, held in the Netherlands, 30 June - 3 July 1997 / ed. by H. Rogalla}, journal = {Applied superconductivity 1997 : proceedings of EUCAS 1997, the Third European Conference on Applied Superconductivity, held in the Netherlands, 30 June - 3 July 1997 / ed. by H. Rogalla}, publisher = {IOP}, address = {Bristol}, isbn = {0-7503-0487-1}, pages = {121 -- 124}, year = {1997}, language = {en} } @article{GuoSekiMiyamotoetal.2014, author = {Guo, Yuanyuan and Seki, Kosuke and Miyamoto, Ko-ichiro and Wagner, Torsten and Sch{\"o}ning, Michael Josef and Yoshinobu, Tatsuo}, title = {Novel photoexcitation method for light-addressable potentiometric sensor with higher spatial resolution}, series = {Applied physics express : APEX}, volume = {7}, journal = {Applied physics express : APEX}, number = {6}, publisher = {IOP}, address = {Bristol}, issn = {1882-0786 (E-Journa); 1882-0778 (Print)}, doi = {10.7567/APEX.7.067301}, pages = {067301-4}, year = {2014}, abstract = {A novel photoexcitation method for the light-addressable potentiometric sensor (LAPS) is proposed to achieve a higher spatial resolution of chemical images. The proposed method employs a combined light source that consists of a modulated light probe, which generates the alternating photocurrent signal, and a ring of constant illumination surrounding it. The constant illumination generates a sheath of carriers with increased concentration which suppresses the spread of photocarriers by enhanced recombination. A device simulation was carried out to verify the effect of constant illumination on the spatial resolution, which demonstrated that a higher spatial resolution can be obtained.}, language = {en} } @article{MichauxMatternKallweit2018, author = {Michaux, F. and Mattern, P. and Kallweit, Stephan}, title = {RoboPIV: how robotics enable PIV on a large industrial scale}, series = {Measurement Science and Technology}, volume = {29}, journal = {Measurement Science and Technology}, number = {7}, publisher = {IOP}, address = {Bristol}, issn = {1361-6501}, doi = {10.1088/1361-6501/aab5c1}, pages = {074009}, year = {2018}, abstract = {This work demonstrates how the interaction between particle image velocimetry (PIV) and robotics can massively increase measurement efficiency. The interdisciplinary approach is shown using the complex example of an automated, large scale, industrial environment: a typical automotive wind tunnel application. Both the high degree of flexibility in choosing the measurement region and the complete automation of stereo PIV measurements are presented. The setup consists of a combination of three robots, individually used as a 6D traversing unit for the laser illumination system as well as for each of the two cameras. Synchronised movements in the same reference frame are realised through a master-slave setup with a single interface to the user. By integrating the interface into the standard wind tunnel management system, a single measurement plane or a predefined sequence of several planes can be requested through a single trigger event, providing the resulting vector fields within minutes. In this paper, a brief overview on the demands of large scale industrial PIV and the existing solutions is given. Afterwards, the concept of RoboPIV is introduced as a new approach. In a first step, the usability of a selection of commercially available robot arms is analysed. The challenges of pose uncertainty and importance of absolute accuracy are demonstrated through comparative measurements, explaining the individual pros and cons of the analysed systems. Subsequently, the advantage of integrating RoboPIV directly into the existing wind tunnel management system is shown on basis of a typical measurement sequence. In a final step, a practical measurement procedure, including post-processing, is given by using real data and results. Ultimately, the benefits of high automation are demonstrated, leading to a drastic reduction in necessary measurement time compared to non-automated systems, thus massively increasing the efficiency of PIV measurements.}, language = {en} } @article{HenriquesJuradoGrieseretal.2020, author = {Henriques, A. and Jurado, B. and Grieser, M. and Denis-Petit, D. and Chiron, T. and Gaudefroy, L. and Glorius, J. and Langer, Christoph and Litvinov, Yu. A. and Mathieu, L. and Meot, V. and Perez-Sanchez, R. and Pibernat, J. and Reifarth, R. and Roig, O. and Thomas, B. and Thomas, B. A. and Thomas, J. C. and Tsekhanovich, I.}, title = {Indirect measurements of neutron cross-secti at heavy-ion storage rings}, series = {Journal of Physics: Conference Series}, volume = {1668}, journal = {Journal of Physics: Conference Series}, number = {Art. 012019}, publisher = {IOP}, address = {Bristol}, doi = {10.1088/1742-6596/1668/1/012019}, year = {2020}, abstract = {Cross sections for neutron-induced reactions of short-lived nuclei are essential for nuclear astrophysics since these reactions in the stars are responsible for the production of most heavy elements in the universe. These reactions are also key in applied domains like energy production and medicine. Nevertheless, neutron-induced cross-section measurements can be extremely challenging or even impossible to perform due to the radioactivity of the targets involved. Indirect measurements through the surrogate-reaction method can help to overcome these difficulties. The surrogate-reaction method relies on the use of an alternative reaction that will lead to the formation of the same excited nucleus as in the neutron-induced reaction of interest. The decay probabilities (for fission, neutron and gamma-ray emission) of the nucleus produced via the surrogate reaction allow one to constrain models and the prediction of the desired neutron cross sections. We propose to perform surrogate reaction measurements in inverse kinematics at heavy-ion storage rings, in particular at the CRYRING@ESR of the GSI/FAIR facility. We present the conceptual idea of the most promising setup to measure for the first time simultaneously the fission, neutron and gamma-ray emission probabilities. The results of the first simulations considering the 238U(d,d') reaction are shown, as well as new technical developments that are being carried out towards this set-up.}, language = {en} } @article{VargaDavinsonGloriusetal.2020, author = {Varga, Laszlo and Davinson, Thomas and Glorius, Jan and Jurado, Beatrix and Langer, Christoph and Lederer-Woods, Claudia and Litvinov, Yuri A. and Reifarth, Rene and Slavkovska, Zuzana and St{\"o}hlker, Thomas and Woods, Phil J. and Xing, Yuan Ming}, title = {Towards background-free studies of capture reaction in a heavy-ion storage ring}, series = {Journal of Physics: Conference Series}, volume = {1668}, journal = {Journal of Physics: Conference Series}, number = {Art 012046}, publisher = {IOP}, address = {Bristol}, year = {2020}, abstract = {Stored and cooled, highly-charged ions offer unprecedented capabilities for precision studies in the realm of atomic, nuclear structure and astrophysics[1]. After the successful investigation of the 96Ru(p,7)97Rh reaction cross section in 2009[2], the first measurement of the 124Xe(p,7)125Cs reaction cross section has been performed with decelerated, fully-ionized 124Xe ions in 2016 at the Experimental Storage Ring (ESR) of GSI[3]. Using a Double Sided Silicon Strip Detector, introduced directly into the ultra-high vacuum environment of a storage ring, the 125Cs proton-capture products have been successfully detected. The cross section has been measured at 5 different energies between 5.5AMeV and 8AMeV, on the high energy tail of the Gamow-window for hot, explosive scenarios such as supernovae and X-ray binaries. The elastic scattering on the H2 gas jet target is the major source of background to count the (p,7) events. Monte Carlo simulations show that an additional slit system in the ESR in combination with the energy information of the Si detector will enable background free measurements of the proton-capture products. The corresponding hardware is being prepared and will increase the sensitivity of the method tremendously.}, language = {en} } @article{ChoiFelderFelderetal.2020, author = {Choi, Chang-Hoon and Felder, Tim and Felder, J{\"o}rg and Tellmann, Lutz and Hong, Suk-Min and Wegener, Hans-Peter and Shah, N Jon and Ziemons, Karl}, title = {Design, evaluation and comparison of endorectal coils for hybrid MR-PET imaging of the prostate}, series = {Physics in Medicine \& Biology}, volume = {65}, journal = {Physics in Medicine \& Biology}, number = {11}, publisher = {IOP}, address = {Bristol}, issn = {0031-9155}, doi = {10.1088/1361-6560/ab87f8}, year = {2020}, abstract = {Prostate cancer is one of the most common cancers among men and its early detection is critical for its successful treatment. The use of multimodal imaging, such as MR-PET, is most advantageous as it is able to provide detailed information about the prostate. However, as the human prostate is flexible and can move into different positions under external conditions, it is important to localise the focused region-of-interest using both MRI and PET under identical circumstances. In this work, we designed five commonly used linear and quadrature radiofrequency surface coils suitable for hybrid MR-PET use in endorectal applications. Due to the endorectal design and the shielded PET insert, the outer face of the coils investigated was curved and the region to be imaged was outside the volume of the coil. The tilting angles of the coils were varied with respect to the main magnetic field direction. This was done to approximate the various positions from which the prostate could be imaged. The transmit efficiencies and safety excitation efficiencies from simulations, together with the signal-to-noise ratios from the MR images were calculated and analysed. Overall, it was found that the overlapped loops driven in quadrature were superior to the other types of coils we tested. In order to determine the effect of the different coil designs on PET, transmission scans were carried out, and it was observed that the differences between attenuation maps with and without the coils were negligible. The findings of this work can provide useful guidance for the integration of such coil designs into MR-PET hybrid systems in the future.}, language = {en} } @article{Stulpe2020, author = {Stulpe, Werner}, title = {Pairwise coexistence of effects versus coexistence}, series = {Journal of Physics: Conference Series}, volume = {1638}, journal = {Journal of Physics: Conference Series}, number = {012004}, publisher = {IOP}, address = {Bristol}, issn = {1742-6596}, doi = {10.1088/1742-6596/1638/1/012004}, pages = {1 -- 21}, year = {2020}, language = {en} }