@article{StreunChavanLameetal.2006,
  author    = {Streun, M. and Chavan, U. and Lame, H. and Parl, C. and M{\"u}ller-Veggian, Mattea and Ziemons, Karl},
  title     = {Treating the Gain Non-Uniformity of Multi Channel PMTs by Channel-Specific Trigger Levels},
  series = {2006 IEEE Nuclear Science Symposium Conference Record, Vol. 2.},
  journal   = {2006 IEEE Nuclear Science Symposium Conference Record, Vol. 2.},
  address   = {San Diego, CA},
  issn      = {1082-3654},
  pages     = {1301 -- 1304},
  year      = {2006},
  language  = {en}
}
@article{StreunBrandenburgLarueetal.2006,
  author    = {Streun, M. and Brandenburg, G. and Larue, H. and Parl, C. and Ziemons, Karl},
  title     = {The data acquisition system of ClearPET neuro - a small animal PET scanner},
  series = {IEEE Transactions on Nuclear Science},
  volume    = {53},
  journal   = {IEEE Transactions on Nuclear Science},
  number    = {3},
  isbn      = {0018-9499},
  pages     = {700 -- 703},
  year      = {2006},
  abstract  = {The Crystal Clear Collaboration has developed a modular system for a small animal PET scanner (ClearPET). The modularity allows the assembly of scanners of different sizes and characteristics in order to satisfy the specific needs of the individual member institutions. The system performs depth of interaction detection by using a phoswich arrangement combining LSO and LuYAP scintillators which are coupled to Multichannel Photomultipliers (PMTs). For each PMT a free running 40 MHz ADC digitizes the signal and the complete scintillation pulse is sampled by an FPGA and sent with 20 MB/s to a PC for preprocessing. The pulse provides information about the gamma energy and the scintillator material which identifies the interaction layer. Furthermore, the exact pulse starting time is obtained from the sampled data. This is important as no hardware coincidence detection is implemented. All single events are recorded and coincidences are identified by software. The system in J{\"u}lich (ClearPET Neuro) is equipped with 10240 crystals on 80 PMTs. The paper will present an overview of the data acquisition system.},
  language  = {en}
}
@article{KhodaverdiWeberStreunetal.2006,
  author    = {Khodaverdi, M. and Weber, S. and Streun, M. and Parl, C. and Ziemons, Karl},
  title     = {High resolution imaging with ClearPET™ Neuro - first animal images},
  series = {2005 IEEE Nuclear Science Symposium Conference Record, Vol. 3},
  journal   = {2005 IEEE Nuclear Science Symposium Conference Record, Vol. 3},
  isbn      = {1082-3654},
  pages     = {1641 -- 1644},
  year      = {2006},
  abstract  = {The ClearPET™ Neuro is the first full ring scanner within the Crystal Clear Collaboration (CCC). It consists of 80 detector modules allocated to 20 cassettes. LSO and LuYAP:Ce crystals in phoswich configuration in combination with position sensitive photomultiplier tubes are used to achieve high sensitivity and realize the acquisition of the depth of interaction (DOI) information. The complete system has been tested concerning the mechanical and electronical stability and interplay. Moreover, suitable corrections have been implemented into the reconstruction procedure to ensure high image quality. We present first results which show the successful operation of the ClearPET™ Neuro for artefact free and high resolution small animal imaging. Based on these results during the past few months the ClearPET™ Neuro System has been modified in order to optimize the performance.},
  language  = {en}
}
@article{StreunBrandenburgKhodaverdietal.2006,
  author    = {Streun, M. and Brandenburg, G. and Khodaverdi, M. and Larue, H. and Parl, C. and Ziemons, Karl},
  title     = {Timemark correction for the ClearPET™ scanners},
  series = {2005 IEEE Nuclear Science Symposium Conference Record, Vol. 4},
  journal   = {2005 IEEE Nuclear Science Symposium Conference Record, Vol. 4},
  isbn      = {1082-3654},
  pages     = {2057 -- 2060},
  year      = {2006},
  abstract  = {The small animal PET scanners developed by the Crystal Clear Collaboration (ClearPETtrade) detect coincidences by analyzing timemarks which are attached to each event. The scanners are able to save complete single list mode data which allows analysis and modification of the timemarks after data acquisition. The timemarks are obtained from the digitally sampled detector pulses by calculating the baseline crossing of the rising edge of the pulse which is approximated as a straight line. But the limited sampling frequency causes a systematic error in the determination of the timemark. This error depends on the phase of the sampling clock at the time of the event. A statistical method that corrects these errors will be presented},
  language  = {en}
}