@article{StreunBrandenburgLarueetal.2002,
  author    = {Streun, M. and Brandenburg, G. and Larue, H. and Zimmermann, E. and Ziemons, Karl and Halling, H.},
  title     = {A PET system based on data processing of free-running sampled pulses},
  series = {2001 IEEE Nuclear Science Symposium Conference Record, Vol. 2},
  journal   = {2001 IEEE Nuclear Science Symposium Conference Record, Vol. 2},
  issn      = {1082-3654},
  pages     = {693 -- 694},
  year      = {2002},
  abstract  = {Within the developments for the Crystal Clear small animal PET project (CLEARPET) a dual head PET system has been established. The basic principle is the early digitization of the detector pulses by free running ADCs. The determination of the γ-energy and also the coincidence detection is performed by data processing of the sampled pulses on the host computer. Therefore a time mark is attached to each pulse identifying the current cycle of the 40 MHz sampling clock. In order to refine the time resolution the pulse starting time is interpolated from the samples of the pulse rise. The detector heads consist of multichannel PMTs with a single LSO scintillator crystal coupled to each channel. For each PMT only one ADC is required. The position of an event is obtained separately from trigger signals generated for each single channel. An FPGA is utilized for pulse buffering, generation of the time mark and for the data transfer to the host via a fast I/O-interface.},
  language  = {en}
}
@article{StreunBrandenburgLarueetal.2001,
  author    = {Streun, M. and Brandenburg, G. and Larue, H. and Zimmermann, E. and Ziemons, Karl and Halling, H.},
  title     = {Pulse recording by free-running sampling},
  series = {IEEE Transactions on Nuclear Science},
  volume    = {48},
  journal   = {IEEE Transactions on Nuclear Science},
  number    = {3},
  isbn      = {0018-9499},
  pages     = {524 -- 526},
  year      = {2001},
  abstract  = {Pulses from a position-sensitive photomultiplier (PS-PMT) are recorded by free-running ADCs at a sampling rate of 40 MHz. A four-channel acquisition board has been developed which is equipped with four 12-bit ADCs connected to one field programmable gate array (FPGA). The FPGA manages data acquisition and the transfer to the host computer. It can also work as a digital trigger, so a separate hardware trigger can be omitted. The method of free-running sampling provides a maximum of information, besides the pulse charge and amplitude also pulse shape and starting time are contained in the sampled data. This information is crucial for many tasks such as distinguishing between different scintillator materials, determination of radiation type, pile-up recovery, coincidence detection or time-of-flight applications. The absence of an analog integrator allows very high count rates to be dealt with. Since this method is to be employed in positron emission tomography (PET), the position of an event is also important. The simultaneous readout of four channels allows localization by means of center-of-gravity weighting. First results from a test setup with LSO scintillators coupled to the PS-PMT are presented here},
  language  = {en}
}
@article{StreunBrandenburgLarueetal.2000,
  author    = {Streun, M. and Brandenburg, G. and Larue, H. and Zimmermann, E. and Ziemons, Karl and Halling, H.},
  title     = {Pulse recording by free-running sampling},
  series = {2000 IEEE Nuclear Science Symposium Conference Record, Vol. 2},
  journal   = {2000 IEEE Nuclear Science Symposium Conference Record, Vol. 2},
  issn      = {1082-3654},
  pages     = {9/179 -- 9/181},
  year      = {2000},
  abstract  = {Pulses from a position-sensitive photomultiplier (PS-PMT) are recorded by free running ADCs at a sampling rate of 40 MHz. A four-channel acquisition-board has been developed which is equipped with four 12 bit-ADCs connected to one FPGA (field programmable gate array). The FPGA manages data acquisition and the transfer to the host computer. It can also work as a digital trigger, so a separate hardware-trigger can be omitted. The method of free running sampling provides a maximum of information, besides the pulse charge and amplitude also pulse shape and starting time are contained in the sampled data. These informations are crucial for many tasks such as distinguishing between different scintillator materials, determination of radiation type, pile-up recovery, coincidence detection or time-of-flight applications. The absence of an analog integrator allows coping with very high count rates. Since this method is going to be employed in positron emission tomography (PET), the position of an event is another important information. The simultaneous readout of four channels allows localization by means of center-of-gravity weighting. First results from a test setup with LSO-scintillators coupled to the PS-PMT are presented},
  language  = {en}
}