TY  - CHAP
A1  - Peters, H.
A1  - Ziemons, Karl
A1  - Dammers, J.
A1  - Müller-Veggian, Mattea
ED  - Nenonen, Jukka
T1  - Continuous head motion detection during MEG measurement using head location coils
T2  - Proceedings of the 12th International Conference on Biomagnetism : August 13 - 17, 2000, Helsinki University of Technology, Espoo, Finland
Y1  - 2001
SN  - 951-22-5401-8
N1  - Biomag <12, 2000, Espoo> ; Teknillinen Korkeakoulu <Helsinki> ; International Conference on Biomagnetism <12, 2000, Espoo>
PB  - Helsinki Univ. of Technology, Laboratory of Biomedical Engineering
CY  - Espoo
ER  - 
TY  - JOUR
A1  - Streun, M.
A1  - Brandenburg, G.
A1  - Larue, H.
A1  - Zimmermann, E.
A1  - Ziemons, Karl
A1  - Halling, H.
T1  - Pulse recording by free-running sampling
JF  - IEEE Transactions on Nuclear Science
N2  - 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
Y1  - 2001
SN  - 0018-9499
VL  - 48
IS  - 3
SP  - 524
EP  - 526
ER  -