TY  - JOUR
A1  - Bussmann, N.
A1  - Engels, R.
A1  - Fuss, L.
A1  - Kemmerling, G.
A1  - Reinartz, R.
A1  - Langen, K.-J.
A1  - Schelten, J.
A1  - Ziemons, Karl
T1  - Performance measurement of a new high resolution detector system for I-131 thyroid studies
JF  - 2000 IEEE Nuclear Science Symposium Conference Record, Vol. 3
N2  - A 2-dimensional detector system for high resolution thyroid I-131 scintigraphy was developed. It has a sensitive area of 4 cm×4 cm and consists of a lead-collimator and an array of 10×10 EGO crystals combined with a position sensitive photomultiplier. The spatial resolution and the sensitivity of the detector has been measured and compared to two commercially available gamma-cameras. Furthermore first patient measurements have been carried out
Y1  - 2000
SN  - 1082-3654
SP  - 22/35
EP  - 22/37
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  - 2000 IEEE Nuclear Science Symposium Conference Record, Vol. 2
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 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
Y1  - 2000
SN  - 1082-3654
SP  - 9/179
EP  - 9/181
ER  -