Title :
A 40 MHz pipelined trigger for K0→2π0 decays for the CERN NA48 experiment
Author :
Gorini, B. ; Avanzini, C. ; Barr, G.D. ; Calafiura, P. ; Cirilli, M. ; Costantini, F. ; Cundy, D. ; Dibon, H. ; Fischer, G. ; Formenti, F. ; Hallgren, B. ; Iwanski, W. ; Jeitler, M. ; Kapusta, P. ; Laico, F. ; Laverriere, G. ; Magazza, G. ; Markytan, M. ;
Author_Institution :
Ist. Nazionale di Fisica Nucl., Pisa, Italy
fDate :
8/1/1998 12:00:00 AM
Abstract :
A first level trigger system based on a 40 MHz digital pipeline has been developed for the CERN NA48 experiment, aiming at measuring CP violation in K0→2π decays. The outputs of the 13340 cells of the 10 m3 liquid krypton calorimeter are summed into 64 X and 64 Y projection strips and continuously digitised with 40 MHz FADCs. This information is used to reconstruct at each clock cycle and for the two calorimeter projections, the number of clusters, the impact time of each of them (with a precision of about 3 ns), their total energy and the first and second moments of the energy distribution. Based on the quantities listed above, a programmable look-up table system subsequently computes online the longitudinal position of the kaon decay vertex and performs an event selection. The system is described
Keywords :
analogue-digital conversion; calorimeters; energy loss of particles; high energy physics instrumentation computing; liquid scintillation detectors; nuclear electronics; pipeline processing; real-time systems; trigger circuits; 40 MHz; CERN NA48 experiment; CP violation; FADC; calorimeter projections; digital pipeline; energy distribution; event selection; first level trigger system; kaon decay vertex; kaon0 decay into pion0+pion0; liquid Kr calorimeter; longitudinal position; pipelined trigger; programmable lookup table system; projection strips; Buffer storage; Clocks; Collaboration; Detectors; Geometry; Mesons; Pipelines; Statistics; Strips; Table lookup;
Journal_Title :
Nuclear Science, IEEE Transactions on
