Brookhaven, December 3rd, 1998
1. Slow Current Integrator for the cell intercalibration and long term monitoring of the Tile Calorimeter. (PS Format). This note offers an overview of the specifications and of the achieved performance.
2. Slow Current Integrator. Downloadable schematic (PS Format). This schematic represents the slow integrator implementation in he 3in1 card. A complete diagram of the 3in1 card is available. The proposed diagram was succesfully tested and its radiation tolerance is currently being tested.
3. Slow Integrators Gain Dispersion within a superdrawer (1997 data). The six programable transimpedance calibrations are in agreement with the expected tolerances. Pedestals Dispersion within the same superdrawer. The pedestal dispersion is function of the operational amplifiers offset voltage distributions and also of the selected gain. High gains show big dispersions. The pedestal appeared to be stable in long term periods.
4. Readout Interface. A protoype was developped for the 1998 testbeam and tested succesfully. A CANbus link is used and exhibited a throughput wide enough to transmit 9.6Kbps over 100 m at the maximum cesium source speed of 30 cm/s. A final version is under development that will incoprorate radiation tolerant components and will support in system programability. A CAN protocol as DeviceNet or CANOpen is foreseen as Application Protocol. Connectors, Input stage and digitizer, Pedestal Control, CAN port and Microcontroller schematics.
5. The described system was used to monitor the optics response over 250 days. An intial downdrift period attributed to the photomultiplier was observed in the first 100 days, while after this downdrift period the cesium source decay can be observed also. The system exhibits a resolution better than 1% and a long term stability that allows to monitor the stability of other calorimeter elements.
6. Download the PowerPoint97 presentation show file.