Once the signal has been modulated to RF, passed through the microwave multiplexer, and has been modulated back to base band, the signal is digitized by an ADC board. The tones are generated in the FPGA by storing a large lookup table in Quad Data Rate (QDR) SRAM modules and playing out the waveform to a DAC board. The FPGA is used to generate multiple tones in base band, from more » 10MHz to 250MHz, which are subsequently mixed to RF in the multiple GHz range and sent through the microwave multiplexer. The combination of a ROACH board, ADC/DAC conversion daughter boards, and hardware for RF mixing allows for the generation and capture of multiple RF tones for reading out microwave multiplexed x-ray TES microcalorimeters. ![]() ROACH is an open-source hardware and software platform featuring a large Xilinx Field Programmable Gate Array (FPGA), Power PC processor, several 10GB Ethernet SFP+ interfaces, and a collection of daughter boards for analog signal generation and acquisition. ![]() We are developing room temperature electronics based upon the ROACH platform for reading out microwave multiplexed X-ray TES. Both of the blocks are compiled in low-cost FPGA and their silicon resource usages are low. An additional factor of 10 compression ratio is achieved using the Dynamic Decimation scheme on the BO detector data, making a total compression rate of approximate 100 when the Dynamic Decimation and the Huffman Coding functional blocks are cascaded. Note that unlike in typical zerosuppression schemes, in Dynamic Decimation, the data in the pedestal region are not thrown away but kept at a lower sampling rate. In the Dynamic Decimation scheme, data are sampled at the full sampling rate in the regions-of-interest (ROI) containing waveforms of track-hits and are decimated down to lower sampling rate outside the ROI. Another scheme, Dynamic Decimation, has been developed to compress further the potential supernova data so that the storage can be implemented within a reasonable budget. In addition to accelerator neutrino data, which comes with small duty cycle in sync with the accelerator beam spill, continuous digitized waveforms are to be temporarily stored in the MicroBooNE data-acquisition system for about an hour, long enough for an external alert from possible supernova events. ![]() The compressed data can be fully recovered back to the original data since the compression is lossless. For sense wire more » waveforms produced by cosmic ray tracks, the Huffman Coding scheme compresses the data by a factor of approximately 10. We have developed a lossless data reduction scheme based on Huffman Coding and have tested the scheme on cosmic ray data taken from a small liquid Argon time projection chamber, the BO detector. The waveforms of the 9000 sense wires in the chamber are continuously digitized at 2 M samples/s - which results in a large volume of data coming off the TPC. MicroBooNE is a liquid Argon time projection chamber to be built at Fermilab for an accelerator-based neutrino physics experiment and as part of the R&D strategy for a large liquid argon detector at DUSEL.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |