23–27 Sept 2013
Perugia, IT
Europe/Zurich timezone

An Ultra-Fast Data Acquisition System for Coherent Synchrotron Radiation with YBCO Terahertz Detectors

24 Sept 2013, 18:14
1m
Perugia, IT

Perugia, IT

<font face="Verdana" size="2.5">Congress center Giò Via R. D'Andreotto, 19 06124 Perugia (PG) Italy
Poster Poster

Speaker

Michele Caselle (Karlsruhe Institute of Technology)

Description

The recording of coherent synchrotron radiation requires DAQ systems with high temporal resolution. To resolve ultra-short terahertz pulses emitted by single bunch YBCO superconducting thin film detectors have been developed. A novel data acquisition system for sampling of the individual ultra-short terahertz pulses with high accuracy and real-time data processing is presented. The DAQ system is designed to sample the fast pulse signals with sampling times down to 3 ps. The data acquisition and the terahertz YBCO detectors have been tested at the synchrotron ANKA at KIT. The concept and the first results with single and multi-bunch filling pattern are discussed.

Summary

Since a few years coherent synchrotron radiation (CSR) generated by short electron bunches is provided at the ANKA light source. Electron bunches can be filled in up to 184 buckets with a distance between two adjacent bunches of 2 ns corresponding to the RF system frequency of 500 MHz. Arbitrary filling patterns can be used to study the interaction of adjacent bunches in CSR. To detect and study the THz emission characteristics of CSR over multiple revolutions a detector system based on thin YBa2Cu3O7−δ (YBCO) superconductor film detectors can be used. The intrinsic response time of YBCO thin films is only a few picoseconds and allows one to resolve the signal of individual bunches even within a multi-bunch environment. Response transients excited by CSR THz pulses as short as 17 ps has been determined as the FWHM at the output. A novel system for fast and continuous sampling of the individual ultra-short terahertz pulses has been developed. The setup is accomplished by real-time data processing based on high-end graphics processing units (GPUs). The data acquisition system consists of detector, low-noise amplifier, fast pulse sampling FMC board, readout board and the readout PC. The analog output of the low noise amplifier operating at ambient temperature is connected to the fast sampling board. Four samples are recorded in parallel for each terahertz pulse with programmable sampling times in the range of 3 to 100 ps. The readout board provides programmable logic (FPGA) and large memories for on-line data processing and temporary storage. The FPGA performs an on-line pulse reconstruction and calculates both the peak amplitude of each pulse and the time between consecutive bunches with a picosecond time resolution using fast waveform sampling technics. Finally, the data is transmitted to the readout computer. The readout interface is realized by a bus master DMA engine connected to PCI Express endpoint logic to ensure a high data throughput of up to 2 GByte/s. The fast pulse sampling board and the high data throughput board have been tested with terahertz YBCO detectors at ANKA. Multi-turn measurements of CSR have turned out to be an important diagnostic tool for storage rings with short bunch operation. With the DAQ system it is possible to resolve the bursting behavior of single bunches even in a multi-bunch environment to study the bunch-bunch-interactions.

Primary author

Michele Caselle (Karlsruhe Institute of Technology)

Co-authors

Dr Andreas Kopmann (KIT-IPE) Dr Anke-Susanne Müller (KIT-IPS) Prof. Marc Weber (KIT-IPE) Dr Matthias Hofherr (KIT-IMS) Prof. Michael Siegel (KIT-IMS) Dr Nigel John Smale (KIT-ANKA) Dr Petra Thoma (KIT-IMS) Dr Suren Cilingaryan (KIT-IPE) Dr Vitali Judin (IPE-ANKA) Dr Wünsch Stefan (KIT-IMS)

Presentation materials