TY - CPAPER
AU - Caselle, C.M.
AU - Brosi, M.
AU - Chilingaryan, S.A.
AU - Dritschler, T.
AU - Hiller, N.
AU - Judin, V.
AU - Kopmann, A.
AU - Müller, A.-S.
AU - Petzold, L.
AU - Raasch, J.
AU - Rota, L.
AU - Siegel, M.
AU - Smale, N.J.
AU - Steinmann, J.L.
AU - Vogelgesang, M.
AU - Weber, M.
AU - Wuensch, S.
TI - A Picosecond Sampling Electronic “KAPTURE” for Terahertz Synchrotron Radiation
J2 - Proc. of IBIC2014
AB - For a few years, coherent synchrotron radiation (CSR) generated by short electron bunches has been 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 are generated to investigate the interaction of adjacent bunches in CSR. To study the THz emission characteristics over multiple revolutions superconducting YBa2Cu3O7−δ (YBCO) film detectors are used. The intrinsic response time of YBCO thin films is in the order of a few picoseconds only. For fast, continuous sampling of these individual ultra-short terahertz pulses, a novel digitizer system has been developed. The KAPTURE (KArlsruhe Pulse Taking Ultra-fast Readout Electronics) consists of a wideband low-noise amplifier, a picosecond pulse sampling card and a GByte transfer data link back-end readout card. High-end graphic processing units (GPUs) perform real-time data analysis. The KAPTURE system was successfully demonstrated for readout of the intensity fluctuations in the CSR at the ANKA Storage Ring detected in THz range. Four samples are recorded in parallel for each fast pulse with programmable sampling times in the range of 3 to 100 psec. A clean jitter phase locked loop (PLL) provides a clock signal with high temporal accuracy. The back-end card receives the 4 digital samples every 2 ns with 12 bits resolution and transmits the data to the data analysis unit. The readout board is based on programmable logic FPGA and DDR3 memories for on-line data preprocessing and temporary storage. The data is transmitted to the GPU computing node by a fast data transfer links based on a bus master DMA engine connected to PCI express endpoint logic to ensure a continuous high data throughput of up to 4 GByte/s. This heterogeneous real-time system architecture based on FPGA and GPU is used for on-line pulse reconstruction and evaluations and calculates the peak amplitude of each pulse and the time between consecutive bunches with a picosecond time resolution. A Fast Fourier Transform (FFT) is performed on-line for the frequency analysis of the CSR undulations. With the presented acquisition system it was possible to resolve the bursting behavior of single bunches even in a multi-bunch environment to study the bunch-bunch-interactions at ANKA. First results obtained have already been published in the synchrotron machine physic community. The monitoring of bursting for different ANKA parameters using KAPTURE system opens up new analysis and diagnostics possibilities for electron storage rings operating at short bunch lengths.
PB - JACoW
CY - Geneva, Switzerland
SP - 24
EP - 28
KW - synchrotron-radiation
KW - synchrotron
KW - radiation
KW - storage-ring
KW - detector
DA - 2014/10
PY - 2014
SN - 978-3-95450-141-0
UR - http://jacow.org/IBIC2014/papers/moczb1.pdf
ER -