Ana Fernandes Real-time tools and algorithms for gamma spectroscopy Doctorate in Fusion Science and Engineering | IPP Garching | Sept. 30 th, 2009

OUTLINE  Gamma-Ray JET;  Real time algorithms;  Tests; Results; Conclusions;  The DAQ system for the upgrade program;  My tasks;  Future Work. Doctorate in Fusion Science and Engineering | IPP Garching | Sept. 30 th, 2009

GAMMA-RAY SPECTROSCOPY  identify nuclear reactions  distinguish fast-ion species in plasma  Infer their temperatures and densities When fast ions : React with : intense γ-ray emission produced γ-ray energy spectra Fusion products ICRF-driven ions NBI-injected ions  Plasma fuel ions  Plasma impurities allows to: Doctorate in Fusion Science and Engineering | IPP Garching | Sept. 30 th, 2009

JET GAMMA-RAY DIAGNOSTICS  Horizontal & vertical neutron/ gamma Camera Spatial distribution of the gamma-ray emission  Two array of collimators (CsI(T1) photo-diode, each LOS)  Tomographic reconstruction of the Gamma-ray emissivity  Tomographic reconstruction of the Gamma-ray emissivity  Limitations: Count rate => obsolete electronics modules used for analog processing and DAQ  Limitations: Count rate => obsolete electronics modules used for analog processing and DAQ Doctorate in Fusion Science and Engineering | IPP Garching | Sept. 30 th, 2009

γ -Ray Energy Spectra  Horizontal view of the plasma  Vertical view of the plasma JET GAMMA-RAY DIAGNOSTICS count rate; detector response; energy resolution; Limitations New gamma spectrometers for: high energy resolution; high efficiency; high rate with large detection crystal NaI(TI) scintilator detector BGO scintilator detector Doctorate in Fusion Science and Engineering | IPP Garching | Sept. 30 th, 2009

IPFN(IST) TEAM TASK DAQ system => will replace the current electronics used for the JET Gamma ray diagnostics  Capable to perform high-resolution gamma spectroscopy at very high count rate (few MHZ)  Capable to perform real time algorithms for data reduction and digital pulse processing (PHA with PUR)  To fully exploit the flux increase provided by future high power experiments at JET and ITER Doctorate in Fusion Science and Engineering | IPP Garching | Sept. 30 th, 2009

ATCA SHELF CONTROLER TRANSIENT RECORD MODULE THE DAQ SYSTEM 8 channels with : 4GB DDR2 SDRAM 2 FPGA (XC4VFX ) 400 MSamples/s (ADS5474) or 250 MSamples/s (ADS5444) Doctorate in Fusion Science and Engineering | IPP Garching | Sept. 30 th, 2009

MY TASKS  Fulfill the demanded operational requirements; Design and development of the FPGA code (FIRMWARE) for the TR module to:  Perform REAL TIME ALGORITHMS FOR PULSE FPGA Doctorate in Fusion Science and Engineering | IPP Garching | Sept. 30 th, 2009

FPGA MAIN TASKS  Receive data from ADCS  Configure clocks  Interface to local memory  Perform gigabit communication through PCIe links  Manage local memory data storage and reading  Manage the trigger modes  Process Data Doctorate in Fusion Science and Engineering | IPP Garching | Sept. 30 th, 2009

FPGA BLOCKS DIAGRAM Doctorate in Fusion Science and Engineering | IPP Garching | Sept. 30 th, 2009

 Compiler: ISE (XILINX)  Compiler: ISE (XILINX)  Code Language: Verilog CODE AND COMPILER Doctorate in Fusion Science and Engineering | IPP Garching | Sept. 30 th, 2009

FPGA OPERATING MODES (1) Raw data mode (2) Pulse storage mode (3) Processed data mode Data reduction/processing: Raw Data 400MSPS => 2.5 seconds Processed 2Mevents/s => ~ 2 minutes!! To fill 2GB memory with 1 channel: Great for long shots Doctorate in Fusion Science and Engineering | IPP Garching | Sept. 30 th, 2009 (pulse + TSTAMP) ( pulse energy + TSTAMP ) Real Time Algorithms Novelty should work with Parallelized Data

ALGORITHMS FOR PARALLEL DATA  High sampling rate Data parallelized  Interleave channels sampled at ¼ of the sampling rate Doctorate in Fusion Science and Engineering | IPP Garching | Sept. 30 th, 2009

PULSE STORAGE ALGORITHM Parameters Example: PTRG =16, PWIDTH =128 Doctorate in Fusion Science and Engineering | IPP Garching | Sept. 30 th, 2009

PULSE PROCESSING ALGORITHM  Should be used in step signals  Ability to perform pulse processing regarding parallel data as if it was in series  Based on the conventional time- invariant digital trapezoidal shaper (DTS) Doctorate in Fusion Science and Engineering | IPP Garching | Sept. 30 th, 2009

PULSE PROCESSING ALGORITHM (DTS) DTS MODULE (1/2) delay-subtract units k=0:15,k+1 L=0:255,L+4 Rising (falling) Edge => K (~decay time constant τ) Trapezoidal Shape Flat Top => |L-K|(~1/3 of τ) Doctorate in Fusion Science and Engineering | IPP Garching | Sept. 30 th, 2009

PULSE PROCESSING ALGORITHM (DTS) DTS MODULE (2/2) 1 st Accumulator pole-zero cancelation ~ τ 2 nd Accumulator High Pass Deconvolver (HPD) Accumulator (HPD) TRAPEZOIDAL SHAPE Doctorate in Fusion Science and Engineering | IPP Garching | Sept. 30 th, 2009

PULSE PROCESSING ALGORITHM (ER) ED MODULE When Threshold TRIGGER EVENT Doctorate in Fusion Science and Engineering | IPP Garching | Sept. 30 th, 2009

PULSE PROCESSING ALGORITHM (ED) Inputs ED(t) ER (16-bit) + T_STAMP (48-bit) 64-bit output S n (t)  If  ER = E - B  E = flat top  B = baseline  Resolver starts  If ER MODULE Doctorate in Fusion Science and Engineering | IPP Garching | Sept. 30 th, 2009

PULSE PROCESSING RESULTS Tests with AWG420 Pulse event (raw k=8, l=24 Trapezoid (calibration mode) Doctorate in Fusion Science and Engineering | IPP Garching | Sept. 30 th, 2009

PULSE PROCESSING RESULTS  Conventional digital trapezoidal shaper validity is ensured! FWHM =2,64 (400k events) Parallel Processing FPGA results =>obtained for single energy pulse plus noise Compared with results from not parallelized standard PC Doctorate in Fusion Science and Engineering | IPP Garching | Sept. 30 th, 2009

 Processing operating method => increase in the number of useful stored data To prevent data losses due to high sampling rate To provide interleaved architectures between channels Parallelized Processing Method May be used as interface to other algorithms  Classical filter validity is ensured using the parallelized method!  Work presented in a Talk at the IAEA conference, June 2009 PULSE PROCESSING CONCLUSIONS Doctorate in Fusion Science and Engineering | IPP Garching | Sept. 30 th, 2009

PULSE PROCESSING NEXT STEPS Baseline restorationthe performance of this filter drops if the signal baseline is not stable Pulse pile up discriminatorPile-up rejection with the current algorithm Improve/change the algorithm to perform: Less pulse shape dependencyThe JET GRS current photomultiplier makes the rise time of pulses slower use the parallelized method with other pulse processing algorithms The algorithm performance drops Doctorate in Fusion Science and Engineering | IPP Garching | Sept. 30 th, 2009

REFERENCES AdvancedTCA®, PICMG® 3.0 Revision 2.0, AdvancedTCA® Base Specification, March 18, A. J. N. Batista, J. Sousa, and C. A. F. Varandas, ATCA digital controller hardware for vertical stabilization of plasmas in tokamaks, Review of Scientific Instruments, 77, no. 10 (2006). R.C. Pereira J.Sousa, A.M. Fernandes, F. Patrício, B. Carvalho, A.Neto, C.A.F. Varandas, G. Gorini, M. Tardocchi, D.Gin, A. Shevelev, ATCA data acquisition system for gamma ray spectrometry, Journal of Fusion Engineering and Design 83 (2008) 341–345. V.G.Kiptily et al.,  -ray diagnostics of energetic ions in JET, Nuclear Fusion 42, (2002), ; V.T. Jordanov, Glenn F. Knoll, Digital synthesis of pulse shapes in real time for high resolution radiation spectroscopy, Nuclear Instrum. Meth. Phys. Res. A 345 (1994) M. Tardocchi et al, Gamma ray spectroscopy at high energy and high time resolution at JET, Rev. of Scientific Instruments, 79 (2008) 10E524. V.T. Jordanov et al, Digital techniques for real-time pulse shaping in radiation measurements, Nuclear Instrum. Meth. Phys. Res. A 353 (1994) 261–264. Doctorate in Fusion Science and Engineering | IPP Garching | Sept. 30 th, 2009