Institute for Safety Research Dávid Légrády IP-EUROTRANS ITC2 Development of a Neutron Time-of-Flight Source at the ELBE Accelerator ELBE Neutron source Collimator Beam characteristics Detector development Institute of Nuclear and Hadron Physics and Institute of Safety Research, Forschungszentrum Rossendorf, Dresden Institute of Nuclear and Particle Physics, Technische Universität Dresden J. Klug, E. Altstadt, C. Beckert, R. Beyer, H. Freiesleben, V. Galindo, M. Greschner, E. Grosse, A. R. Junghans, D. Légrády, B. Naumann, K. Noack, R. Schlenk, S. Schneider, K. Seidel, A. Wagner, F.-P. Weiss

Institute for Safety Research Dávid Légrády IP-EUROTRANS ITC2 PhD: 2005, Reactor Institute Delft, Delft University of Technology, The Netherlands Thesis:The Time Dependent Midway Monte Carlo Method for Borehole Logging Applications Currently working at: Forschungszentrum Rossendorf,Institute of Safety Research, Dresden, Germany Current Research Areas: Time Dependent Monte Carlo for Reactor Dynamics variance reduction optimisation for the collimator of the ELBE nToF setup detector simulations for the nTof measurements Connection to EUROTRANS: Future contributor ADS simulations About Me

Institute for Safety Research Dávid Légrády IP-EUROTRANS ITC2 ELBE: Electron Linear accelerator with high Brilliance and low Emittance The superconducting electron accelerator ELBE E e ≤ 40 MeV I e ≤ 1 mA Micropulse duration  t = 5 ps f = 0.5–1 MHz

Institute for Safety Research Dávid Légrády IP-EUROTRANS ITC2 The liquid-lead radiator Electron beam pulse length  t = 5 ps Small neutron radiator volume  - short neutron pulses, well-determined  in time by e - beam time structure  - minimize scattering in radiator &  thermal neutron background Large enough for reasonable intensity  - optimal volume  1 cm 3 - neutron pulse width < 2 ns - E n resol  E/E < 1 % at 4 m flight path Thermal load up to 25 kW  liquid Pb radiator Water-cooled via InGaSn heat exchanger

Institute for Safety Research Dávid Légrády IP-EUROTRANS ITC2 Neutron fluxes obtained with I e = 1 mA MCNP simulations E e MeV From rad. s -1 At det., 4 m cm -2 s · · · · · ·10 7

Institute for Safety Research Dávid Légrády IP-EUROTRANS ITC2 Neutron beam profile for different collimators MCNP simulations; E e = 30 MeV, I e = 1 mA 2.4 m normal heavy borated concrete concrete PE lead beam cyl. hole, Ø 3 cm conical Radial distance from center / cm Flux density / cm -2 s -1

Institute for Safety Research Dávid Légrády IP-EUROTRANS ITC2 Neutron fluxes, pulse overlap without/with filter f = 500 kHz 180 ns, 2.5 MeV & 2.18  s,  20 keV Present pulse / previous, no filter: 5·10 2 with filter: 1·10 4

Institute for Safety Research Dávid Légrády IP-EUROTRANS ITC2 Time-of-flight vs. energy 96 % in peak  t = 0.1 ns  E n = 1 keV

Institute for Safety Research Dávid Légrády IP-EUROTRANS ITC2 Detector development BaF 2 l = 19 cm Ø = 53 mm  : 80 % of 4  sr slow & fast component  pulse shape discr 60 Co source   E/E  12 % at 1 MeV time resol  640 ps Plastic scintillators l = 1 m Large np scattering cross sec Good timing resolution  detection point from two- sided readout < 1 MeV: Li-glass 6 Li(n,t)  Photons Neutrons n 

Institute for Safety Research Dávid Légrády IP-EUROTRANS ITC2 Detector development time / ns counts neutron detection efficiencies share of events with lost timing info due to neutron scattering before detection 25 mm Li-glass 11 mm plastic threshold 5 keV 34 % 15 % Eff = 1.6 % Eff = 56 % Simulations: E n = 144 keV: no condition coincidence in PMTs anticoincidence counts QDC channel Plastic scintillator detectors: single-electron peak observed by coincident readout of PM tubes  neutron detection threshold of 5–10 keV ( 252 Cf source)

Institute for Safety Research Dávid Légrády IP-EUROTRANS ITC2 Summary New neutron ToF setup – liquid Pb radiator at ELBE Compact system – 5 ps e - pulses, 4 m flight path  E/E < 1 % Neutron intensity 1.5·10 7 cm -2 s keV < E n < 10 MeV Assembly in progress Test runs of the radiator  & n detectors ready for calibration e - n