Performance of the new high flux neutron source FRM-II IGORR10, Gaithersburg, 13. September 2005 Physics Department FRM-II Winfried Petry, Technische Universität München

29. April st nuclear license 1. August 1996begin of construction 13. October nd nuclear license 2. May rd nuclear license 2. March 2004first neutrons 21. October 2004commissioning finished, 52 full power days of 20 MWatt December st Proposal round 29. April 2005 begin routine operation at 20 MWatt August nd proposal round today3 rd cycle finished, FRM-II has started its routine operation !

Neutrons, how & where?

FRM-II, the principle

Fuel element control rod Beryllium zone cooling gap fuel plate channel for fuel element outer tube of fuel element inner tube of fuel element 8 kg 235 Uranium 52 days fuel cycle mm 229 mm 130 mm 118 mm aktive Zone

Unperturbed flux distribution in FRM II high [cm] radius [cm] cold-, hot-source, converter, beam tubes cause depression  flux depression by 20%  6.4 –6.5 x n/cm 2 s at beam hole positions

Cut through the reactor containment cold neutrons neutron guide fast neutrons tumor therapy radiology hot neutrons thermal neutrons fission products ultra cold neutrons thermal positrons

Neutron guide hall atom egg neutron guide hallexperimental hall second neutron guide hall in construction

NL 1NL 2NL 3NL 4NL 5NL 6 NL 2a-u NL 2a-o NL 2b NL 3b NL 3c NL 3a NL 4b NL 4a NL 5a NL 5b Neutron guides at SR-1 Schanzer, Borchert NL 5a NL 6b

 create guide end positions !!! Neutron guide system Instrumente: 1. MatSci-R5. Mephisto 9. SANS-113. Reflektometer17. PANDA 21. RESI 2. NSE6. KWS-310. PGA14. RSSM18. thermisches TOF 3. TOF TOF7. KWS-211. RESEDA15. DNS19. TAS-NSRE 4. REFSANS8. KWS-112. NOSPEC16. MIRA20. SPODI

Proofs ?

Anisotropic power density in FRM-II fuel element Comparison of power densities at different heights in the fuel element after two days at about 50 kWatt thermal power, recalculated and by measuring fission product activities some days after operation. Densities are measured and calculated at an outer segment (thickness 13 mm) as function of the azimuthal angle. A dip in the power density (arrow) is clearly visible near to the azimuthal position of the cold source (center at 98°). 1,8 1,7 1,6 1,5 1,4 1,3 1,2 1,1 1,0 0, azimuthal angle [degrees] power density [relative units] 20 cm below mid plane 20 cm above mid plane 140 La 487 keV activity 140 La 1595 keV activity 132 I 667 keV activity active core region collimatordetector Measurement setup

real rod position in very good agreement with 2d- calculation  element provides 52 days + maximal 10 extra days control rod position

Vertical beam divergence NL1 Karl Zeitelhack vertical inhomogenity of cold source

Twisted Neutron guide NL2b Karl Zeitelhack twisted guide element torsion: 2,5° / m twisted guide vacuum tube

Differential neutron flux at exit of NL2b Karl Zeitelhack  int. = 1,8x10 9 n/cm 2 /s extrapolated to 20MW reactor power  positions

Results Karl Zeitelhack Investigation of selected, characteristic neutron guides Measurement of integral and differential neutron flux NL1:  int. = 9,8  10 9 n/cm 2 /s (extrapolated to 20MW) ; NL2b:  int. = 1,8  10 9 n/cm 2 /s ´´ NL6a:  int. = 4,9  10 9 n/cm 2 /s ´´ Horizontal and vertical beam divergence, „effective“ reflectivity results consistent with coatings inhomogenity of cold source masks divergence distributions Simulation Calculations based on MCNP + McStas experimental results in good agreement with simulation  guides under study have good quality reliable predictions based on simulation calculation feasible twisted guide: phase space turn confirmed, but clearly needs further investigation

Innovative instrumentation !

First generation of instruments at FRM II Irradiation facilities Operator rapid pneumatic irradiation systemt trans ~ 250 ms TUM chemistry pneumatic rabbit systemt trans ~ s  TUM FRM-II hydraulic rabbit systemt trans > 10 s  TUM FRM-II irradiation position in control rod  fast  TUM FRM-II silicon doping facility  20 cm, length 50 cm  TUM FRM-II Clinical tumor therapy MeV neutrons TUM medicine Radio- and tomography with thermal neutrons  TUM physics with fast neutronsMeV neutrons  TUM chemistry prompt gamma analisys Uni Cologne Diffractometers material diffractometer  HMI Berlin powder diffractometer  TH Darmstadt/LMU Munich thermal single crystal diffractometer  Uni Augsburg/LMU Munich hot single crystal diffractometer  RWTH Aachen reflectometer for biology  GKSS Geesthacht/LMU Munich reflectometer for hard matter MPG Stuttgart

First generation of instrumentation at FRM II Spectrometer Operator resonance spin-echo spectrometer  TUM physics back scattering spectrometer FZ-Jülich cold time-of-flight spectrometer  TUM physics cold triple-axis-spectrometer  TU Dresden/TUM physics thermal triple-axis-spectrometer  Uni Göttingen/TUM physics polarised triple-axis-spectrometer  MPG Stuttgart Positron source  Uni German army Fundamental research beam for nuclear physics  TUM physics beam for optical experiments  TUM physics Under construction & future small angle camera SANS-1 TUM/Uni Göttingen/GKSS 7 instruments from FZ-JülichFZ-Jülich 3 small angle cameras diffuse scattering spin echo spectrometer high intensity reflectometer thermal inelastic TOF spectrometer bio diffractometer TUM physics Munich accelerator for fission products (MAFF) MLL Munich ultra cold neutrons MLL Munich

4 piston engine driven at 600 rpm time resolution 1 ms Schillinger, Brunner, Calzada, FRM-II

Neutrons have wavelength Bragg equation n = 2d sin  detector d   internal stress

Optimisation of a crankshaft Mayer, Achmus, Pyzalla, Reimers - HMI, BMW

neutrons in the heart of a university campus

View on top of the reactor vessel