1 1 מ חויבות ל מ צוינות - ג רעין להצלחה 200 kW Liquid Lithium Neutron Source G. Shimel, A. Arenshtam, I. Eliyahu, A. Kreisel, I. Silverman 6 th High Power Targetry Workshop 11-15/4/2015, Oxford, England

2 2 מ חויבות ל מ צוינות - ג רעין להצלחה Talk Layout  Soreq Applied research Accelerator Facility (SARAF)  Conceptual design of the Thermal Neutron Source (TNS) & convertor options  SARAF experience with a liquid lithium neutron source  A very preliminary design of a 200 kW liquid lithium neutron source

3 3 מ חויבות ל מ צוינות - ג רעין להצלחה Background  Soreq nuclear reactor (IRR-1) is in operation since 1961  It provides:  Neutron radiography  Neutron diffraction  Samples irradiation  Soreq infrastructure should be modernized to support experimental nuclear physics research in Israel Jerusalem Tel-Aviv

4 4 מ חויבות ל מ צוינות - ג רעין להצלחה SARAF Layout RF Superconducting Linear AcceleratorTarget Hall A. Nagler et al., LINAC 2006 and LINAC 2008 N. Pichoff, EPAC2015 Phase I Phase II

5 5 מ חויבות ל מ צוינות - ג רעין להצלחה Accelerator Basic Characteristics A RF Superconducting Linear Accelerator CommentValueParameter M/q ≤ 2Protons/DeuteronsIon Species 5 – 40 MeVEnergy Range Phase I - 2 mA0.04 – 5 mACurrent Range PW: ms; rep. rate: Hz CW and PulsedOperation mode 6000 hours/yearOperation 90%Reliability beam loss < 1 nA/mHands-OnMaintenance

6 6 מ חויבות ל מ צוינות - ג רעין להצלחה SARAF Phase-I Accelerator L. Weissman, Linac 2010 D. Berkovits, Linac 2012 A. Kreisel, Linac 2014 L. Weissman, WAO 2014 MeVmA p41 CW p22 CW d5.61*10%

7 7 מ חויבות ל מ צוינות - ג רעין להצלחה Conceptual system design קו קרן Raster דיפרקטומטר מקור ניטרונים TNR Diffractometer Thermal neutron source 7 Li(d,xn) beam 6 m beam raster concrete shield diffractometer collimator L/D=250 image plane 2 m heavy concrete shield collimator

8 8 מ חויבות ל מ צוינות - ג רעין להצלחה Available technologies for neutron converter design LithiumBerylliumCarbonTarget design Birmingham BNCT, BINP LENS, SPESSPIRAL-IStatic ?ESS-BILBAOFRIB, SPIRAL-IIRotating IFMIF, LiLiTXXLiquid DrawbacksAdvantagesTarget design High heat flux, Radiation damage, Large neutron source SimpleStatic Complex mechanism, Reduced neutron conversion efficiency Low thermal stress, Low radiation damage density Rotating Complex system, Only for lithium Low thermal stress, Low radiation damage Small neutron source Liquid

9 9 מ חויבות ל מ צוינות - ג רעין להצלחה A liquid lithium jet target - LiLiT tested at SARAF beam corridor Scrubber port Containment Graphite fire extinguisher Beam diagnostic Beam Measured: Li jet velocity 7 m/s Maximum power density 1 MW/cm 4 m/s 2x MeV protons M. Paul (HUJI) S. Halfon et al.: ARI 69(2011)1654 AIP 1525 (2013)511 RSI 84(2013) RSI 85(2014) ARI 88(2014)238 M. Paul et al.: POS (2014) 059 J.RNC (2015)

10 מ חויבות ל מ צוינות - ג רעין להצלחה Liquid Lithium Target - LiLiT  Proton energy: ~2 MeV  Proton current: <3.5 mA  T ≈ C  T max ≈ C  Operating at SARAF since 10/2013 Jet: 18 mm x 1.5 mm Lithium velocity: 20 m/s Wall assisted lithium jet Jet chamber liquid lithium beam S. Halfon et al., Review of Scientific Instruments 84, (2013).

11 מ חויבות ל מ צוינות - ג רעין להצלחה LiLiT installation at SARAF Beam S. Halfon et al., Review of Scientific Instruments 85, (2014).

12 מ חויבות ל מ צוינות - ג רעין להצלחה LiLiT thermal model Temperature distribution at the center of the jet Flow direction Beam

13 מ חויבות ל מ צוינות - ג רעין להצלחה Liquid lithium free surface proton irradiation P beam, 1.81 MeV, ~1 mA Lithium flow Proton beam Emissivity -  Li =  SS = Side plates with thermocouples

14 מ חויבות ל מ צוינות - ג רעין להצלחה Measured lithium temperature Beam position on target Thermal track 1.5 mA Protons beam at 1.92 MeV Beam power ~3 kW Beam size, σ=2.5 mm Calculated heat-up 200 o C Measured ~ 50 o C(±50)

15 מ חויבות ל מ צוינות - ג רעין להצלחה Available technologies for neutron converter design LithiumBerylliumCarbonTarget design Birmingham BNCT, BINP LENS, SPESSPIRAL-IStatic ?ESS-BILBAOFRIB, SPIRAL-IIRotating IFMIF, LiLiTXXLiquid DrawbacksAdvantagesTarget design High heat flux, Radiation damage, Large neutron source SimpleStatic Complex mechanism, Reduced neutron conversion efficiency Low thermal stress, Low radiation damage density Rotating Complex system, Only for lithium Low thermal stress, Low radiation damage Small neutron source Liquid

16 מ חויבות ל מ צוינות - ג רעין להצלחה Neutron Convertor Specifications UnitValueParameter -DParticle MeV40Energy mA5Current kW200Power mm19Range

17 מ חויבות ל מ צוינות - ג רעין להצלחה Estimated operating limitation Flow Beam Evaporation rate [gr/cm 2 *hr] Simulation parameters: Q 200 kW U 5 m/s  4 mm Simulation parameters: Q 200 kW U 5 m/s  4 mm

18 מ חויבות ל מ צוינות - ג רעין להצלחה Estimated operating envelope * Y. Momozaki, HPTW3, 2007

19 מ חויבות ל מ צוינות - ג רעין להצלחה Required target parameters UnitValueParameter mm22-25Thickness mm50Width mm8 Max. beam size  mm4 Min. beam size  m/s5Velocity l/min375Flow rate l200Li inventory

20 מ חויבות ל מ צוינות - ג רעין להצלחה Target system layout Machines room Target & moderator Exp. hall Beam line Exp. hall EMP Li tank & Heat exchanger Beam line Moderator Target Beam line Target Diffractometer Radiography Samples irradiation

21 מ חויבות ל מ צוינות - ג רעין להצלחה Summary  SARAF phase-II facility will include a n/s thermal neutron source  The design is based on a 200 kW liquid lithium target for 40 MeV deuterons beam  Design choices for target has been reviewed based on:  Short and long term failure modes  System requirements  R&D risk analysis

22 מ חויבות ל מ צוינות - ג רעין להצלחה End

23 מ חויבות ל מ צוינות - ג רעין להצלחה Target fail modes review – R&D risks  Short term fail modes  Target cooling  Mechanical loads  Medium\ Long term fail modes  Radiation damage – limited knowledge, difficult to evaluate  Mechanical reliability  Radiation safety

24 מ חויבות ל מ צוינות - ג רעין להצלחה Micro-channels cooling of a solid target Proposed 80 kW micro-channels cooled neutron source (size 100x100 mm 2 ) and prototype test section (channel width 0.2 mm, made of Aluminum) H. Hirshfeld et al., NIM A 562(2006)

25 מ חויבות ל מ צוינות - ג רעין להצלחה Micro-channels cooling – experimental results Measured wall temperature above coolant temperature as function of heating power flux for two flow rate. Distinctive change in heat transfer capability can be noticed at power flux of about 600 W/cm 2. Stable operation has been achieved for heating power of up to 1400 W/cm 2 Start of boiling

26 מ חויבות ל מ צוינות - ג רעין להצלחה Radiation damage from high current low energy proton beam  Irradiation of solid targets cause fast accumulation of hydrogen gas at traps close to the targets surface (depth < 100 μm)  Unless released or chemically locked, the gas bubbles may fracture the target SARAF phase-I Tungsten beam dump after irradiation by X mA*hr protons at Y MeV

27 מ חויבות ל מ צוינות - ג רעין להצלחה Radiation damage in Be thick targets Design studies for ESS-BILBAO neutronic applications laboratory ESS-BILBAO Target Group ESS-B rotESS-BLENS Avg. Intensity [mA] Operation time [hr] 4.518Implantation [a/cm 3 ] Life time estimation regarding gas implantation 50 MeV p beam