Target R&D for the J-PARC neutrino experiment (II)Two types of the stress analysis (LS-DYNA) time...

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Target R&D for the J-PARC neutrino experiment (II) Yoshinari Hayato (KEK/IPNS) for the J-PARC target R&D group

Transcript of Target R&D for the J-PARC neutrino experiment (II)Two types of the stress analysis (LS-DYNA) time...

  • Target R&D for the J-PARC neutrino

    experiment (II)

    Yoshinari Hayato (KEK/IPNS)for the J-PARC target R&D group

  • Temperature rise estimation (simulation input parameters)Target size 30mm φ x 900mm L

    Energy deposit 58kJ/spill

    Maximum energy deposit 185.9J/g

    Distribution of the energy deposit

    z

    r

    6.5kW/m2/KHeat transfer rate @ surface25oCTemperature @ surface (environment)

  • Temperature rise estimation (simulation input parameters)

    Material IG-43 (Toyo Tanso)density 1850kg/m3

    Temperature dependent material parametersThermal conductivitySpecific Heat

    0 200 400 600 800 1000 1200 0 200 400 600 800 1000 1200

    500

    1000

    1500

    2000

    (J/kg/K) (W/m/K)

    20

    60

    100

    Temperature (oC) Temperature (oC)

  • Temperature rise estimation (simulation input parameters )Time structure : for the detailed study, two patterns were simulated.

    30.78 34.20.42

    Hea

    t Loa

    d 1 2 3 4 10 11 12

    0 3 6.84 10.26Time (sec)

    37.62

    averaged 8spills/bunch

    5µs

    598ns

    58ns

  • Temperature rise estimationresults : (I) distribution in the target

    relative temp. from 25oCjust before the 11th spill

    r

    just after the 11th spill

    z Maximum Temperature : 45oC

    Maximum Temperature : 236oC

    r

    z

  • 図 グラファイトターゲットの温度変化

    0

    50

    100

    150

    200

    250

    300

    0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0 45.0

    経過時間(sec)

    温度

    (℃

    中心軸最高温度部

    外表面最高温度部

    C1C2 C3 C4 C5 C6 C7 C8 C9 C10 C11 C12

    50

    100

    150

    200

    250

    (oC)

    Maximum temperature at the center

    Maximum temperature on the surface

    図 グラファイトターゲットの温度変化(C12初期)

    0

    50

    100

    150

    200

    250

    300

    37.619999 37.620000 37.620001 37.620002 37.620003 37.620004 37.620005 37.620006

    経過時間(sec)

    温度

    (℃

    中心軸最高温度部

    外表面最高温度部

    50

    100

    150

    200

    250

    (oC)

    37.62000 37.62002 37.62004 (sec.)

    0 5 10 15 25 3020 35 40 (sec.)

    Temperature rise gradually decreasedbecause of the temp. dependence of Cp.

    Temperature is saturatedin a few spills.

    236oC @maximum

    85oC @maximum(Initial temp. : 25 oC)

    Temperature rise estimationresults : (II) time dependence

  • Thermal stress & displacements estimation ( simulation input parameters )

    20.0

    Linear ExpansionCoeff. (x10-6)

    Young’smodulusTemperature

    Temperature

    0.0

    50.0

    100.0

    150.0

    200.0

    250.0

    0 1 2 3 4 5 6 7 8 9 10 11 12

    時間(sec)

    温度

    (℃)

    Cycle 11 Cycle 12

    Cycle 11 and 12 of the previous analysis

    50

    100150200(oC)

    0 1 32 54 6 7 98 1110Time (sec)

    Material properties

    (oC) (MPa)0.0 10760 3.6814

    10790 3.762063100.0 10920 4.065344200.0 11080 4.48612400.0 11410 4.926584

    Two types of the stress analysis (LS-DYNA)

    time step : 1µs (from 0 to 205µs)For the radial displacements (fast components)

    For the longitudinal displacements (slower components)time step : 10µs (from 0 to 2050µs)

  • Thermal stress & displacements estimationresults : (I) equivalent stress

    Just after the 11th spill

    Maximum equivalent stress

    (x10 MPa)

    6.8MPa

  • Thermal stress & displacementsresults : (II) displacements (radial direction)

    5.000055.0 5.00010 5.00015 5.00020

    1.0

    2.03.04.0

    5.06.0

    x10-3(mm)

    (sec.)

    Displacement in the radial direction~ 6x10-3mmMaximum displacement

    Vibration cycle ~ 6µs

  • Thermal stress & displacementsresults : (III) displacement (longitudinal direction)

    5.00055.0 5.0010 5.0015 5.0020

    -2.00

    -1.00

    x10-1(mm)

    (sec.)

    Displacement in the longitudinal direction~ 2.5x10-1mmMaximum displacement

    Vibration cycle ~ 250µs

  • Maximum temperature @ center

    Maximum temperature @ surface

    FEM simulation results~ 236oC

    ~ 85 oC(analytical : @ center ~ 250oC )

    Summary & future prospects (I)

    Maximum stress ~ 6.8MPa(analytical ~ 7.5MPa)

    Consistent with the analytical calculation.

    ~ 6x10-3mmradialMaximum displacement~ 2.5x10-1mmlongitudinal

    ~ 6µsradialVibration cycle~ 250µslongitudinal

  • Summary & future prospects (II)Remaining questions / problems

    1 piece or split the target into smaller pieces?Off centered tolerance has to be estimated.

    (Non-uniform heating may cause the problem.)

    Can we put the graphite target in the water?Is it necessary to put the target in the container

    (to avoid graphite to touch the cooling water)?If we split the target into smaller pieces,

    we have to put the target in the container.

    water flow

    Graphite target

    (To avoid the water to get in the middle of the beam.)container(?)

    Schematic view of the possible target (cooling) system

  • Summary & future prospects (II)Irradiation effects

    Target may shrink by ~1(a few?)%Large target (L=900mm) may not be possible.

    If we put the target in the container, they will be separated.

    How to hold the target (in the container)?

    Plan to measure the irradiation effects on the material properties

    Very rough scheduleFY 2003 simulation studies & basic cooling tests.

    design the prototype (target holder, cooling system).FY 2004 make the prototype and test.

    design the target support & handling system.measure the irradiation effects.

    FY 2005 mockup tests (including supports & handling system).material determination.

  • 変形倍率200倍にて表示赤ライン=変形前変形値単位=mm

    A部拡大図 B部拡大図

    グラファイトターゲット熱応力衝撃解析:変形図            (⑦ 軸変形最大=5.000125sec)拡大図

    Target R&D for the J-PARC neutrino experiment (II)