Target & Horns

• Fluxes were distributed. W/ J-PARC type　 2.5o, 2o, 3o.

• Target cooling

evaluation and test

• Target stress analysis

• Serious stress analysis started for 1st horn

consistent w/ simple calculation

• Optimization of the horns

• Load test was done w/ mini-1st horn.

Fluxes w/ J-PARC type　 2.5o, 2o, 3o.

Progress by S.Ueda and Target&Monitor group

• Required heat convection coefficient btw. water and graphite was evaluated . Tsurf < 100o

Both Tsurf and Twater were evaluated.

• Actual heat convection coefficient was measured.

Target cooling

surfwatersurf TSTTSQ )(Q 　　 : ~60kJ/3.3sec.

Twater

Tsurf

water

targetQ

Tsurf Max.

α=6

TsurfRequired Heat Convection coefficient

Q

Z=0cmZ=90cm

beam ターゲット水

Result

>6.5[kW/Km2]@15l/min

>5.8[kW/Km2]@20l/min

•Heat deposit onto the water is not yet taken account.

•These are based on simple calculations.

FEM analysis is being carried out.

S.Ueda

horn

target

90 cm

One of cooling schems

electrode

Cooling waterCooling Test

waterDC Current

Thermal stress estimation (ANSYS)Condition: Simulate the hottest part (z=100mm ~ 200mm) : The edges (z=100 & 200mm) are fixed in z direction.

just after the spill (after 5s)

100 200

Equivalent stress

(Because both of the edges were fixed)

z (mm)

maximum temperature

@ r=0, z=200mm ~14.5MPa.

@ maximum temperature~8.8MPa.

(r=0,z~170mm)

r (m

m)

0

15

slightly larger but consistent with the analytical calculations

(analytical calc.: 6.0MPa)

(due to the approximation of the temperature distribution)

Hayato, Minakawa

Further optimization –Horn1-Parameters default

Current I 320kA

Inner conductor radius rin 26 mm

Horn1 Length L1 1.5 m

Distance to Horn2 D2 0.5 m

Horn2 shape parameter a2 0.609

Horn3 shape parameter a3 0.0661

Fixed Parameters

Horn2 Length L2 2 m

Horn3 Length L3 2.5 m

Total Length 11.5 m

L1 D2 L2 D3 L3

Rin = 28 mm

L1 = 140cm

D2 = 50cm

Heat load by radiation to 1st horn

Ver4.8

Rin=23mm, Total : 70kJ/pulse

26mm, Total : 37kJ/pulse

28mm, Total : 35kJ/pulse

Time evolution of temperature at inner-condcutor

図 温度解析結果／内部導体最高温度部の温度履歴

0

10

20

30

40

50

60

70

80

90

0 5 10 15 20 25 30 35 40 45 50

s時間（ ）

℃温

度（

）

N2702

①

②

③

④ ⑤ ⑥ ⑦ ⑧ ⑨ ⑩ ⑪ ⑫ ⑬

rin=26mm, L1=150cm, wpulse=0.4ms

最高温度部

Asuming from K2K (Yamanoi et al.)

Stress analysis using ANSYS

beam

1st horn Cylindrical model

Only stress from Lorenz force is considered.

Stress from heat load should be considered.

3mm thick aluminum

eq < 20 MPa

Deformation < 60m

I=320kA

3mm thick aluminum

eq < 20 MPa

Deformation < 60m

Only stress from Lorenz forceeq < 23 MPa

Deformation < 100m

Previous version

Rin=26mm

Rin=28mm

Load Test

FSW

w/ Yamanoi