1. Beam dump for J-Parc neutrino facility

2. Requirement For the 1st phase: accept 0.75 MW beam
For the 2nd phase : accept 4MW beam
Heat Load
Among total beam power, 20% is deposited at dump.
Radiation shielding
11mSv/h at the boundary of concrete and soil
0.25mSv/h at the surface of soil
Muon Monitor
monitor the direction and intensity of the beam

3. Thickness required for radiation shielding
Top View
The amount and shape
of iron should be optimized.
Front View
Side View

4. Heat load from radiation
At x=0 plane
unit: J/cm3/pulse

5. Example of Heat Analysis(4MW)
½ Model
Boundary condition
(All) outer surface of the iron is cooled by water.
concrete
Temperature distribution in Iron
beam
iron
soil
Result
Max. in iron : 700oC
-> need aluminum plate or something
in concrete : 54oC

6. Muon monitor Monitoring of the beam direction and intensity.
Threshold 8 GeV/c ? Probably 5 GeV/c is preferable…
(under study)
To achieve 5 GeV/c threshold, the monitor has to be installed between irons under high radiation condition.