Progress of J-PARC/MLF

Arai, Masatoshi

Although we had a difficulty of disaster and accident, we have steadily operated the neutron source. Now the accelerator power is about 300 kW, and we will ramp up to 500 kW or more in the late fall this year. Now a He-gas injection into the Hg flaw of the target is implemented. We have found the injection of the Helium micro bubbles can have a drastic effect on the target pitting mitigation. We have also installed an octupole magnet in the proton beam transport line in order to reduce peak heat deposition density in the target by flattening the peak top of the proton beam profile. All of instruments have been well operated without any serious problem. However, we have found a weak point on shielding at 1 MW. During the last operation at 300 kW, we have confirmed the performance of instruments with a new concept. New data acquisition system with the event-recording method has showed effectiveness and flexibility in experiments and versatility in data analysis.