Scientific Program at RIKEN-RAL Port 1

At Port 1, muon catalyzed fusion experiments are being started. (Good review to a beginner was given in New Scientist 16 August 1997. Vol. 155 No. 2095 ) (Easy introduction to muCF in Japanese exists here. Negative muon beams are stopped in the liquid target of mixed Deuterium and Tritium (isotopes of hydrogen). By the electric repulsive force, these atoms cannot come near enough to fuse. However, the negative muon neutralizes the positive electric charge and makes a very small muDT molecule where D and T atoms can be near enough to make fusion. This process occurs quickly and the released muon can make another D-T fusion. So this process is called muon CATALYZED fusion.

The negative muon can escape from this cycle by either decaying to electron, being captured by He3 nuclei which is daughter of tritium nuclei, or being captured by He4 nuclei which is fusion product of d-t nuclear fusion (muon-alpha sticking) . Our tritium gas handling system has a helium removal system so that we can make He3 free D-T target.

In order to study the muon-alpha sticking process, we installed a Si(Li) detector to measure X-ray emitted when a negative muon is captured by He4 nuclei, and a neutron detector to observe neutron from fusion reaction.

The advantage of pulsed muon beam can be clearly seen in a spectrum of X-ray which shows a peak from muon-alpha sticking. This measurement was possible because we can deduce background X-ray from tritium decay by using muon beam timing.

publication list

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