Energy Conversion between Cycles of HIRFL-CSRm
The energy conversion of HIRFL-CSR(Heavy Ion Research Facility in Lanzhou- Cooling Storage Ring) is realized on October 15, 2008 after 10 days’ commissioning. The energy of slow extracted beam can be switched among several levels automatically between cycles. This marks another sticking point towards therapy research of deep sites tumors after the successful slow extraction realized in January 2008. The DCCT current signals of successive cycles of C4+ beam with energies 150MeV/u and 300MeV/u are shown in Fig. 1. On the right of Fig.1 the plastic scintillator signals of extracted beam with different energies are presented.
Fig.1 The DCCT current signal(left) and the plastic scintillator signals of successive cycles of C4+ beam with energies 150MeV/u and 300MeV/u
The energy conversion technology of slow extracted beam is one of the most pivotal technologies. The researchers of Institute of Modern Physics, CAS has tested and treated 82 samples(total 7 groups) of the shallow sited tumor therapy with good treatment effect, by using the 100MeV/u carbon beam provided by cyclotrons. The treated case is limited by energy from HIRFL, only tumors sited not more than 2.1cm in depth can be treated. The realization of energy conversion slow extraction makes it possible to treat patients using carbon beam of energy 80MeV/u to 400MeV/u, regardless the position of the tumors. The realization of therapy research of deep sites tumors makes China one of the countries hold the technology after Germany, Japan and the U.S.