Speaker
Prof.
Xufei Wang
(Fudan University, China)
Description
Biological proton microbeam for sub-cellular irradiation is constructed in Fudan University, on a 2×3MV tandem accelerator (NEC-9SDH2). With a 14 meters beam line (8.6m horizontal and 4.5m vertical), energetic protons is chosen by a 30°magnet analyzer and bended vertically up by a 90°bending magnet, and finally focused and pre-collimated to the beam exit at the endstation. To produce an external proton beam down to a sub-cellular size, a capillary collimator of 1.5μm ID and 1mm length is used, though which a collimated proton beam of 3MeV (FWHM<40keV) can be acquired with a spatial resolution <2.2μm in air. The precise detection of the protons are performed by a scintillation detector using a 13μm scintillator film (BC400) at the beam exit together with a photomultiplier (Hamamatsu R7400U) mounted above the target living cells cultured on a 3μm Mylar dish. The counting signals from the photomultiplier is discriminated by NIM electronics and counted by a computer-based counter, which sending the feedback signal to a fast beam deflector on the horizontal beam line for a fast beam cutting in 1μs, when preset number of protons is delivered to target cells. Imaging system are also set up with a cooled CCD camera mounted to Olympus microscope (BHT), and the image processing and cell irradiation steps are automatically performed by a central computer with home-developed program.
The current performance of the Fudan microbeam is summarized as: external proton beam (3MeV, FWHM<40keV) produced by capillary collimator, with a beam size of 2.2μm in air; CR39 tracking method has demonstrated a single-hitting precision >95% and a targeting discrepancy within ±2μm.
Primary author
Prof.
Xufei Wang
(Fudan University, China)
Co-authors
Prof.
Chunlin Shao
(Fudan University, China)
Mr
Jianzhong Wang
(Fudan University, China)
Mr
Jiaqing Li
(Fudan University, China)
Mr
Jiexiong Zhang
(Fudan University, China)
Prof.
Liqun Shi
(Fudan University, China)
Dr
Wei Zhang
(Fudan University, China)
