ABSTRACT
Research investigating the application of pressure-cycled bubble chambers to fast neutron detection is described. Experiments with a Halon-filled chamber showed clear sensitivity to an AmBe neutron source and insensitivity to a (137)Cs gamma source. Bubble formation was documented using high-speed photography, and a ceramic piezo-electric transducer element registered the acoustic signature of bubble formation. In a second set of experiments, the bubble nucleation response of a Freon-134a chamber to an AmBe neutron source was documented with high-speed photography.
ABSTRACT
The development of capillary neutron optics permits a new technology for neutron capture therapy involving the application of a focused thermal neutron beam at the medically optimal location within the patient. A subthermal neutron beam begins to converge as it travels through a neutron "lens," reaching a narrow focus within a tube that allows it to pass directly to the treatment region. This technique results in a substantially lower dose to untreated parts of the patient and a substantially weaker radiation field in the treatment room generally. Additional advantages include the relative ease of thermal neutron generation and the ability to shield the patient completely and effectively from fast neutrons or gamma rays originating at the neutron source. This work describes the application of capillary optics to neutron capture therapy, along with Monte Carlo calculations of the neutron flux profiles within a patient for an optimized system design. Specific dose profiles for the case of boron neutron capture therapy within the brain are also provided.
