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A free neutron is said to have a half life of something around 15 minutes, or maybe it's 18 minutes, I can't remember exactly. This brings up a couple of questions.
(1) How does the experimenter maintain a neutron in a free state? Presumably maintaining a high vacuum is one requirement, but given a vacuum chamber, how does one keep a neutron from touching a wall of the chamber? Is the nonzero magnetic moment of the neutron somehow utilized?
(2) Why is beta decay typically suppressed when the neutron is inside of a nucleus? Once the neutron is part of a nucleus, depending on the particular isotope, it may last billions of years. What is going on? I know that once in a nucleus, the neutrons and protons interconvert due to exchange of charged pions. But one might naively assume that the nucleons would then beta decay in about twice the half life of a free neutron, because of the thought that any given nucleon is spending half of its time as a stable proton. (Actually, I think protons can also decay in certain highly-energetic nuclear states, but that's a topic for another discussion.)
(1) How does the experimenter maintain a neutron in a free state? Presumably maintaining a high vacuum is one requirement, but given a vacuum chamber, how does one keep a neutron from touching a wall of the chamber? Is the nonzero magnetic moment of the neutron somehow utilized?
(2) Why is beta decay typically suppressed when the neutron is inside of a nucleus? Once the neutron is part of a nucleus, depending on the particular isotope, it may last billions of years. What is going on? I know that once in a nucleus, the neutrons and protons interconvert due to exchange of charged pions. But one might naively assume that the nucleons would then beta decay in about twice the half life of a free neutron, because of the thought that any given nucleon is spending half of its time as a stable proton. (Actually, I think protons can also decay in certain highly-energetic nuclear states, but that's a topic for another discussion.)