The laser energy used to move the muon up to that unstable state can be used to calculate the radius of the helium nucleus, which is 1.67824 femtometers—one femtometer being one quadrillionth of a meter.
用于将μ
提升到不稳定状态的激光能量可以用来计算氦核的半径,其大小为1.67824飞米——一飞米等于一千万亿分之一米。