Physics:Time of flight detector

A time of flight (TOF) detector is a particle detector which can discriminate between a lighter and a heavier elementary particle of same momentum using their time of flight between two scintillators. The first of the scintillators activates a clock upon being hit while the other stops the clock upon being hit. If the two masses are denoted by [math]\displaystyle{ m_1 }[/math]and [math]\displaystyle{ m_2 }[/math] and have velocities [math]\displaystyle{ v_1 }[/math] and [math]\displaystyle{ v_2 }[/math] then the time of flight difference is given by

[math]\displaystyle{ \Delta t = L\left(\frac{1}{v_1}-\frac{1}{v_2}\right)\approx \frac{Lc}{2p^2}(m_1^2-m_2^2) }[/math]

where [math]\displaystyle{ L }[/math] is the distance between the scintillators. The approximation is in the relativistic limit at momentum [math]\displaystyle{ p }[/math] and [math]\displaystyle{ c }[/math] denotes the speed of light in vacuum.

See also

• Time-of-flight
• Time-of-flight mass spectrometry