The diagram shows a two-chamber mass spectrometer device. Singly-charged ions (q
ID: 1310202 • Letter: T
Question
The diagram shows a two-chamber mass spectrometer device. Singly-charged ions (q = +|e|) enter from the left. They first pass through the velocity selector, a chamber of length L=1.81 meters where there is a magnetic field B = 0.19 Tesla pointing into the page and a vertical electric field E. The E field is created by a voltage V applied across the upper and lower plates shown (of separation d=0.57 meters). The E and B fields are chosen such that only particles of a certain velocity v pass undeflected through the tiny hole at the end of the chamber. The ions have net charge q = +|e| and mass m. If we want to select only those with velocity v=22 km/sec, what voltage V (in kilovolts) must we apply across the plates of the velocity selector?
Explanation / Answer
chamber of length L=1.81