Chlorine has two stable isotopes, 35Cl and 37Cl. Chlorine gas which consists of singly ionized ions is to be separated into its isotopic components using a mass spectrometer. The magnetic field strength in the spectrometer is 1.2 T. What is the minimum value of the potential difference through which these ions must be acceler- ated so that the separation between them, after they complete their semicircular path, is 1.4 cm?

Respuesta :

Answer: The minimum value of the potential difference through which these ions must be accelerated is [tex]1.87 \times 10^{-5}[/tex] MV.

Explanation:

The given data is as follows.

    [tex]m_{1}[/tex] = 35 amu

              = [tex]35 \times 1.66 \times 10^{-27}[/tex]

              =  kg

     = 37 amu

          = [tex]37 \times 1.66 \times 10^{-27}[/tex]

          =  kg

It is known that,

    work done on charged particle = gain in kinetic energy

So,      

               v = [tex]\sqrt{(2 \times q \times \Delta_{V/m})}[/tex]

A centripetal force is experienced when charged particles enter a uniform magnetic field.  

Hence,     F = [tex]q \times v \times B (sin(90))[/tex]

        [tex]\frac{m \times \frac{v^{2}}{r} = q \times v \times B[/tex]

                    r = [tex]\frac{m \times v}{B \times q}[/tex]

And,      

             [tex]r_{2} = \frac{m_{2} \times v_{2}}{(B \times q)}[/tex]

On completion of semi circle, the distance between two paths =

   [tex]0.7 \times 10^{-2} = (\sqrt(2 \times m_{2} \times delta_{V/q}) -\sqrt{(2 \times m_{1} \times \frac{\Delta_{V/q}}{B}}[/tex]

 [tex]0.7 \times 10^{-2} = \sqrt{(\Delta_{V})} \times (\sqrt(2 \times \frac{m_{2}}{q}) - \sqrt{\frac{(2 \times \frac{m_{1}}{q}))}{B}}[/tex]

[tex]\sqrt{(\Delta_V)} = 0.7 \times 10^{-2} \times \frac{B}{(\sqrt{(2 \times \frac{m_{2}{q})} - \sqrt{(\frac{2 \times m_{1}}{q}))}[/tex]

= [tex]\frac{0.7 \times 10^{-2}  \times 1.2}{(\sqrt{(2 \times \frac{6.142 \times 10^{-26}}{(1.6 \times 10^{-19}})}) - \sqrt{(2 \times \frac{5.81 \times 10^{-26}}{(1.6 \times 10^{-19}))}[/tex]

               = 350 volts

    [tex]\Delta_V[/tex] = [tex]\sqrt{350}[/tex]

                   = 18.7 volts  

                  = [tex]1.87 \times 10^{-5}[/tex] MV

Thus, we can conclude that the minimum value of the potential difference through which these ions must be accelerated is [tex]1.87 \times 10^{-5}[/tex] MV.