The document describes Aston's Mass Spectrograph, which uses electric and magnetic fields to separate ions based on their mass-to-charge ratio. Positive ions are passed through narrow slits and enter perpendicular electric and magnetic fields, causing the beam to disperse based on differences in velocity from their mass-to-charge ratios. The magnetic field then reconverges the dispersed beam onto a photographic plate, allowing the different ion masses to be identified. The mass spectrograph provides advantages like mass identification but has limitations such as a non-linear mass scale.

1. Aston’s Mass Spectrograph

2. Contents:
1.
Introduction
2. Principle
3. Working
4. Derivation
5. Advantages
6. limitations
7. References

3. Introduction:

4. Principle :

5. Working :
The stream of positive ions is rendered into a fine beam by passing it
between two narrow slits S1 and S2.
This beam enters the electric field of strength (E) between metal plates
P1 and P2. Due to action of the electric field all positive ions having the
same value of specific charge (q+/M) are not only deflected by an angle
𝜃 but are also dispersed by an angle d 𝜃 due to their different velocities.

7. Continue…..
The beam is then allowed to pass through slit S3 and enter a magnetic
field of strength B arranged perpendicular to the electric field so as to
deflect the beam in the opposite direction and converge it to a single
point F on a photographic plate. The magnetic field deviates the beam
through an angle ∅ and reconverges them by an angle d∅.

8. Working :

9. Derivation:

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15. Advantages:

16. Limitations :
• The mass scale is not linear.

17. References :
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