The double-slit experiment's effectiveness depends on the relationship between the slits' separation and the incident beam's characteristics. For optimal interference patterns, the beam must straddle both slits, the slits must be narrow enough for significant single-slit diffraction, and they must be close enough to ensure overlapping diffraction patterns. While slits can be separated widely, maintaining the beam's coverage on both slits is crucial, and increasing distance reduces intensity, affecting pattern visibility.
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It depends on the spread of the incident beam, which needs to cover both slits. If you put the slits too far apart, then all of the incident beam is absorbed by the first barrier.brajesh said:Summary:: I was wondering how far apart the slits can be and the double slit experiment still works?
How far apart can the slits be and the double slit experiment still works i.e the wave interference pattern is seen on the target screen?
The double-slit is not anything special: it's just the way nature works. It's not a trick. Whatever set up you have, you can do the calculations and predict the result.brajesh said:So does that mean that theoretically, let's say the incident beam spread is an arc of 30 degrees, then if I move the slits apart AND also keep moving the barrier further away such that both slits are still covered by the beam, that I could have a very large separation and still continue to see the effect?
Yes, although as we move the barrier away the intensity goes down so there's less of anything to see - or equivalently the dots per second rate goes down and it takes longer for the pattern to build up.brajesh said:So does that mean that theoretically, let's say the incident beam spread is an arc of 30 degrees, then if I move the slits apart AND also keep moving the barrier further away such that both slits are still covered by the beam, that I could have a very large separation and still continue to see the effect?
What would you be trying to accomplish by having the source 30 degrees (or whatever angle) off the vertical? Normally you want the source to go straight to the slits so that they are illuminated as close to equally as possible. To the extent they are not equal, the interference effect is lessened.brajesh said:So does that mean that theoretically, let's say the incident beam spread is an arc of 30 degrees, then if I move the slits apart AND also keep moving the barrier further away such that both slits are still covered by the beam, that I could have a very large separation and still continue to see the effect?
Let me try to be semantically pedantic. I would prefer to talk about the "width" of the essentially collimated incident beam. "Spread" implies to me a large lack of incident collimation and simply complicates the picture.PeroK said:It depends on the spread of the incident beam
I was using "spread" as a synonym for statistical dispersion:hutchphd said:Let me try to be semantically pedantic. I would prefer to talk about the "width" of the essentially collimated incident beam. "Spread" implies to me a large lack of incident collimation and simply complicates the picture.