Diffraction effects in slit experiments

[sgn]

In double slit experiment with a single source,I am finding the traces of one slit when I have the other one open. I think this is due to diffraction effects.May I know how to tackle this?

 

[blue_leaf77]

I am finding the traces of one slit when I have the other one open

Do you mean the diffraction pattern of the double slit exhibits some kind of modulation where the overall diffracted intensity become less and less as you go further from the center? If that's what you mean, you are right that's an effect inherent in a diffraction pattern. Which means you can't completely remove this effect from your experiment, you can only suppress it. As you have said such modulation is reminiscent of the single slit diffraction pattern. So you can think of something of how to make this modulation less apparent by thinking the experiment in term of single slit.