Here are the 2 texture files and how I changed them...
cutting_beam
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cutting_beam2
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Here are a couple of ingame screenshots of them in action...
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cuppled with the right sound file, it works great.
but you can see how there are multiple instances of the beam in each texture file... 6 of them... so all you need to do is to narrow each instance... you just need to play with the files abit until you like what you see.