first welcom to goy' now type bind weed in the serch box top right of this page ,that will help you.

you will probably need to use one of those touch stick's, they have strong weedkiller in them and you only kill what you touch then.

welcome to GoY.
I use systemic weedkiller in late summer. the rest of the time I pull it as soon as I see it. If I am feeling generous I will excavate it as if it was an archeaological site and great satisfaction of getting 3ft or more lengths.

You could try putting canes in the ground at intervals through your raspberry bed and when the bind-weed grows up the canes treat them individually with an appropriate weed killer...:>)

To be realistic you probably will never completely rid yourself of it in this situation. I once knew a 90 year old woman who completely removed bindweed from her rockery, but did so by putting glyphosate in jam jars, and trailing the stems into this. After 24 hours, she moved the jar to the next bit and so on.
Few of us have the patience to do this (or the time) but it DID work and she removed all the bindweed.
I hate to use weedkiller, but when it comes to bindweed, only regular treatment as suggested above will work.
If you REALLY want to get rid of it completely, you need to dig up all the canes, double dig the area carefully removing every bindweed stem, and then (if it's coming in from a neighbouring hedge or garden) put some kind of barrier into the soil to stop future spread.
Personally, I'd enjoy the raspberries, and frequently crawl around the canes with some secateurs to snip the stems of the bindweed off. At least that controls it.