How does the bounty system work?

So i know the basics that when you get up to 3 kills (without dying) you get a bounty and when you're killed you're shut down. But i want to know how much gold does each kill add to your bounty, adn if you get excuted does your killing spree end? Also, are there assist sprees? i know that if u keep dying you're worth less gold (id also like to know how much less) but if you assist in a kill after dying do you go back to the regular bounty? because if you dont that means that a support is worth almost no gold if they dont get kills even though they're assisting. I just want to know everything i guess lol Any information is appreciated