What are good defensive weapons in elite dangerous?

I am getting annoyed with the fact that I have to rely on my speed and FSD to get out of being attacked while mining/after being interdicted, and would like to know what the best defensive weapon is. What I am looking for is something that will get me out of a sticky situation relatively easily, but for a not-too-expensive price, as I am an amateur miner, and tend to earn money from completing transport missions, so money isn't the best for me. My ship is the viper MKIV, and my current weapons are 2 pulse lasers (gimballed) and a point defence. What I would really like is just something that could fire and/or aim automatically, and cause a decent amount of damage. Thanks in advance for any help.