You can definitely get a job as a staff researcher at a national lab or small applied-science company (there are a ton of companies doing DARPA research). Note that due to the way the world is, you may not be able to be the prime scientist on a contract, but that does not stop you from doing basic research via collaboration.
If your contributions become noteworthy in the field, then along with the relationships that you've generated with your DARPA/NSF/? partner, you will eventually be able to be a prime.
To reiterate some of the other comments here, you may not be able to pick the 'basic research' that you want to work on in the above scenarios... usually the grant sponsors decide that.
Thank you for the reply. Do you mind if I ask some more questions? Suppose that I am financially independent and do not care about being paid, then would that open up more paths for me?
If your contributions become noteworthy in the field, then along with the relationships that you've generated with your DARPA/NSF/? partner, you will eventually be able to be a prime.
To reiterate some of the other comments here, you may not be able to pick the 'basic research' that you want to work on in the above scenarios... usually the grant sponsors decide that.