Hi all, I'm a junior physics/applied math double major at a state school in Wisconsin. I'm on my third year of nuclear physics research experience (freshman year wasn't physics, but it was nuclear related) and I'm looking to go to grad school for a PhD likely in physics, applied physics or nuclear engineering. I'm leaning primarily towards applied physics at this point. My question is this, how do different research opportunities match up? That is, an REU at another school, research at a national lab, working with a prof at your school etc. My research advisor has told me that she can send me to a national lab over the summer if I have no other desires, where I would likely work on another nuclear physics project. However, I am beginning to get a little concerned as I have never experienced another field other than nuclear physics. Not that I dislike the field, I do enjoy it a lot, but I don't want to end up wishing I would've tried something else in the future. That being said, I may have the opportunity to study computational fluid dynamics with a professor from my current university. How different would these summers potentially be viewed by a graduate school? I'm trying to build the best application I can (my understanding is applied physics programs are quite competitive). Of course my own interests should play a role as well, I have heard fluids is a good place to start for plasma, which is also a field of interest for an applied physics PhD. He got his degree from Cornell and has done a good amount of fluid dynamics research in the past but not quite as much nowadays, though of course he still does to some extent. My other question is, how is taking 5 years to earn a degree viewed by a graduate institution? I wouldn't be really reducing my course load but it would allow for more classes as well as another year of research experience. I have had some personal (family) issues in the past and struggled a little in school my first two years (sitting on a ~3.2). I'm in a significantly better state after my first REU this summer and am confident my grades will be up but I would think a 5th year would aid my application. Any responses are much appreciated!