I am looking for an alpha detector to do an alpha spectroscopy (and maybe beta as well). The rough setup is a vacuum tube with a detector in one end and a source in the other, possibly with a magnet in the middle. I have googled around, but my problem is that I don't really know what is good. I understand that a silicon detector has a very high energy resolution, which is what I want (although a radiation count will be a plus). So, what should I look for? What companies should I know of? Something in Europe would be awesome, so the delivery won't be too long.