In September, the state plans to open a portion of new prison where inmates will spend 23 hours a day alone in their cells. For the remaining hour, prisoners will move to a slightly larger cell to exercise by themselves. Colorado State Penitentiary 2--or CSP 2-- is in Canon City and is designed for inmates who, corrections officials say, are too dangerous or disruptive to be with other prisoners.   But research suggests that long stretches in solitary confinement can lead to mental health problems and make inmates ill-equipped to deal with life on the outside.  The average stay for someone in isolation in Colorado is about two and a half years. We hear first from Craig Haney, who's done a lot of research in this area. He's a professor of Psychology at the University of California, Santa Cruz.  Then Ryan Warner speaks with Ari Zavaras, head of the Colorado Department of Corrections. He says the state needs a new prison--and more isolation cells--for  inmates who are too dangerous to live with the general prison population. (Photo: National Geographic)