hi friend .,
actually the source for terahertz is that when an high speed electron is being deflected from its straight line path .. the energy loss during its deflection or turning is released in form of terahertz radiation ..
terahertz radiation is capable of replacing x-rays but it will not cause any harmfull effects as x-rays .
Terahertz is the bleeding edge of technology and therefore extremely expensive. If you want to do serious work in this region look to doing a PHD and get someone else to pay for it but mainly you need to be around people who are working in this area
Good luck and have fun
"THz wave application is a relatively new topic between microwave and optics, since you can say that THz is a far-infrared lightwave or a very high freqency microwave.
There are many applications about THz, I'm a graduate student studying this topic now.
This is a great site. Maybe I can find someone interested in this topic.
If anyone have interest. I can give some infomation about it. "