Question

How do we produce very high voltages up to range of million volts for experiments ???

Answer 1

use an induction coil (also called Ruhmkorff coil)
http://en.wikipedia.org/wiki/Induction_coil

Answer 2

using transformer will be easiest option

Answer 3

but, transformers only step-up AC voltages

Answer 4

and even by using induction coil, it will work same because in both transformer and induction coil same principle is used of Mutual induction.......
Or if you want to convert DC then use Bipolar transistor Circuit

Answer 5

Van de graff generator can be used.. they can produce voltage up to million volts..

Answer 6

using van de graff generator.