CDI simulation in PSPICE

Hi, having trouble simulating a simple CDI cicuit in PSPICE. Im sure the thyristor/scr is correct for the job, as it is used in lots of other cdi circuits. The pulse supply doesn't bias the scr as it should, 200V remains across it. I've experimented by putting a current limiting resistor in series with the scr but the 200V just appears across this and the scr just switches the remaining couple of volts. There is definatly something wrong with my configuration im sure.
Any help, info appreciated.
Ben

how are you meant to insert pics, im new to this. I just uploaded a file...then nothing.

Some of the sites features are broken... They are fixing them as we speak