In a Roentgen tube (used to produce X-Rays), what is the significance of anti-cathode, cathode, and anode??

Dear Student,

In Roentgen tube, anti cathode and anode are one and the same thing. The anode is also called as anti cathode. 
Significance of anode or anti-cathode :

1. It increases the life of tube.
2. The discharge becomes more smooth and hence the intensity of X-ray beam is more constant.

Significance of cathode :
The function of cathode is to expel the electrons and focus them into well defined beam at the anode.