Experimental study on helical Blumlein line

This paper presents a kind of helical pulse forming line which is designed for a long pulse accelerator. The calculating formulae and the experimental result are both presented. The forming line is charged by a pulse source with a maximum output voltage of 300 kV. The length of helical line is 2.7 m,immersed in the castor oil. The pulse width about 200 ns is obtained. And the characteristic resistance is about 100 ohm. The effects of the switch inductance, charge time and spirality structure on the forming line output pulse are analysed that the helical structure can extend the pulse width efficaciously is proved by experiment.