Breakdown characteristics of cryogenic gaseous helium in uniform electric field and space charge modified non-uniform field

✍ Scribed by M. Hara; J. Suehiro; H. Matsumoto

• Publisher: Elsevier Science
• Year: 1990
• Tongue: English
• Weight: 786 KB
• Volume: 30
• Category: Article
• ISSN: 0011-2275
• DOI: 10.1016/0011-2275(90)90276-i

✦ Synopsis

D.c. breakdown characteristics of gaseous helium in uniform and non-uniform electric fields down to 4.2 K at atmospheric pressure have been investigated. Although helium is a nonelectronegative gas, a negative pulse corona is observed only near the normal boiling point due to the abrupt appearance of quasi-bubble state electrons. Positive ion space charge modifies the electric field distribution in the gap space considerably. The electric field strength on the non-corona electrode in the ion flow field is measured satisfactorily and analysed theoretically using a numerical electric field calculation technique. On the basis of experimental results, methods are proposed to give corona onset criteria and the breakdown voltage preceded by a positive glow corona.