Probably not mercury rectifiers or thyratrons, but hydrogen and deuterium thyratrons do (edit - emit X-rays, that is). They're much higher voltage devices. Exam

Probably not mercury rectifiers or thyratrons, but hydrogen and deuterium thyratrons do (edit - emit X-rays, that is). They're much higher voltage devices. Example at [1] [1] https://www.e2v.com/shared/content/resources/File/documents/thyratrons/cx1725a_cx1725ax.pdf https://www.e2v.com/shared/content/resources/File/documents/...