A Picosecond Streak Image Tube

A Picosecond Streak Image TubeH. Niu and H. ZhangXian Institute of Optics and Precision Mechanics, Academia Sinica, Xian, Shaanxi,ChinaAbstractA new type of picosecond streak image tube has been developed. The electron optical sys-tem of this tube consists of a curved photocathode, a curved mesh, a spherecal focouselectrode and an anode cone. The deflector with ultroshort parallel plate construction isadopted. S20 photocathode is made on the Cu -Ni mesh substrate having surface resistivityof 300AVrtand with transmissivity of 30% for white light. The measured photosensitivity isup to,140MA /lm. The curved mesh of 50 lines /mm is fabricated by using special technique.P11 phosphor screen is deposited on a fibre faceplate having working area of 'P50 mm. Theobtained static optimum spatial resolution is 40 1p /mm. The deflection sensitivity of thedeflector is 4.2 cm /kv. The magnification of the tube is 2 and it is spatial distortionfree. The dynamic measurements show that at present the temporal resolution reaches 2 psand the useful dynamic range is greater than 256 for the temporal resolution of 10 ps. Theslit streak image curvature phenomena has been eliminated.Design considerationA picosecond streak image tube is an essential part of a picosecond streak camera. Wehavedeveloped a WB -306 picosecond streak image tube with curved photocathode and curved