Light-weight flexible magnetic shields for large-aperture photomultiplier tubes

Photomultiplier Tubes

Light which enters a photomultiplier tube is detected and produces an output signal through the following processes. (1) Light passes through the input window. (2) Light excites the electrons in the photocathode so that photoelectrons are emitted into the vacuum (external photoelectric effect). (3) Photoelectrons are accelerated and focused by the focusing electrode onto the first dynode where ...

Photomultiplier Tubes

including basic and performance. For example, section 4.1 shows spectral response characteristics of typical photocathodes and also gives the definition of photocathode sensitivity and its measurement procedure. Section 4.2 explains dynode types, structures and typical characteristics. Section 4.3 describes various performance characteristics such as time response, operating stability, sensitiv...

Large-volume conventional magnetic shields

2014 Increasing demand for low-field regions of large volumes has resulted in the construction of many magnetically-shielded walk-in rooms. Most have been of the cubic, two-layer high-03BC type, but several have used three layers, including one built by this author about three years ago. This room used several innovations, including "shaking" to increase the permeability of the magnetic sheets....

Improvement of 20 in. diameter photomultiplier tubes

The quality of the 20 in . photomultiplier tubes (Hamamatsu R1449) has been greatly improved over the required specifications for using them m the 50000 ton imaging water Cherenkov detector, Super-Kamiokande . In particular, the resolution of the timing response for single-photoelectron light has been reduced to 3 ns (1Q width), and a clear single-photoelectron peak can be seen in the pulse hei...

Gating Characteristics of Photomultiplier Tubes for Lidar Applications