B2. A ten-stage photomultiplier tube (PMT) has a photo-receiving area of 0.5 cm². All of the dynodes are equally spaced
Posted: Wed May 04, 2022 1:11 pm
B2. A ten-stage photomultiplier tube (PMT) has a photo-receiving area of 0.5 cm². All of the dynodes are equally spaced by 5 mm and subjected to the same potential difference. The response time of the PMT is characterized to be 15 ns. The dark current of the PMT is 1.0 nA. The external quantum efficiency EQE is 90% and the secondary emission ratio of the dynodes follows the expression 8 = AV, where A = 0.6 and ε = 0.7. (a) Describe the working principle of the PMT and draw a schematic diagram for its structure. (4 marks) (b) Determine the total working voltage of the PMT. (4 marks) (c) Calculate the gain of the PMT. (4 marks) (d) Explain whether the PMT can detect single photon per second. (3 marks)