Cloud Chamber Photograph Positron Lead plate Larger curvature

Cloud Chamber Photograph Positron Lead plate Larger curvature of particle above plate means it’s moving slower (lost energy as it passed through) 2022/1/16 Carl Anderson 1905 -1991

正电子产生 lb+-decay l pair production (g -> e+ + e-) 2022/1/16

(22 Na -> 22 Ne + e+ + ue + g (1. 28 Me. V)) 2022/1/16

Positronium Classical picture n Quantum picture e- density e+ density joint density 2022/1/16

n The resulting approximation for the ground-state energy of positronium is -6. 811 ± 5. 05× 10 -4 e. V, which agrees favorably with the accepted value of 6. 805 e. V. 2022/1/16

2022/1/16

2022/1/16

2022/1/16

2022/1/16

2022/1/16

2022/1/16

2022/1/16

提高峰底比~105 2022/1/16

2 D-PALS 2022/1/16

2022/1/16

2022/1/16

Table shows typical values for the efficiency, emission energy and energy spread of selected materials and different geometries. 2022/1/16

2022/1/16

2022/1/16

Cross-sectional view of the chopper and buncher. 2022/1/16

2022/1/16

2022/1/16

2022/1/16