5 Neutron Spectrum
141
Table 5.9 Threshold energy,
half-life and γ-ray energy of
209 Bi(n, xn) 210−x Bi reactions
(x = 3 to 12) (Ref. [15])
x
Threshold energy
(MeV)
Half-life (T 1/2 ) Emission γ-ray
energy (keV)
3
14.42
38.3 y
569.7 (97.8)
1063.6 (74.9)
4
22.52
6.24 d
803.1 (98.9)
881.1 (66.2)
1718.7 (31.8)
5
29.62
15.31 d
703.4 (31.5)
1763.4 (32.5)
6
38.13
11.22 h
374.8 (81.8)
899.2 (98.5)
983.9 (59.1)
7
45.37
11.76 h
820.2 (29.6)
825.2 (14.6)
1847.3 (11.4)
8
54.24
1.67 h
422.1 (83.7)
658.5 (60.6)
961.7 (99.3)
9
61.69
1.77 h
786.4 (9.5)
935.7 (11.3)
10 70.89
36.45 m
419.7 (91.3)
462.3 (98.3)
1026.4 (100.0)
11 78.47
27.12 m
425.3 (22.0)
560.1 (22.0)
12 87.94
11.85 m
562.4 (79.0)
1063.4 (100.0)
(): Emission rate [%]
Proton beams
Tungsten target
(80 mm diameter, 10 mm thick)
Indium foil
(10 10 1 mm
3 )
Bismuth foil
(50 mm diameter, 3 mm thick)
Stainless
steel flange
Y
X
Z
Fig. 5.5 Experimental setting of activation foils (Bi and In) for measuring the reaction rates at the
target position (Ref. [15])