2.8 Criticality and Yield: Approximate Methods
109
0
200
400
600
800
50
55
60
65
70
Tamper mass (kg)
Core mass (kg)
U-235 + WC
no compression
R = 3 cm
2.5 cm
2.75 cm
2.25 cm
2 cm
1.5 cm
Fig. 2.22 Expansion distances to second criticality for given core/tamper mass combinations for a
235 U core and WC tamper, assuming no initial compression and same expansion distance for both
core and tamper
0
10
20
30
40
50
60
70
80
50
55
60
65
70
Yield (kt)
Core mass (kg)
U-235 + WC
no compression
R = 3 cm
2.5 cm
2.75 cm
2.25 cm
2 cm
1.5 cm
Fig. 2.23 Yield curves corresponding to Fig. 2.22. Yields are computed using total core plus tamper
mass in (2.142)