(Thermal) Neutron Capture Radiohalo Manufacturing Chain:  Copyright (c) 1992
___________________________________________________________ by John Brawley

    204 Pb  (Stable nonradiogenic 'original' lead)
     +n |
    205 Pb (3 x 10^7 Y)-EC-> 205 Tl [Stable]-n-> 206 Tl (4.19 min) -B--> |
     +n |                 _(NonÄCyclic: once only)_______________________|
--> 206 Pb  (Stable) <---|
|    +n |                     *-------------------*   L|  n =neutron
|   207 Pb  (Stable) <---|   | REQUIREMENTS:     |   E|  a =Alpha Decay
|    +n |                C    | 1) Neutron Flux   |   G|  B- =Beta Decay
C   208 Pb  (Stable)     y    | 2) Lead particles |   E|  m =Isomer
y    +n |                c    | 3) Geologic time  |   N|  mb =millibarns
c   209 Pb (3.3 Hr)      l    *-------------------*   D|  EC =Electron Capture
l    B- |                i
i   209 Bi  (Stable)     c---------------------------------------------|
c    +n |                |---------<--B- 207 Tl (4.8 min)----------|   |
|   210m Bi(3 x 10^6 Y)-n-> 211 Bi (2.15 Min)-a-> (84%) 6.622 MEV -|   |
|   210 Bi (5 Days)                           or  (16%) 6.278 MEV -|   |
|    B- |                                                              |
|   210 Po (138 Days) -n-> (30 mb) 211 Po (.52 sec)-a-> 7.445 MEV -|---|
|     a |                  (.5 mb) 211m Po (25 sec) or  7.278 MEV -|
|_______| 5.30 MEV [Inner Halo]