Nuclear data explorer · compound nucleus
8B
8B is formed when 7Be + p fuse. Its levels just above each threshold are the resonances that set those reactions' rates.
Channels and what has been measured
Every EXFOR reaction that forms 8B: entrance pair (rows) and the quantities measured (columns), with the energies covered.
| Reaction | Datasets | σ | S | σ→Eₓ | dσ/dΩ | ωγ | other | Fitted in evaluation |
|---|---|---|---|---|---|---|---|---|
| 7Be(p,γ)8B | 32 | 11120 keV – 8.8 MeV | 20110 keV – 3 MeV | 1 | — (0) | — (0) | — (0) | |
| 7Be(p,el) | 5 | — (0) | — (0) | — (0) | 5370 keV – 3.6 MeV | — (0) | — (0) | |
| 7Be(p,inl) | 3 | — (0) | — (0) | — (0) | 31.5 MeV – 2.3 MeV | — (0) | — (0) |
5 more reactions: heavier projectiles, several outgoing particles or inclusive data
| Reaction | Datasets | σ | S | σ→Eₓ | dσ/dΩ | ωγ | other | Fitted in evaluation |
|---|---|---|---|---|---|---|---|---|
| 1H(7Be,γ)8B | 8 | 11.5 MeV | 1300 keV | — (0) | — (0) | — (0) | 6370 keV – 990 keV | |
| 1H(7Be,el) | 7 | — (0) | — (0) | — (0) | 2530 keV – 6.4 MeV | 1 | 4470 keV – 3.2 MeV | |
| 1H(7Be,inl) | 3 | — (0) | — (0) | — (0) | 11.3 MeV – 3.1 MeV | — (0) | 21.1 MeV – 3.2 MeV | |
| 1H(7Be,0) | 1 | — (0) | — (0) | — (0) | — (0) | 1 | — (0) | |
| 1H(7Be,x) | 1 | 1 | — (0) | — (0) | — (0) | — (0) | — (0) |
Level scheme
Adopted levels of 8B from ENSDF, with the particle thresholds and the Gamow window of the selected channel drawn across them.
- level in the window with a measured ωγ
- level in the window with no ωγ in EXFOR
- Jπ in parentheses or in italics is tentative.
Resonances in the window
Levels between the 7Be(p,γ)8B threshold (S = 136.37 keV) and the top of the Gamow window at T9 = 0.0157 (50 keV above it), with the resonance strengths ωγ EXFOR holds for them.
Looking for measured strengths…
| E (keV) | E_r (keV, c.m.) | Jπ | T½ or Γ | ωγ measured |
|---|---|---|---|---|
| ENSDF lists no level in this window. | ||||
A strength is matched to a level when its resonance energy plus the threshold lies within max(3 keV, 3σ) of the level energy.
Levels of 8B (5)
| E (keV) | Jπ | T½ or Γ | γ branches |
|---|---|---|---|
| 0 | 2+ | T½ = 770 ms | – |
| 769.5 | 1+ | Γ = 35.6 keV | → 0 |
| 2320 | 3+ | Γ = 350 keV | → 0 |
| 3500 | 2- | Γ = 8 MeV | – |
| 10619 | 0+ | Γ = < 60 keV | – |