Nuclear data explorer · compound nucleus
4He
4He is formed when 2H + 2H 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 4He: entrance pair (rows) and the quantities measured (columns), with the energies covered.
| Reaction | Datasets | σ | S | dσ/dΩ | Ay | Y | MACS | other | Fitted in evaluation |
|---|---|---|---|---|---|---|---|---|---|
| 2H(d,n)3He | 145 | 272.4 keV – 99 MeV | 132.4 keV – 1.5 MeV | 69900 eV – 50 MeV | 1811 keV – 130 MeV | 2250 keV – 79 MeV | 2 | 142.4 keV – 2.5 MeV | |
| 2H(d,p)3H | 140 | 242 keV – 6.9 MeV | 211.2 keV – 1500 MeV | 393.5 keV – 42 MeV | 447.2 keV – 130 MeV | 23.5 keV – 50 keV | 1 | 91.3 keV – 150 keV | |
| 3H(p,n)3He | 93 | 23760 keV – 15 MeV | — (0) | 55760 keV – 230 MeV | 12960 eV – 12 MeV | — (0) | — (0) | 3820 keV – 9.3 MeV | |
| 2H(d,γ)4He | 52 | 510 keV – 7.3 MeV | 57 keV – 7.3 MeV | 1720 keV – 47 MeV | 2120 keV – 47 MeV | — (0) | — (0) | 47 keV – 310 keV | |
| 2H(d,el) | 46 | — (0) | — (0) | 3324 keV – 110 MeV | 131.5 MeV – 110 MeV | — (0) | — (0) | — (0) | |
| 3He(n,el) | 45 | 1017 meV – 22 MeV | — (0) | 9750 keV – 22 MeV | 20710 keV – 16 MeV | — (0) | 1 | 517 meV – 19 meV | |
| 3H(p,γ)4He | 35 | 310 keV – 22 MeV | 29 keV – 100 keV | 2610 keV – 270 MeV | 230 MeV – 270 MeV | — (0) | — (0) | 21.5 MeV – 6.7 MeV | |
| 3He(n,p)3H | 29 | 1219 meV – 24 MeV | — (0) | 675 keV – 210 MeV | — (0) | — (0) | 7 | 4200 eV – 210 MeV | |
| 3H(p,el) | 25 | — (0) | — (0) | 1937 keV – 430 MeV | 62.2 MeV – 14 MeV | — (0) | — (0) | — (0) | |
| 3He(n,γ)4He | 22 | 919 meV – 3 MeV | — (0) | 619 meV – 13 MeV | — (0) | — (0) | 630 keV | 16.7 MeV | |
| 3He(n,d)2H | 11 | 53.3 MeV – 52 MeV | — (0) | 63.3 MeV – 52 MeV | — (0) | — (0) | — (0) | — (0) | |
| 1H(t,n)3He | 7 | — (0) | — (0) | 71.5 MeV – 29 MeV | — (0) | — (0) | — (0) | — (0) | |
| 1H(t,el) | 3 | — (0) | — (0) | 3160 keV – 18 MeV | — (0) | — (0) | — (0) | — (0) | |
| 3H(p,d)2H | 2 | — (0) | — (0) | 210 MeV – 14 MeV | — (0) | — (0) | — (0) | — (0) | |
| 3He(n,inl) | 1 | — (0) | — (0) | 13 MeV | — (0) | — (0) | — (0) | — (0) |
15 more reactions: heavier projectiles, several outgoing particles or inclusive data
| Reaction | Datasets | σ | S | dσ/dΩ | Ay | Y | MACS | other | Fitted in evaluation |
|---|---|---|---|---|---|---|---|---|---|
| 2H(d,n+p) | 45 | — (0) | — (0) | 61.7 MeV – 26 MeV | 106 MeV – 130 MeV | — (0) | — (0) | 293.4 MeV – 79 MeV | |
| 3He(n,tot) | 27 | 170.23 meV – 30 MeV | — (0) | — (0) | 21.5 MeV – 5.6 MeV | — (0) | 8 | — (0) | |
| 2H(d,x) | 24 | 115 MeV – 99 MeV | — (0) | 48.3 MeV – 26 MeV | 3130 MeV | 34 MeV – 9.5 MeV | — (0) | 13250 keV – 18 MeV | |
| 3He(n,ths) | 5 | — (0) | — (0) | — (0) | — (0) | — (0) | — (0) | 58.3 meV – 19 meV | |
| 2H(d,eta) | 4 | 1 | — (0) | 2 | 1 | — (0) | — (0) | — (0) | |
| 3He(n,n+p) | 4 | — (0) | — (0) | 211 MeV | — (0) | — (0) | — (0) | 25.9 MeV – 18 MeV | |
| 2H(d,tot) | 3 | 3430 keV – 1 MeV | — (0) | — (0) | — (0) | — (0) | — (0) | — (0) | |
| 3H(p,n+p) | 3 | — (0) | — (0) | 18.9 MeV | — (0) | — (0) | — (0) | 28.1 MeV – 11 MeV | |
| 3H(p,x) | 3 | — (0) | — (0) | 27.3 MeV – 37 MeV | — (0) | — (0) | — (0) | 17.3 MeV – 11 MeV | |
| 3He(n,2n+p) | 3 | 210 MeV – 22 MeV | — (0) | 111 MeV | — (0) | — (0) | — (0) | — (0) | |
| 2H(d,2n+p) | 1 | — (0) | — (0) | — (0) | 199 MeV – 130 MeV | — (0) | — (0) | — (0) | |
| 2H(d,non) | 1 | 11 MeV | — (0) | — (0) | — (0) | — (0) | — (0) | — (0) | |
| 3H(p,2n+p) | 1 | — (0) | — (0) | — (0) | — (0) | — (0) | — (0) | 18.4 MeV – 11 MeV | |
| 3He(n,abs) | 1 | — (0) | — (0) | — (0) | — (0) | — (0) | 1 | — (0) | |
| 3He(n,non) | 1 | 15.9 MeV – 18 MeV | — (0) | — (0) | — (0) | — (0) | — (0) | — (0) |
Level scheme
Adopted levels of 4He 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 2H(d,n)3He threshold (S = 23847 keV) and the top of the Gamow window at T9 = 0.8 (204 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 4He (16)
| E (keV) | Jπ | T½ or Γ | γ branches |
|---|---|---|---|
| 0 | 0+ | – | – |
| 20210 | 0+ | Γ = 500 keV | – |
| 21010 | 0- | Γ = 840 keV | – |
| 21840 | 2- | Γ = 2.01 MeV | – |
| 23330 | 2- | Γ = 5.01 MeV | – |
| 23640 | 1- | Γ = 6.2 MeV | – |
| 24250 | 1- | Γ = 6.1 MeV | – |
| 25280 | 0- | Γ = 7.97 MeV | – |
| 25950 | 1- | Γ = 12.7 MeV | – |
| 27420 | 2+ | Γ = 8.69 MeV | – |
| 28310 | 1+ | Γ = 9.89 MeV | – |
| 28370 | 1- | Γ = 3.92 MeV | – |
| 28390 | 2- | Γ = 8.75 MeV | – |
| 28640 | 0- | Γ = 4.89 MeV | – |
| 28670 | 2+ | Γ = 3.78 MeV | – |
| 29890 | 2+ | Γ = 9.72 MeV | – |