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Nuclear data explorer · compound nucleus

8Be

8Be is formed when 7Li + p or 7Be + n 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 8Be: entrance pair (rows) and the quantities measured (columns), with the energies covered.

Every EXFOR reaction that forms ⁸Be: entrance pair (rows) and the quantities measured (columns), with the energies covered.
ReactionDatasetsσSσ→Eₓdσ/dΩAyYωγMACSotherFitted in evaluation
7Li(p,α)4He67138.7 keV – 10 MeV128.8 keV – 1.5 MeV1370 keV – 2.1 MeV3521 keV – 19 MeV17.9 MeV – 19 MeV320 keV – 890 keV— (0)— (0)276 keV – 6.9 MeV
7Be(n,p)7Li1988.7 meV – 1.7 MeV— (0)522 meV – 2.5 MeV— (0)— (0)— (0)211 keV – 3.1 MeV2222 meV
7Li(p,n)7Be164281.6 MeV – 170 MeV— (0)211.7 MeV – 670 MeV801.6 MeV – 670 MeV61.7 MeV – 160 MeV91.6 MeV – 330 MeV— (0)— (0)201.6 MeV – 420 MeV
6Li(d,α)4He1591712 keV – 33 MeV713 keV – 740 keV— (0)6022 keV – 33 MeV5867 keV – 8.6 MeV319 keV – 750 keV— (0)— (0)1422 keV – 10 MeV
6Li(d,p)7Li94312 keV – 750 keV— (0)1423 keV – 7.5 MeV6422 keV – 37 MeV467 keV— (0)— (0)— (0)920 keV – 5.3 MeV
7Li(p,inl)562870 keV – 1.6 MeV— (0)8570 keV – 45 MeV34560 keV – 260 MeV357 MeV – 170 MeV— (0)— (0)— (0)9570 keV – 160 MeV
6Li(d,n)7Be501012 keV – 10 MeV197 keV847 keV – 7.5 MeV23150 keV – 37 MeV11.9 MeV – 2.8 MeV— (0)— (0)— (0)736 keV – 2.2 MeV
7Li(p,γ)8Be491380 keV— (0)935 keV – 14 MeV3235 keV – 15 MeV335 keV – 70 keV— (0)— (0)— (0)4130 keV – 1.6 MeV
7Li(p,el)34— (0)— (0)— (0)30210 keV – 170 MeV31.6 MeV – 170 MeV— (0)— (0)— (0)12.6 MeV – 4.7 MeV
4He(α,el)25— (0)— (0)— (0)241.9 MeV – 300 MeV— (0)1320 MeV – 410 MeV— (0)— (0)— (0)8Be
6Li(d,el)20— (0)— (0)— (0)19700 keV – 130 MeV— (0)— (0)— (0)— (0)111 MeV
6Li(d,γ)8Be12— (0)— (0)21.5 MeV – 6.7 MeV31.5 MeV – 10 MeV71.5 MeV – 10 MeV— (0)— (0)— (0)— (0)
6Li(d,inl)12— (0)— (0)12.2 MeV – 7.5 MeV103 MeV – 130 MeV— (0)— (0)— (0)— (0)111 MeV
4He(α,n)7Be11420 MeV – 300 MeV— (0)219 MeV – 99 MeV519 MeV – 140 MeV— (0)— (0)— (0)— (0)— (0)
4He(α,p)7Li11131 MeV – 79 MeV— (0)419 MeV – 300 MeV620 MeV – 140 MeV— (0)— (0)— (0)— (0)— (0)
7Li(p,d)6Li9— (0)— (0)— (0)915 MeV – 670 MeV— (0)— (0)— (0)— (0)— (0)
7Be(n,α)4He8522 meV – 2 MeV— (0)— (0)— (0)— (0)— (0)111 keV – 3.1 MeV11
6Li(d,t)5Li61280 keV – 2.9 MeV— (0)— (0)597 keV – 15 MeV— (0)— (0)— (0)— (0)— (0)
4He(α,3He)5He5— (0)— (0)— (0)259 MeV – 99 MeV— (0)— (0)— (0)— (0)359 MeV
4He(α,d)6Li4199 MeV— (0)131 MeV – 79 MeV231 MeV – 99 MeV— (0)— (0)— (0)— (0)— (0)
4He(α,inl)4— (0)— (0)— (0)132 MeV— (0)— (0)— (0)— (0)332 MeV – 59 MeV
4He(α,γ)8Be2— (0)— (0)29.2 MeV – 14 MeV— (0)— (0)— (0)— (0)— (0)— (0)
7Be(n,el)2— (0)— (0)— (0)— (0)— (0)— (0)211 keV – 3.1 MeV— (0)— (0)
7Be(n,γ)8Be2— (0)— (0)111 meV – 11 keV— (0)— (0)— (0)— (0)1— (0)
4He(α,t)5Li1— (0)— (0)— (0)160 MeV – 99 MeV— (0)— (0)— (0)— (0)— (0)
5He(3He,α)4He1138 keV – 610 keV— (0)— (0)— (0)— (0)— (0)— (0)— (0)— (0)
6Li(d,3He)5He1— (0)— (0)— (0)111 MeV— (0)— (0)— (0)— (0)— (0)
26 more reactions: heavier projectiles, several outgoing particles or inclusive data
26 more reactions: heavier projectiles, several outgoing particles or inclusive data
ReactionDatasetsσSσ→Eₓdσ/dΩAyYωγMACSotherFitted in evaluation
7Li(p,x)117917 keV – 12 MeV— (0)1120 MeV1110 MeV – 560 MeV7340 MeV661.5 MeV – 250 MeV— (0)— (0)2316 MeV – 670 MeV
6Li(d,x)431288 keV – 9.1 MeV— (0)— (0)1288 keV – 9.1 MeV— (0)5120 keV – 770 keV— (0)— (0)1488 keV – 11 MeV
4He(α,x)10431 MeV – 99 MeV— (0)279 MeV – 300 MeV431 MeV – 300 MeV— (0)— (0)— (0)— (0)— (0)
2H(6Li,α)4He9— (0)— (0)— (0)27.6 MeV – 8.1 MeV45.2 MeV— (0)— (0)— (0)316 keV – 1.4 MeV
1H(7Li,α)4He8110 keV – 290 keV210 keV – 290 keV— (0)— (0)— (0)— (0)— (0)— (0)513 keV – 1 MeV
1H(7Li,el)7— (0)— (0)— (0)2290 keV – 8.5 MeV— (0)— (0)— (0)— (0)5290 keV – 980 keV
7Li(p,n+3He)6— (0)— (0)— (0)— (0)— (0)— (0)— (0)— (0)64.1 MeV – 18 MeV
1H(7Li,inl)4— (0)— (0)— (0)— (0)— (0)— (0)— (0)— (0)4290 keV – 680 keV
4He(α,2p)4331 MeV – 140 MeV— (0)— (0)180 MeV – 140 MeV— (0)— (0)— (0)— (0)— (0)
7Li(p,p+t)4— (0)— (0)— (0)— (0)2250 MeV— (0)— (0)— (0)2250 MeV
1H(7Li,p+t)21680 keV— (0)— (0)1680 keV— (0)— (0)— (0)— (0)— (0)
4He(α,n+p)2231 MeV – 99 MeV— (0)— (0)— (0)— (0)— (0)— (0)— (0)— (0)
4He(α,non)22430 keV – 60 MeV— (0)— (0)— (0)— (0)— (0)— (0)— (0)— (0)
6Li(d,he2)2— (0)— (0)— (0)293 MeV – 190 MeV— (0)— (0)— (0)— (0)— (0)
7Be(n,tot)2— (0)— (0)— (0)— (0)— (0)— (0)211 keV – 3.1 MeV— (0)— (0)
7Li(p,γ+α)2— (0)— (0)— (0)23.4 MeV – 26 MeV— (0)— (0)— (0)— (0)— (0)
7Li(p,p+d)2— (0)— (0)— (0)— (0)— (0)— (0)— (0)— (0)2170 MeV
1H(7Li,non)1149 MeV— (0)— (0)— (0)— (0)— (0)— (0)— (0)— (0)
4He(α,2d)1— (0)— (0)— (0)— (0)— (0)— (0)— (0)— (0)159 MeV
4He(α,tot)11430 keV – 1 MeV— (0)— (0)— (0)— (0)— (0)— (0)— (0)— (0)
6Li(d,n+3He)1— (0)— (0)— (0)13.8 MeV— (0)— (0)— (0)— (0)— (0)
7Be(n,0)1— (0)— (0)— (0)— (0)— (0)— (0)1— (0)— (0)
7Be(n,x)1122 meV— (0)— (0)— (0)— (0)— (0)— (0)— (0)— (0)
7Li(p,2p)1— (0)— (0)— (0)— (0)1340 MeV— (0)— (0)— (0)— (0)
7Li(p,non)1122 MeV – 42 MeV— (0)— (0)— (0)— (0)— (0)— (0)— (0)— (0)
7Li(p,pi+x)1— (0)— (0)— (0)1560 MeV— (0)— (0)— (0)— (0)— (0)

Level scheme

Adopted levels of 8Be from ENSDF, with the particle thresholds and the Gamow window of the selected channel drawn across them.

Level scheme
0.0000+3.0302+11.354+16.632+16.922+17.641+18.151+18.912-19.073+19.233+19.401-19.864+20.102+20.200+20.904-21.503(+)22.001-22.0522.242+22.6322.9824.00(1,2)-25.202+25.504+27.490+28.6032.0041.00Gamow window, T₉ = 0.0157S(n) = 18.899 MeVS(p) = 17.254 MeVE (MeV)
  • 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 7Li(p,α)4He threshold (S = 17254 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…

Resonances in the window
E (keV)E_r (keV, c.m.)JπT½ or Γωγ 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 8Be (28)
Levels of ⁸Be
E (keV)JπT½ or Γγ branches
00+Γ = 5.57 eV–
30302+Γ = 1.51 MeV→ 0
113504+Γ = 3.5 MeVEγ 11350
166262+Γ = 108 keV→ 3030, → 0
169222+Γ = 74 keV→ 3030, → 0
176401+Γ = 10.7 keV→ 16922, → 16626, Eγ 14586, → 0
181501+Γ = 138 keV→ 16922, → 16626, Eγ 15095, → 0
189102-Γ = 122 keV→ 16922, → 16626
190693+Γ = 271 keVEγ 16013
192353+Γ = 227 keV–
194001-Γ = 645 keV–
198604+Γ = 700 keV–
201002+Γ = 880 keV–
202000+Γ = 720 keV–
209004-Γ = 1.6 MeV–
215003(+)Γ = 1.1 MeV–
220001-Γ = 4 MeV–
22050–Γ = 270 keV–
222402+Γ = 800 keV–
22630–Γ = 100 keV–
22980–Γ = 230 keV–
24000(1,2)-Γ = 7 MeV–
252002+––
255004+––
27494.10+Γ = 5.5 keV→ 17640
28600–––
32000–Γ = 1 MeV–
41000–––