| barn | 1 b | 2 b | 3 b | 4 b | 5 b | 6 b | 7 b | 8 b | 9 b | 10 b | 11 b | 12 b | 13 b | 14 b | 15 b | 16 b | 17 b | 18 b | 19 b | 20 b | 21 b | 22 b | 23 b | 24 b | 25 b | 26 b | 27 b | 28 b | 29 b | 30 b | 31 b | 32 b | 33 b | 34 b | 35 b | 36 b | 37 b | 38 b | 39 b | 40 b | 41 b | 42 b | 43 b | 44 b | 45 b | 46 b | 47 b | 48 b | 49 b | 50 b | 51 b | 52 b | 53 b | 54 b | 55 b | 56 b | 57 b | 58 b | 59 b | 60 b | 61 b | 62 b | 63 b | 64 b | 65 b | 66 b | 67 b | 68 b | 69 b | 70 b | 71 b | 72 b | 73 b | 74 b | 75 b | 76 b | 77 b | 78 b | 79 b | 80 b | 81 b | 82 b | 83 b | 84 b | 85 b | 86 b | 87 b | 88 b | 89 b | 90 b | 91 b | 92 b | 93 b | 94 b | 95 b | 96 b | 97 b | 98 b | 99 b | 100 b |
| attobarn | 1.0 × 1018 ab | 2.0 × 1018 ab | 3.0 × 1018 ab | 4.0 × 1018 ab | 5.0 × 1018 ab | 6.0 × 1018 ab | 7.0 × 1018 ab | 8.0 × 1018 ab | 9.0 × 1018 ab | 1.0 × 1019 ab | 1.1 × 1019 ab | 1.2 × 1019 ab | 1.3 × 1019 ab | 1.4 × 1019 ab | 1.5 × 1019 ab | 1.6 × 1019 ab | 1.7 × 1019 ab | 1.8 × 1019 ab | 1.9 × 1019 ab | 2.0 × 1019 ab | 2.1 × 1019 ab | 2.2 × 1019 ab | 2.3 × 1019 ab | 2.4 × 1019 ab | 2.5 × 1019 ab | 2.6 × 1019 ab | 2.7 × 1019 ab | 2.8 × 1019 ab | 2.9 × 1019 ab | 3.0 × 1019 ab | 3.1 × 1019 ab | 3.2 × 1019 ab | 3.3 × 1019 ab | 3.4 × 1019 ab | 3.5 × 1019 ab | 3.6 × 1019 ab | 3.7 × 1019 ab | 3.8 × 1019 ab | 3.9 × 1019 ab | 4.0 × 1019 ab | 4.1 × 1019 ab | 4.2 × 1019 ab | 4.3 × 1019 ab | 4.4 × 1019 ab | 4.5 × 1019 ab | 4.6 × 1019 ab | 4.7 × 1019 ab | 4.8 × 1019 ab | 4.9 × 1019 ab | 5.0 × 1019 ab | 5.1 × 1019 ab | 5.2 × 1019 ab | 5.3 × 1019 ab | 5.4 × 1019 ab | 5.5 × 1019 ab | 5.6 × 1019 ab | 5.7 × 1019 ab | 5.8 × 1019 ab | 5.9 × 1019 ab | 6.0 × 1019 ab | 6.1 × 1019 ab | 6.2 × 1019 ab | 6.3 × 1019 ab | 6.4 × 1019 ab | 6.5 × 1019 ab | 6.6 × 1019 ab | 6.7 × 1019 ab | 6.8 × 1019 ab | 6.9 × 1019 ab | 7.0 × 1019 ab | 7.1 × 1019 ab | 7.2 × 1019 ab | 7.3 × 1019 ab | 7.4 × 1019 ab | 7.5 × 1019 ab | 7.6 × 1019 ab | 7.7 × 1019 ab | 7.8 × 1019 ab | 7.9 × 1019 ab | 8.0 × 1019 ab | 8.1 × 1019 ab | 8.2 × 1019 ab | 8.3 × 1019 ab | 8.4 × 1019 ab | 8.5 × 1019 ab | 8.6 × 1019 ab | 8.7 × 1019 ab | 8.8 × 1019 ab | 8.9 × 1019 ab | 9.0 × 1019 ab | 9.1 × 1019 ab | 9.2 × 1019 ab | 9.3 × 1019 ab | 9.4 × 1019 ab | 9.5 × 1019 ab | 9.6 × 1019 ab | 9.7 × 1019 ab | 9.8 × 1019 ab | 9.9 × 1019 ab | 1.0 × 1020 ab |
A barn (symbol: b) is a unit of area equal to 10−28 m2 (100 fm2). Originally used in nuclear physics for expressing the cross sectional area of nuclei and nuclear reactions, today it is also used in all fields of high-energy physics to express the cross sections of any scattering process, and is best understood as a measure of the probability of interaction between small particles.
| Name of unit | Symbol | Definition | Relation to SI units | Unit System |
|---|---|---|---|---|
| barn | b | ≡ 10−28 m2 | ≡ 10−28 m2 | Nuclear Physics |
| barns | attobarns | barns | attobarns |
|---|---|---|---|
| 1 | ≡ 1.0E+18 | 6 | ≡ 6.0E+18 |
| 2 | ≡ 2.0E+18 | 7 | ≡ 7.0E+18 |
| 3 | ≡ 3.0E+18 | 8 | ≡ 8.0E+18 |
| 4 | ≡ 4.0E+18 | 9 | ≡ 9.0E+18 |
| 5 | ≡ 5.0E+18 | 10 | ≡ 1.0E+19 |
A attobarn (symbol: ab) is a unit of area equal to 10−46 m2.
| Name of unit | Symbol | Definition | Relation to SI units | Unit System |
|---|---|---|---|---|
| attobarn | ab | ≡ 10−46 m2 | ≡ 10−46 m2 | Nuclear Physics |
| attobarns | barns | attobarns | barns |
|---|---|---|---|
| 1 | ≡ 1.0E-18 | 6 | ≡ 6.0E-18 |
| 2 | ≡ 2.0E-18 | 7 | ≡ 7.0E-18 |
| 3 | ≡ 3.0E-18 | 8 | ≡ 8.0E-18 |
| 4 | ≡ 4.0E-18 | 9 | ≡ 9.0E-18 |
| 5 | ≡ 5.0E-18 | 10 | ≡ 1.0E-17 |
| barns | attobarns |
|---|---|
| 1 | ≡ 1.0 × 1018 |
| 1.0 × 10-18 | ≡ 1 |
| Symbol | Definition |
|---|---|
| ≡ | exactly equal |
| ≈ | approximately equal to |
| = | equal to |
| digits | indicates that digits repeat infinitely (e.g. 8.294 369 corresponds to 8.294 369 369 369 369 …) |