| 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 |
| square femtometer | 100 fm2 | 200 fm2 | 300 fm2 | 400 fm2 | 500 fm2 | 600 fm2 | 700 fm2 | 800 fm2 | 900 fm2 | 1 000 fm2 | 1 100 fm2 | 1 200 fm2 | 1 300 fm2 | 1 400 fm2 | 1 500 fm2 | 1 600 fm2 | 1 700 fm2 | 1 800 fm2 | 1 900 fm2 | 2 000 fm2 | 2 100 fm2 | 2 200 fm2 | 2 300 fm2 | 2 400 fm2 | 2 500 fm2 | 2 600 fm2 | 2 700 fm2 | 2 800 fm2 | 2 900 fm2 | 3 000 fm2 | 3 100 fm2 | 3 200 fm2 | 3 300 fm2 | 3 400 fm2 | 3 500 fm2 | 3 600 fm2 | 3 700 fm2 | 3 800 fm2 | 3 900 fm2 | 4 000 fm2 | 4 100 fm2 | 4 200 fm2 | 4 300 fm2 | 4 400 fm2 | 4 500 fm2 | 4 600 fm2 | 4 700 fm2 | 4 800 fm2 | 4 900 fm2 | 5 000 fm2 | 5 100 fm2 | 5 200 fm2 | 5 300 fm2 | 5 400 fm2 | 5 500 fm2 | 5 600 fm2 | 5 700 fm2 | 5 800 fm2 | 5 900 fm2 | 6 000 fm2 | 6 100 fm2 | 6 200 fm2 | 6 300 fm2 | 6 400 fm2 | 6 500 fm2 | 6 600 fm2 | 6 700 fm2 | 6 800 fm2 | 6 900 fm2 | 7 000 fm2 | 7 100 fm2 | 7 200 fm2 | 7 300 fm2 | 7 400 fm2 | 7 500 fm2 | 7 600 fm2 | 7 700 fm2 | 7 800 fm2 | 7 900 fm2 | 8 000 fm2 | 8 100 fm2 | 8 200 fm2 | 8 300 fm2 | 8 400 fm2 | 8 500 fm2 | 8 600 fm2 | 8 700 fm2 | 8 800 fm2 | 8 900 fm2 | 9 000 fm2 | 9 100 fm2 | 9 200 fm2 | 9 300 fm2 | 9 400 fm2 | 9 500 fm2 | 9 600 fm2 | 9 700 fm2 | 9 800 fm2 | 9 900 fm2 | 10 000 fm2 |
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 | square femtometers | barns | square femtometers |
|---|---|---|---|
| 1 | = 100 | 6 | = 600 |
| 2 | = 200 | 7 | = 700 |
| 3 | = 300 | 8 | = 800 |
| 4 | = 400 | 9 | = 900 |
| 5 | = 500 | 10 | = 1000 |
Square femtometre or Square femtometer is a SI prefixes applied unit of area, symbol fm2, is a multiple of the of SI prefixes (femto) used with the metre.
| Name of unit | Symbol | Definition | Relation to SI units | Unit System |
|---|---|---|---|---|
| square femtometer | fm2 | ≡ 1 fm × 1 fm ≡ 10-15 m × 10-15 m | = 10-30 m2 | Metric system SI |
| square femtometers | barns | square femtometers | barns |
|---|---|---|---|
| 1 | = 0.01 | 6 | = 0.06 |
| 2 | = 0.02 | 7 | = 0.07 |
| 3 | = 0.03 | 8 | = 0.08 |
| 4 | = 0.04 | 9 | = 0.09 |
| 5 | = 0.05 | 10 | = 0.1 |
| barns | square femtometers |
|---|---|
| 1 | = 100 |
| 0.01 | = 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 …) |