Difference between revisions of "Fusion Propulsion"

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Fusion Propulsion
 
Fusion Propulsion
 +
{| class="wikitable"
 +
| colspan="16" rowspan="1" |Table 1 - Significant fusion reactions
 +
|-
 +
| colspan="4" rowspan="1" |Reaction
 +
|→
 +
| colspan="9" rowspan="1" |Products
 +
|Total
 +
Energy release
 +
|Atomic mass of products
 +
|-
 +
|
 +
| colspan="3" rowspan="1" |
 +
|
 +
|
 +
|ratio
 +
|MeV/ fusion
 +
|
 +
|
 +
|MeV/ fusion
 +
|
 +
|
 +
|MeV/ fusion
 +
|GJ/kg
 +
|N
 +
|-
 +
|1
 +
|D
 +
| +
 +
|T
 +
|→
 +
|He4
 +
|100%
 +
|3.49
 +
| +
 +
|n0
 +
|14.1
 +
|
 +
|
 +
|
 +
|340 000
 +
|5
 +
|-
 +
|2a
 +
|D
 +
| +
 +
|D
 +
|→
 +
|He3
 +
|50%
 +
|0.82
 +
| +
 +
|n0
 +
|2.45
 +
|
 +
|
 +
|
 +
|79 000
 +
|4
 +
|-
 +
|2b
 +
|
 +
| +
 +
|D
 +
|→
 +
|T
 +
|50%
 +
|01.01
 +
| +
 +
|p+
 +
|03.02
 +
|
 +
|
 +
|
 +
|97 000
 +
|4
 +
|-
 +
|3
 +
|D
 +
| +
 +
|He3
 +
|→
 +
|He4
 +
|100%
 +
|3.6
 +
| +
 +
|p+
 +
|14.7
 +
|
 +
|
 +
|
 +
|353 000
 +
|5
 +
|-
 +
|4
 +
|T
 +
| +
 +
|T
 +
|→
 +
|He4
 +
|100%
 +
|
 +
| +
 +
|2x n0
 +
|
 +
|
 +
|
 +
|11.3
 +
|182 000
 +
|6
 +
|-
 +
|5
 +
|He3
 +
| +
 +
|He3
 +
|→
 +
|He4
 +
|100%
 +
|
 +
| +
 +
|2x p+
 +
|
 +
|
 +
|
 +
|12.9
 +
|207 000
 +
|6
 +
|-
 +
|6a
 +
|He3
 +
| +
 +
|T
 +
|→
 +
|He4
 +
|
 +
|
 +
| +
 +
|n+
 +
|12.1
 +
| +
 +
|p+
 +
|
 +
|195 000
 +
|6
 +
|-
 +
|6b
 +
|
 +
| +
 +
|T
 +
|→
 +
|He4
 +
|
 +
|4.8
 +
| +
 +
|D
 +
|9.5
 +
|
 +
|
 +
|
 +
|230 000
 +
|6
 +
|-
 +
|6c
 +
|
 +
| +
 +
|T
 +
|→
 +
|He4
 +
|
 +
|0.5
 +
| +
 +
|n0
 +
|1.9
 +
| +
 +
|p+
 +
|11.9
 +
|230 000
 +
|6
 +
|-
 +
|7a
 +
|D
 +
| +
 +
|Li6
 +
|→
 +
|He4
 +
|
 +
|
 +
| +
 +
|He4
 +
|
 +
|
 +
|
 +
|22.4
 +
|270 000
 +
|8
 +
|-
 +
|7b
 +
|
 +
| +
 +
|Li6
 +
|→
 +
|He3
 +
|
 +
|
 +
| +
 +
|He4
 +
|
 +
| +
 +
|n0
 +
|2.56
 +
|31 000
 +
|8
 +
|-
 +
|7c
 +
|
 +
| +
 +
|Li6
 +
|→
 +
|Li7
 +
|
 +
|
 +
| +
 +
|p+
 +
|
 +
|
 +
|
 +
|5.0
 +
|60 000
 +
|8
 +
|-
 +
|7d
 +
|
 +
| +
 +
|Li6
 +
|→
 +
|Be7
 +
|
 +
|
 +
| +
 +
|n0
 +
|
 +
|
 +
|
 +
|3.4
 +
|41 000
 +
|8
 +
|-
 +
|8
 +
|p+
 +
| +
 +
|Li6
 +
|→
 +
|He4
 +
|
 +
|1.7
 +
| +
 +
|He3
 +
|2.3
 +
|
 +
|
 +
|
 +
|55 000
 +
|7
 +
|-
 +
|9
 +
|n
 +
| +
 +
|Li6
 +
|→
 +
|He4
 +
|
 +
|
 +
| +
 +
|T
 +
|2.3
 +
|
 +
|
 +
|
 +
|
 +
|7
 +
|-
 +
|10
 +
|He3
 +
| +
 +
|Li6
 +
|→
 +
|He4
 +
|
 +
|
 +
| +
 +
|He4
 +
|
 +
| +
 +
|p+
 +
|16.9
 +
|181 000
 +
|9
 +
|-
 +
|11
 +
|p+
 +
| +
 +
|B11
 +
|→
 +
|3x He4
 +
|
 +
|
 +
|
 +
|
 +
|
 +
|
 +
|
 +
|8.7
 +
|70 000
 +
|12
 +
|-
 +
|12
 +
|6D
 +
|
 +
|
 +
|→
 +
|2x He4
 +
|
 +
|8.92
 +
| +
 +
|2n0
 +
|16.55
 +
| +
 +
|2p+
 +
|17.72
 +
|348 000
 +
|12
 +
|-
 +
| colspan="16" rowspan="1" |Total energy release = sum of energies (MeV) x 1.6e-19 J/eV / mass of reaction products
 +
Mass of reaction products = N x atomic mass unit (1.66e-27 kg)
 +
In a fusion reaction, the portion of the fuel that actually reacts is called the burnup fraction. As a first order of magnitude evaluation, we can establish that a fusion drive with a burnup fraction of 10%, using 1 kg of deuterium+he3 per second will produce 353 000 GJ/kg x 1kg/s x 0,1 = 35 300 GW of power (Line 4, table 1).
 +
To find the thrust from the fusion reaction, F=ṁ*2Pt*ηn . For an efficiency (ηn) of 80%, the force is 5 600 KN or 576 tonnes.
 +
To find the exhaust velocity Ve=F/ṁ= 56 500 000 N / 1 kg/s = 5 650 000 m/s
 +
|}
 
[[Category:Propulsion]]
 
[[Category:Propulsion]]

Revision as of 06:52, 2 September 2021

Fusion Propulsion

Table 1 - Significant fusion reactions
Reaction → Products Total

Energy release

Atomic mass of products
ratio MeV/ fusion MeV/ fusion MeV/ fusion GJ/kg N
1 D + T → He4 100% 3.49 + n0 14.1 340 000 5
2a D + D → He3 50% 0.82 + n0 2.45 79 000 4
2b + D → T 50% 01.01 + p+ 03.02 97 000 4
3 D + He3 → He4 100% 3.6 + p+ 14.7 353 000 5
4 T + T → He4 100% + 2x n0 11.3 182 000 6
5 He3 + He3 → He4 100% + 2x p+ 12.9 207 000 6
6a He3 + T → He4 + n+ 12.1 + p+ 195 000 6
6b + T → He4 4.8 + D 9.5 230 000 6
6c + T → He4 0.5 + n0 1.9 + p+ 11.9 230 000 6
7a D + Li6 → He4 + He4 22.4 270 000 8
7b + Li6 → He3 + He4 + n0 2.56 31 000 8
7c + Li6 → Li7 + p+ 5.0 60 000 8
7d + Li6 → Be7 + n0 3.4 41 000 8
8 p+ + Li6 → He4 1.7 + He3 2.3 55 000 7
9 n + Li6 → He4 + T 2.3 7
10 He3 + Li6 → He4 + He4 + p+ 16.9 181 000 9
11 p+ + B11 → 3x He4 8.7 70 000 12
12 6D → 2x He4 8.92 + 2n0 16.55 + 2p+ 17.72 348 000 12
Total energy release = sum of energies (MeV) x 1.6e-19 J/eV / mass of reaction products

Mass of reaction products = N x atomic mass unit (1.66e-27 kg) In a fusion reaction, the portion of the fuel that actually reacts is called the burnup fraction. As a first order of magnitude evaluation, we can establish that a fusion drive with a burnup fraction of 10%, using 1 kg of deuterium+he3 per second will produce 353 000 GJ/kg x 1kg/s x 0,1 = 35 300 GW of power (Line 4, table 1). To find the thrust from the fusion reaction, F=ṁ*2Pt*ηn . For an efficiency (ηn) of 80%, the force is 5 600 KN or 576 tonnes. To find the exhaust velocity Ve=F/ṁ= 56 500 000 N / 1 kg/s = 5 650 000 m/s

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