Section 2 Technology

Section 2.2 The Matter Antimatter Reaction Assembly

The warp engines are fuelled by plasmas, energised from energy created in matter antimatter reactions in the warp core. The fuel for these reactions is stored in the primary deuterium tank in the ship’s stardrive section. The tanks are loaded with deuterium at 13.8 K (Sternbach and Okuda 1991) which is 4.57 K below the freezing point of deuterium. (18.37 K). The supply is held in compartmentalised tanks within the main body tank to prevent loss due to damage. The total internal volume is some 63,200 m3 but is more normally loaded to a volume of 62,500 m3. These tanks have a rated loss below 0.0002 kg/day.

Though we know the volume, for matter antimatter reactions we need an approximation of the total mass. Given that the deuterium is in a slush form below its freezing point we can use an approximation of its density as:

 0.1967 gram per cubic centimetre

For the creation of energies the matter reactant is forced in to the core through an injector from deck 30 (Galaxy Class) to meet in the reaction chamber with antimatter (anti-deuterium) from deck 42. The anti-deuterium is stored in thirty 100m3 pods giving a total storage capacity of 3,0000m3.

 In the core dilithium filters anti-deuterium and deuterium to create a maximised reaction. When bringing the reaction chamber up to levels for warp flight a ratio of reactant (matter) to reactant (antimatter) is about 25:1. Though one would expect the annihilation ratio to be 1:1 it is likely that there is some degree of matter loss or matter destruction that is not involved in the reaction. When breaking the warp one limit this loss drops to 10:1. the matter antimatter ratio changes to increasingly more efficient values up to warp 8 where the ratio stabilises at 1:1 and remains at this level for all speeds above warp 8. Engine efficiency of the starship and the resultant energies from matter annihilation is very high of the order of 97%. In 2370 Chief Engineer Geordie LaForge increased the power conversion levels to 97.2%

Galaxy Class fuel storage for three year mission disregarding refueling, bussard collector usage or antimatter creation using onboard antimatter generators.

 

3000 m3 of antimatter and

62,500 m3 of deuterium

 

Given a loss rate of 0.00002 kg/day of deuterium over the 3 year mission

365.256*3 = 1095.768

1095.768 * 0.00002 = 0.0219 kg

 

For or our hypothetical situation we can assume anti-matter to be the limiting factor on mission length. The Galaxy Class project was designed to have an operational life of three years at warp six before fuel exhaustion. This means that after three years the fuel will be consumed, we interpret this, given the nature of reactions, to mean that the antimatter will be depleted first with the possibility of redundant deuterium left.

 

To calculate the energy released during the mission aiming for fuel exhaustion in three years we must estimate fuel mass.

 

Total mass of deuterium:

 

62,500,000,000 * 0.1967 = 12,293,750,000 grams

12,293,750 Kg

minus the loss over the period:

12,293,750Kg – 0.0219Kg = 12,293,749.9781 Kg

Given that there are

86,164.0905 (seconds) * 1095.768 (days)

2,265,980,474.856096 seconds in the three-year period

Matter reacting is:          2 *(12293749.9781) = 24,587,499.9562 Kg

(Assuming 1 part matter 1 part antimatter. As we have discussed this is not necessarily so and there will be deuterium waste, additional matter that is not annihilated. However, given that we started with such an excess of deuterium and that the level of reactants must be lower than the ratio 10:1, we can ignore the imbalance, also as discussed below should deuterium run low, there exists a supply of liquid deuterium approximating, 297,600 Kg [9,300*32] of liquid fuel that can be fed into the reactor)

Also note: there are thirty two cryo tanks in the saucer section module. these function as auxiliary fuel supplies, however the fuel is not in the same physical state. The auxiliary tanks store deuterium in a liquid state. The Volume of each tank is 113 cubic metres and each is capable of storing 9.3 metric tonnes of fuel. This means that the density in these pods must be far lower than in the PDT. 

 

Specifically

 

9,300 Kg / 113 = 82.3 kg/m3 or 0.0823 gram per cubic centimetre. This is less than 2.39 times the density of the main PDT tank, and is very much less than the typical Density of liquid deuterium which is around 0.1630 grams per cubic centimetre but does closely approximate with the liquid density of hydrogen 0.07099 g/cm3. The only feasible explanation is that the material has a density comparable to liquid deuterium but the tanks are not filled to capacity. This may be similar to the PDT which have an internal volume of  63,200 m3 but which are more normally loaded to a volume of 62,500 m3. This ratio of volume to load is far higher than for the secondary tanks and might suggest the need for more safety measures in the primary hull.

 

Using the Matter from the Primary fuel supply only we can calculate the energy output of the warp core.

By E=mc2

E(joules) = 24,587,499.9562 (kg) * (299 792 500 )2 (ms-1)

E(joules) = 2,209,814,910,958,998,089,136,250

Over the duration of the mission this gives

2,209,814,910,958,998,089,136,250 (joules) / 2,265,980,474.856096 (seconds)

975,213,571,113,994.3617 joules per second

 

975.214  Terrawatts  (3 d.p.)

Given the loss of energy of 2.8% (100-97.2 efficiency) this gives:

A loss of 27.305992 terrawatts over the mission duration:

947.908 Terrawatts (3 d.p.) Total useable power created in the M/ARA.

 

It could be argued that an integral is required to take account of the effect reduced mass has on the ship, in that as the mission continues the ship will become lighter and more easily propelled. We assume that the mass of fuel is negligible compared to the overall space frame and that the SIF field reduces apparent starship mass to avoid relativistic effects.

 

In comparison to the energy released in the M/ARA the systems on the former Cardassian station DS9 consists of six fusion reactors supplies an energised plasma to the station.  The maximum output for all these working in concert is 790 terrawatts, a value roughly comparable to the output of a M/ARA on a Galaxy Class starship. Though the Deep Space Nine core is many times larger, the values represent the efficiency of the two systems with matter energy conversion being far higher in a Galaxy Class ship.

 

Energy Requirements for Deep Space Operation 

For a standard three year mission, many other systems would need considerable energy including environmental and replicator systems. However, in contrast the ship would very likely drop from warp on several occasions for extended periods of time for this operation. We assume that our vessel is running in a form of grey-mode for a three year flight where energy requirements are for propulsion only. We hope that this in someone balances with the environmental system requirements:

 

Main Deflector Dish

For warp flight we must consider the energy required for the main deflector. Even if all other systems are minimal the main deflector must continually be powered or else the ship could suffer a catastrophic failure. We can assume that for velocities below warp 8 (those that we are concerned with) only one generator is operational (page 88) This means we feed 6 128 MW generators. This is 768 MW, but we can reduce this to 80% efficiency:

80% normal output = 614.4MW

 

Structural Integrity Field

During normal space flight one field generator must be active in each hull. Each generator consists of a cluster of twenty 12 MW graviton generators. Therefore we must allow power for 40 *12MW generators. This is 480 MW of power. In addition There are four subspace distortion amplifiers in use cooled by 300,000 mega joule per hour coolant systems. This is 4 * 83.34 Mgawatt = 333.34 Megawatts.

This means 813.34 Megawatts must be tied into the SIF field.

 

Deflector shields

For normal cruise functions one generator in each of the three major areas must be functioning, these include:

Primary Hull, Secondary Hull and one each for the nacelles. The normal cruise mode requires the combined generators to output 1152 MW.

 

To keep the ship operating we need at least:

614.4 + 813.34 + 1152 = 2579.74 MW

This is 2.258 Giga Watts.

 

This number is insignificant compared to the energy output of the core.

 

947,908 Giga watts – 2.258 Giga watts = 947,905.75 Giga watts

 

For a three year mission averaging warp 6 velocities until fuel exhaustion 947.905 Terrajoules per second are required.

 

However:

By the Warp speed power graph (Sternbach and Okuda 1991pg.55) warp 6 has a power usage of approximately 3,000,000 mega joules per cochrane.

 

This equates to:

392 * 3 terrajoules = 1176 terrajoules

 

which matches quite closely with the assumptions of a warp 6 flight for 3 years:

 

975.211 (terra watts) / 1176 (terrajoules) = 80.6% of the three year mission.

Which is 2 years 5 months 12 days and 4 hours 45 minutes and 24 seconds.

 

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