The Sun radiates 3.9x10E26 joules/second or 3.9x10E23 kilowatts. Just take the area of the sphere at Earth's distance of 150 billion meters and multiply by 1350 watts per square meter. The super-beamrider station that dubbed RAVEN consisting of partial Dyson shells surrounding Sol intercepts just 10% of the Sun's energy, and that's plenty. We don't need all that energy to light our homes and refrigerate our food, so we might as well use it for starflight. Let's examine the case of a 10,000 ton beamrider ship at 66%c. I like 66%c. If you travel to Alpha Centauri at 2/3c, you will get there in 6.5 years, ignoring acceleration and decel for simplicity. The ship time is 4.9 years, almost the same as the number of light years Centauri is from the Sun. So I like 66%c because of this coincidence. To accelerate the 10,000 ton beamrider:
KE=mc^2[{1/(SQRT 1-v2/c2)}-1]
10,000,000 kg.* 300,000,000 m/s^2 [{1/ (SQRT 1- 0.66^2/ 1^2)}-1] = 3E23 joules
Sol radiates 1300 times this energy every second!! So Nature has been provident as she is in so many ways. The RAVEN intercepts enough in one second for 130 of these 10,000 ton vessels but I have conservatively estimated a total system efficiency of 10% for the conversion of light to electricity, transmission to the particle cannons and then conversion of the energy to particle motion or particle kinetic energy. I've been ignoring the inefficiency of the magnetic sails, so I do cheat a little, but this is all close enough for science fiction. Besides, mag-sails could be as efficient as electric motors-90%+. So the Node can propell 13 ships per second to 66%c. Seems like overkill!!
So what if we take a year to reach cruise velocity?
(3x10E23 j)/(3600*24*365)= 9.5x10E15 joules/second or watts
At Mercury, the Sun is about 6.67 times more intense than at Earth, so there's about 9000 watts per square meter. Since I'm allowing 10% efficiency, make it 900 watts.
(9.5x10E15 watts)/900 watts/sq.meter= 1.057x10E13 square meters
That's a square 3251 kilometers on a side or 2015 miles on a side. Heck, we could build this thing on the surface of Mercury and launch a 10,000 ton probe to 66%c every year! In 200 years, I think we could do the job. Solar orbit would probably be a better location than the surface of Mercury.
But 9.5x10E15 joules/second is equal to about 2.3 megatons per second! Hows the ship going to take it? Well, I figure the beamrider's mag-sail generates a field 200 km. diameter. Larger ships generate fields thousands of kilometers wide. That's 31,400 square kilometers or 31.4 billion sq. meters.
(9.5x10E15 watts)/( 3.14x10E10 sq. meters)= 302,547 watts/square meter
That's equal to 224 Suns, and I've read about solar cells under 400 Suns. If solar cells can take that, a sail of some sort can take 224 Suns.
VELOCITY
Chemical
10 kps
Nuclear Thermal
20 kps
Nuclear Electric
50 kps
Solar Sails
?
Mag-sails
?
Fission pulse
1-2%c
Fusion pulse
10%c
Amat fusion pulse
20%c
Amat pulse
30%c
Beamriders
66%c+
Sol
Alpha Centauri 3(G,K,M) 4.3 Sirius(A) 8.6 Epsilon Eridani(K) 10 Epsilon Indi(K) 11 Procyon(F) 11 61 Cygni(K) 11 Tau Ceti(G) 11
Alpha Centauri 3
Sol 4.3 Sirius 9.5 Epsilon Indi 9.6 Epsilon Eridani 12 Tau Ceti 13 Procyon 13 61 Cygni 14
Epsilon Indi
Delta Pavonis(G) 9.1 Beta Hydri(G) 9.3 Tau Ceti 11 Epsilon Eridani 14
Delta Pavonis
Beta Hydri 9.3 Gamma Pavonis(F) 10 R.Cor.Australius(G)14 Zeta Tucanae(F) 13
61 Cygni
Sol 11 Alpha Centauri 3 14 Altair(A) 9.7
Altair
61 Cygni 9.7 Vega(A) 14
Sirius
Sol 8.6 Alpha Centauri 3 9.5 Procyon 5.2 Epsilon Eridani 7.8 Tau Ceti 12
Tau Ceti
Sol 11 Epsilon Eridani 5.4 Epsilon Indi 11 Keid 3(K) 10 82 Eridani(G) 11
Sirius 12 Alpha Centauri 3 13
