Antimatter scooping - it's a dangerous game
04 Dec 2018Andrew Linton
Michael Strang settles into the pilot's seat of the heavily modified Type-9, familiarising himself with the additional controls to the left of the throttle. A bank of valve actuators and pump control buttons is topped by digital displays showing pressure and flow rates; they are concerned with distributing the 750 tonnes of hydrogen that the ship has in its cargo hold. Large bore pipes lead away from the hold, feeding a topological tree of ever smaller pipes which carry the fuel towards the surface of the hull. Myriad pores on the hull allow the hydrogen to vent into space.
A row of displays will show the performance of the modified fuel scoop and the levels of gamma radiation at various points. Three graphics of the ship, one looking along each axis, will display the status of the Frost Layer–the all-important barrier between the ship and the antimatter through which it will fly. While the icons are coloured green, the layer is thick enough to protect the ship; amber means the layer is thinning dangerously; red means 'prepare to die'.
Beneath a transparent safety cover, there's a big, red abort button which is programmed to guide the ship away from danger.
Crispin Paunch, Chief Engineer, is double-checking all of the ship's systems.
"She's good to go, son," Paunch says finally. He's grown to admire and respect the younger man, reminding him of his own younger self, and he feels the affection a father has for his children. "Are you sure you want to go through with this? Scooping antimatter is turning out to be far more dangerous than we thought."
"I must," Strang says. "I won't ask anyone to do a job I'm not prepared to do myself. Anyway, I might not like Leiden Frost but I believe his ideas can be put to practical use."
"Aye, well, we'll see."
"You'd better get going if you don't want to come with me."
"Remember," Paunch says, "make a really gentle approach to the corona and don't be afraid to back out as soon as there are difficulties. The thrusters will behave differently in the hydrogen-antihydrogen annihilation cloud, and the temperature will rise more than you're used to. Keep it below ninety percent if you can."
They shake hands and Paunch leaves the bridge; a few minutes later his ship-launched fighter departs and Strang is alone.
Setting ten percent thrust, Strang approaches Thequa AA-A j0, a star which has the spectral signature and luminosity of a class M red dwarf. However, this star is different; it's an antimatter star at the centre of an antimatter system. He recalls the first time he read the system description and how he was excited by its possibilities.
In its core, antihydrogen fuses into antihelium. The system has three terrestrial planets in which antisilicate minerals combine to form antibasalt lava flows and antigranitic intrusions. An antiammonia world lies outside the orbits of two gas giants composed principally of antihydrogen. Much further out there's an antineutron star.
It isn't known who was the first discoverer of the system, or the second or the third; it was only known that a considerable number of commanders had disappeared without trace in this region of space. It is suspected that they had tried to scoop fuel or land on one of the planets, and were annihilated by contact with antimatter.
It was only when two commanders travelling together arrived in system that its nature was discovered. One of them perished during fuel scooping and the survivor carried the knowledge with him.
For the flight recorder, Strang announces each of his actions.
"Hydrogen venting initiated…flow set to half-a-tonne per second…automatic distribution programme started…temperature at forty-five percent."
The theory of the Frost Layer is that a protective barrier can be created between a ship and the antihydrogen in the star's corona by enveloping the ship in a cloud of hydrogen. The hydrogen and antihydrogen are annihilated in a burst of energy and this creates enough pressure to keep antimatter away from the hull.
Early trials had shown that the layer does exist; where they had failed was in maintaining a thick enough layer for long enough to scoop antihydrogen into the containment unit that sits alongside the conventional fuel tank.
"Temperature at fifty percent…Frost Layer detected…status nominal…flow increased to one tonne per second."
The Type-9 starts to vibrate as the Frost Layer develops. Strang lifts the cover on the abort button.
"Temperature at sixty-five percent…fuel scooping started…zero point five tonnes per second."
It was working; antihydrogen was flowing into the containment unit.
"Now, let's see what this thing can do," he says, pushing the stick forwards gently, ever so gently.
"Venting increased to one point five tonnes per second…temperature at seventy-five percent…scooping at zero point seven five tonnes per second."
The vibration is stronger now; two of the status icons flicker between green and amber, then one of them switches to a steady amber. The sound of rushing hydrogen through the elaborate pipework changes to a more urgent tone as the real-time distributor software responds to the thinning of the Frost Layer on the surface of the T9 facing away from the star.
"Venting at two tonnes per second…temperature ninety-five percent…scooping at one point one…containment seventy-five percent full…we've done it, we've scooped antihydrogen!"
The excitement in Strang's voice is clear, but also the tension.
"Your too hot," Paunch says over the comms. "Time to get out of there."
"Negative," Strang says, "I want to fill the containment unit."
He maintains the attitude of the ship and turns up the venting flow rate. There are still three hundred tonnes of hydrogen in the hold, so he should be able to keep going.
"Temperature critical!" the COVAS reports. All three status icons are solid amber, then one of them flickers into the red. The sound of venting hydrogen changes tone again in response.
Strang looks at the temperature and hears soon after: "Taking damage."
"Temperature at one-oh-five…and…containment full."
He's elated, momentarily. The original concept, the development of the technology, all that work, has paid off.
A big, red message splashes across the HUD: "Warning! Hydrogen pumps at 50%."
"Time to go," Strang says for the log.
"Gently, no sudden movement that would create turbulence," Paunch advises. "Bring her out as gently as you went in. You have to keep the Frost Layer intact."
"Understood. We have amber status across the board. I've maximised the flow of hydrogen."
The Type-9 climbs slowly away from the star, sparks flying across the cockpit and small whiffs of smoke drifting up. The hull looks black and pitted, and there are places where panels are buckled slightly–but she survived an encounter with antimatter.
Strang returns to his own ship and enters the bridge. Paunch is there, so is Gantt, the project manager, and Leiden H. Frost.
"I did it!" Frost says. "I'll get the prize for physics this year, for sure."
"And delivered with full functionality, on time, and within budget," Gantt gushes. "The next project must be to develop an improved antimatter propulsion system."
"Yes, it works," Paunch says, stepping forwards to take Strang's hand.
But he stops abruptly when he sees the gun that Strang is wielding.
"Yes, we have a way to scoop antihydrogen from this star…so what do I need you for?"
Twenty seconds later Strang is the only living soul on the bridge.