pointed across to the other side of the wide bay in front of them, which went down several levels deeper and separated them from the mouth of the larger tunnel that continued from there. "That's the beginning of the second booster chain. The first stage of it is another garden-variety linear accelerator that shoves things up to twenty-five megavolts. The other end of the chain is a fair distance away. In fact it's at that primary storage ring, which you must have noticed as you came over the hill."
"We did," Murdoch said. "So what's the beam up to when it reaches the ring?"
"One hundred billion volts," Mike replied.
Murdoch whistled.
They skirted the bay by way of a railed walkway running around its edge, and came to a concrete apron from which rose the massive steel supports that carried the accelerator tube into the next section of tunnel. From this vantage-point the tube looked like a gigantic gun-barrel converging away into the far distance. The tunnel was wide enough to accommodate an underground roadway that ran along below and to one side of the tube itself. One side of the roadway was flanked by the steel structural work supporting the tube and its coil assemblies, the other by white, tiled wall lined with layers of cable; looking along it, Murdoch felt like a mouse that found its way into a wiring conduit.
A local control center looked out over the bay from a point above the apron and next to the tube. Mike took them up there to meet some of the engineers who were responsible for that section of the plant and able to answer Murdoch's and Lee's more detailed questions. After that the three of them returned to the apron and boarded a small, electrically powered car to continue their tour toward the central zone of the site.
On the way, Mike explained that the same thing happened at all four corners of the plant, yielding four identical beams that entered the primary storage ring at four equispaced points around its circumference. Each corner-battery of four injectors was designed to produce two hundred and forty quad-current-density ion pulses every second, which were then boosted up to virtually the speed of light. Each pulse lasted for just under a half a thousandth of a second, which meant that a pulse would be some sixty-three miles long; obviously, therefore, its leading edge would arrive at the primary ring long before its tail end had emerged from the injectors. The ring drew the pulse in and wrapped it around on itself ten times, rather like a length of string being coiled onto a reel, and in the process multiplied the ion current by a factor of ten. At the same time it merged the compressed pulse with the ten-times-wrapped-around pulses from the three other injector batteries, achieving a final combined current of the order of amperes circulating in the primary ring.
The tunnel opened into a long, wedge-shaped space, again going down to deeper levels, one side of which was formed by the curving wall of the primary ring itself. Above it, the final, one-hundred-billion-volt booster section of the tube continued, suspended amid girders and latticework, to merge into the structure of the ring, thus forming the pointed end of the wedge. From the ends of the chamber, a brightly lit gallery curved away out of sight in both directions to carry the roadway along the ring's periphery, no doubt connecting with other, similar tunnels coming in from the other corners of the site.
"There are four places like this around the whole ring," Mike said as he halted the car to allow them a few minutes to take in the scene. "Every one is an entry port where a combined beam from four injectors is sucked in. There are four exit ports as well, situated between the entry ports. Every time the ring is pumped up, it unloads a full charge through each of the exit ports in turn."
"Like dealing out four hands of cards," Murdoch said. "Yes, we've come across it before."
"You've got it," Mike said, nodding. "Would you like to see one
"We did," Murdoch said. "So what's the beam up to when it reaches the ring?"
"One hundred billion volts," Mike replied.
Murdoch whistled.
They skirted the bay by way of a railed walkway running around its edge, and came to a concrete apron from which rose the massive steel supports that carried the accelerator tube into the next section of tunnel. From this vantage-point the tube looked like a gigantic gun-barrel converging away into the far distance. The tunnel was wide enough to accommodate an underground roadway that ran along below and to one side of the tube itself. One side of the roadway was flanked by the steel structural work supporting the tube and its coil assemblies, the other by white, tiled wall lined with layers of cable; looking along it, Murdoch felt like a mouse that found its way into a wiring conduit.
A local control center looked out over the bay from a point above the apron and next to the tube. Mike took them up there to meet some of the engineers who were responsible for that section of the plant and able to answer Murdoch's and Lee's more detailed questions. After that the three of them returned to the apron and boarded a small, electrically powered car to continue their tour toward the central zone of the site.
On the way, Mike explained that the same thing happened at all four corners of the plant, yielding four identical beams that entered the primary storage ring at four equispaced points around its circumference. Each corner-battery of four injectors was designed to produce two hundred and forty quad-current-density ion pulses every second, which were then boosted up to virtually the speed of light. Each pulse lasted for just under a half a thousandth of a second, which meant that a pulse would be some sixty-three miles long; obviously, therefore, its leading edge would arrive at the primary ring long before its tail end had emerged from the injectors. The ring drew the pulse in and wrapped it around on itself ten times, rather like a length of string being coiled onto a reel, and in the process multiplied the ion current by a factor of ten. At the same time it merged the compressed pulse with the ten-times-wrapped-around pulses from the three other injector batteries, achieving a final combined current of the order of amperes circulating in the primary ring.
The tunnel opened into a long, wedge-shaped space, again going down to deeper levels, one side of which was formed by the curving wall of the primary ring itself. Above it, the final, one-hundred-billion-volt booster section of the tube continued, suspended amid girders and latticework, to merge into the structure of the ring, thus forming the pointed end of the wedge. From the ends of the chamber, a brightly lit gallery curved away out of sight in both directions to carry the roadway along the ring's periphery, no doubt connecting with other, similar tunnels coming in from the other corners of the site.
"There are four places like this around the whole ring," Mike said as he halted the car to allow them a few minutes to take in the scene. "Every one is an entry port where a combined beam from four injectors is sucked in. There are four exit ports as well, situated between the entry ports. Every time the ring is pumped up, it unloads a full charge through each of the exit ports in turn."
"Like dealing out four hands of cards," Murdoch said. "Yes, we've come across it before."
"You've got it," Mike said, nodding. "Would you like to see one
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