starship-design: Apology

["L. Parker" <lparker@cacaphony.net>]

Gee, I think I owe someone an apology for a joking remark
about transporting antimatter...

QUOTE BEGINS HERE------------------------------------------------
We are presently building a portable antiproton trap. [Ref. 3, 4] 
It is designed to carry up to 10+9 antiprotons for 10 days. A 
schematic drawing of the trap is shown in Figure 5. It is a 
prototype for a trap, not necessarily any larger, capable of 
carrying 10+14 antiprotons for up to 120 days (duration of a 
round trip mission to Mars). Since earlier experiments at LEAR 
have demonstrated antiproton lifetimes up to two months, we are 
confident we can achieve this goal.


<Picture>

Figure 5 - Portable Antiproton Trap


The portable trap is one meter tall, 30 cm across, and weighs 
55 kg. It operates at 4 K temperature, supported by cryogenic 
nitrogen and helium reservoirs, and has a unique feature that 
the confining magnet is made of permanently magnetic SmCo 
materials, which should prove to be robust. This trap is 
currently being tested, and will then be sent to CERN for a 
fill and demonstration journey across Europe. Figure 6 shows 
a photograph of the trap under test in the Penn State 
laboratories.


<Picture>

Figure 6 - Portable Penning Trap Under Test at Penn State

An alternate method for transporting large numbers of antiprotons 
into space utilizes Radiofrequency Quadrupole (RFQ) Storage Rings. 
A schematic view of a ring is shown in Figure 7. Pulsed bunches of 
antiprotons of 2.5 keV energy are injected into the ring (top), 
where they are captured and rotated by electric forces amongst the 
four electrodes (bottom).


<Picture>

Figure 7 - Schematic of Radiofrequency Quadrupole (RFQ) Storage 
Ring


We have designed a set of 20 such rings, capable of transporting 
a total of one microgram of antiprotons into space for long periods 
of time. The rings are shown in Figure 8, with specifications given 
in Table 1. To stand back from the space charge limit for constant 
number of antiprotons, and to reduce power loading to the antiproton 
plasma (<1 kW), injection of positrons into the rings with 
superconducting RF would be desirable. This system is sized to be 
transportable on the U.S. Interstate Highway System, after loading 
of antiprotons at Fermilab over a period of several months.\

QUOTE ENDS HERE----------------------------------------------------

And I thought the idea was crazy.....I hereby retract my earlier snide 
remarks about transporting black holes, I'm now certain SOMEONE is planning
to transport blackholes also.

Lee

                                                          (o o)
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There is nothing so big or so crazy that one out of a million technological
societies may not feel itself driven to do, provided it is physically 
possible.

Freeman Dyson, 1965