As reported in NewScientist,
Murray hacked his amps to produce a gadget that can hold atoms still while he bashes them with beams of electrons. Until now, it has been possible to hold atoms still, or hit them with such beams, but not both at the same time.
Cooling and trapping atoms at temperatures close to absolute zero has produced many insights into physics, and may be critical to the development of quantum computers.
Unfortunately, the force field of lasers and magnetic fields needed to hold atoms still is not compatible with flying beams of electrons or ions. So the only way to study the effect of blasting atoms with such beams has been to do it when the atoms are moving, and this leads to smeared out collisions and Doppler effects that are hard to interpret.
Hitting atoms with a beam shortly after switching off a trap does help. But it takes up to 20 milliseconds for magnetic fields to stop sloshing around inside an atom trap, Murray says, and by that time the atoms have started moving again.
Finding a way to kill those magnetic fields instantly and hit atoms before they start moving has been troubling physicists for years. One solution, Murray realised, is to use the speaker coil from a high power PA amplifier to produce the magnetic fields inside the trap.
Unlike the coils traditionally used by physicists, which are driven by direct current, an audio speaker voice coil is fed by an alternating current. It smoothly cycles between inducing positive and then negative magnetic currents in the trap. At the end of each complete cycle - which takes five milliseconds to complete - the positive and negative currents cancel each other out and there is no net magnetic current.
So if the researchers cut the power precisely at that point they can entirely avoid magnetic currents rippling through the trap.
To read the entire article click here. Thanks to SoundMan Rick Earl for sending this in.
We have just set up an Ebay merchant account to handle selling any used gear we that we have available. Most of you already know that we generally don’t sell used gear but we do occasionally have used or demo items in great shape and we have decided to open this account handle these items. Of course feel free to come by the store to inspect anything we have up for sale but to buy it you will need to purchase it from our Ebay account. You can get to it by clicking here. I have a couple of items up now and have more to add in the next couple of days. I will also post an Ebay alert here in the news section whenever I add new items.
Free 40 Track Digital Recording System Software
Buy a Roland V-Mix Standard System form us between Now and December 23 for the low price of $11,995.00 and we will upgrade the system with a copy of Cakewalk Sonar REAC, the 40 ch live recording software package a $1,295.00 value for FREE.
System must be for immediate shipment and not a part of any other system package or special offer. Shipping not included.
I just spotted this in The Washington Times. A German production company was given $700,000.00 to provide production for Obama when he appeared in Berlin this summer. Our congratulations to the SoundMan who sold that show. We hear that he is now retired and living on his own private island somewhere in the Pacific.
Great gig if you
can get it.
(Click to enlarge)