This bears closer inspection.
Friday, March 31, 2006
Rough Night with Many Consolations.
The cargo scooter was probably meant for serious purposes, but when you need a break, it's nice to be able to go helling around the lab. And it's a handy way to get laundry back and forth between the beamline where we work and the closet behind the synchrotron power sources where the cleaning staff wash rags and mops. 
Going for a scoot and doing the wash are well-suited to filling all those long stretches while you wait for the spectrum to accumluate.
After a long night, we had the inspiration to melt down a bar of orange chocolate and use up the last of the strawberries. They look very natural, as though they somehow belong among the computers at the beamline desk.
They also made our re-planning powwow more readily bearable. As the sun climbed slowly up the eastern sky, it became clear that the unusual phenomenon we had been tracking for about half the night wasn't especially remarkable after all. We had wasted time. Even when the x-ray beam was far too high energy for this to happen, we continued to see some of the same light we shone onto the sample reflected back out.
Science sidebar It breaks down like this: when we shine our single-color x-ray beam onto a chunk of material, we're especially interested in the x-rays that it emits at lower energy (redder) than we put in. It's called inelastic scatttering because what you put in is different from what comes out, as if you tried playing with a hacky sack the way you would a bouncy red rubber ball; you put in a lot of energy, but the hacky sack would come back with a lot less than you threw it with. Actually, I think I overdid it by picking a hacky sack, but you get the idea. By contrast, a high-bouncing rubber ball would be almost perfectly elastic; after a bounce, it has almost all of the energy it had beforehand. Inelastic x-ray scattering with photons is similar but more interesting because it involves the material's electrons, which are more complicated than walls (in some ways).
So hier goes: At the location of an atom some material, an electron absorbs the energy of the x-ray photon and comes flying out of its comfy little neighborhood into the wide open vacuum the material is parked in. Then any other electrons nearby who have been patiently waiting, stuck at higher energy seats than the one just vacated, can fall down into the hole. They can't just fall to lower energy, though, without getting rid of some energy. Specifically, they have to get rid of the energy difference between their old energy and their comfy new lower energy. (Our universe is fundamentally lazy. Things like to be at low energy, the same way that people like to spend rainy Saturday mornings on the couch with a cup of coffee.) So when that electron relaxes into the hole, that energy has to go somewhere else, and sometimes it's into another x-ray photon, born out of sheer necessity. A lot of the time, this is the red rubber bouncy ball effect, and we get out the same color x-ray we put in. Some of the rest of the time, it's more on the hacky sack side, and we get back light that has less energy than the light that went in. I have friends who will ask, so, yes, sometimes it's possible that you get back a photon with more energy than the one you put in, but that means something in the material gave up energy, and usually if it could do this it already has.
The point is that we expect that the only x-rays the material can emit must come from electrons in the material relaxing down into a hole. They can't have more energy than they get from the most energetic electrons lose when relaxing into the lowest energy hole.
/science sidebar
That's all very fancy, but we were forgetting that this particular chunk of material was made of many, many crystals all pressed into a hard little pellet and baked. When we saw x-rays come out the same energy they went in, it was just x-rays bouncing off the outside of these little crystals. Even when we're putting in such high-energy light that the very highest energy electrons aren't losing a s much energy falling into the hole we've made, the light can still execute an old-fashioned bounce off of these crystals, or penetrate a whole bunch of them before bouncing off of one deep inside the pressed pellet. No quantum mechanics (yup, that was advanced quantum mechanics I was slipping by you if you read the sidebar. Aren't you a smart?), just the usual shit.
So it was with a depressing sensation of having misused our time (and of having failed to think the matter through) that we laid plans to make use of the next day, left Brian to his day shift, and trudged against the commuters to the guest house. You can see now why we needed the chocolate-covered strawberries.
I woke up to another rainy Swedish late afternoon--a terrible time to wake up. Our usual activities in the lab don't involve as much exercise as I'm used to getting, but my dorm room made a nice place to do a few pushups and situps before heading back. 
Walking out in the balmy weather, I wasn't nearly as prepared for the rain as this local. Unless this was another American who was on his way to the pool.
On the way to work I stopped by the ICA for a few necessities. A typical receipt might look like this one, including such commonplace Swedish necessities as glass cookies and Giant Cactus. I think "moms" means "tax"--especially since my mom used to playfully exact food tax in the form of a bit of
whatever ice cream treat we had used her money to purchase at the pool. I miss summer. (You too, Mom!)
We did good work in the early half of the night,
but just a little bit ago we suddenly had no beam, and after calling the techinician discovered that the cooling water for one of the synchrotron's power supplies. It eats a lot of power to get electrons coursing around near the speed of light, even if they ARE lightweight. This means no more new data until after the day shift begins and they can fix the problem. We spent the rest of the night processing the data accumulated thus far, coding procedures for more advanced analysis, ... and taking turns in the massage chair.
From the directions to the massage chair: "Drick ett glas vatten efter massagen. " Evidently Swedish massages have a dehydrating effect. There's so much Science to learn!
The directions in Anglisch also instrukt the user not to be barebacked while using the chair. Their translator should be fired.
I'll blog again when there's time. Thanks for tuning in.
-Dr. S
The cargo scooter was probably meant for serious purposes, but when you need a break, it's nice to be able to go helling around the lab. And it's a handy way to get laundry back and forth between the beamline where we work and the closet behind the synchrotron power sources where the cleaning staff wash rags and mops. 
Going for a scoot and doing the wash are well-suited to filling all those long stretches while you wait for the spectrum to accumluate.
After a long night, we had the inspiration to melt down a bar of orange chocolate and use up the last of the strawberries. They look very natural, as though they somehow belong among the computers at the beamline desk.
They also made our re-planning powwow more readily bearable. As the sun climbed slowly up the eastern sky, it became clear that the unusual phenomenon we had been tracking for about half the night wasn't especially remarkable after all. We had wasted time. Even when the x-ray beam was far too high energy for this to happen, we continued to see some of the same light we shone onto the sample reflected back out.
Science sidebar It breaks down like this: when we shine our single-color x-ray beam onto a chunk of material, we're especially interested in the x-rays that it emits at lower energy (redder) than we put in. It's called inelastic scatttering because what you put in is different from what comes out, as if you tried playing with a hacky sack the way you would a bouncy red rubber ball; you put in a lot of energy, but the hacky sack would come back with a lot less than you threw it with. Actually, I think I overdid it by picking a hacky sack, but you get the idea. By contrast, a high-bouncing rubber ball would be almost perfectly elastic; after a bounce, it has almost all of the energy it had beforehand. Inelastic x-ray scattering with photons is similar but more interesting because it involves the material's electrons, which are more complicated than walls (in some ways). 
So hier goes: At the location of an atom some material, an electron absorbs the energy of the x-ray photon and comes flying out of its comfy little neighborhood into the wide open vacuum the material is parked in. Then any other electrons nearby who have been patiently waiting, stuck at higher energy seats than the one just vacated, can fall down into the hole. They can't just fall to lower energy, though, without getting rid of some energy. Specifically, they have to get rid of the energy difference between their old energy and their comfy new lower energy. (Our universe is fundamentally lazy. Things like to be at low energy, the same way that people like to spend rainy Saturday mornings on the couch with a cup of coffee.) So when that electron relaxes into the hole, that energy has to go somewhere else, and sometimes it's into another x-ray photon, born out of sheer necessity. A lot of the time, this is the red rubber bouncy ball effect, and we get out the same color x-ray we put in. Some of the rest of the time, it's more on the hacky sack side, and we get back light that has less energy than the light that went in. I have friends who will ask, so, yes, sometimes it's possible that you get back a photon with more energy than the one you put in, but that means something in the material gave up energy, and usually if it could do this it already has. 
The point is that we expect that the only x-rays the material can emit must come from electrons in the material relaxing down into a hole. They can't have more energy than they get from the most energetic electrons lose when relaxing into the lowest energy hole. /science sidebar
That's all very fancy, but we were forgetting that this particular chunk of material was made of many, many crystals all pressed into a hard little pellet and baked. When we saw x-rays come out the same energy they went in, it was just x-rays bouncing off the outside of these little crystals. Even when we're putting in such high-energy light that the very highest energy electrons aren't losing a s much energy falling into the hole we've made, the light can still execute an old-fashioned bounce off of these crystals, or penetrate a whole bunch of them before bouncing off of one deep inside the pressed pellet. No quantum mechanics (yup, that was advanced quantum mechanics I was slipping by you if you read the sidebar. Aren't you a smart?), just the usual shit.
So it was with a depressing sensation of having misused our time (and of having failed to think the matter through) that we laid plans to make use of the next day, left Brian to his day shift, and trudged against the commuters to the guest house. You can see now why we needed the chocolate-covered strawberries.
I woke up to another rainy Swedish late afternoon--a terrible time to wake up. Our usual activities in the lab don't involve as much exercise as I'm used to getting, but my dorm room made a nice place to do a few pushups and situps before heading back. 
Walking out in the balmy weather, I wasn't nearly as prepared for the rain as this local. Unless this was another American who was on his way to the pool.
On the way to work I stopped by the ICA for a few necessities. A typical receipt might look like this one, including such commonplace Swedish necessities as glass cookies and Giant Cactus. I think "moms" means "tax"--especially since my mom used to playfully exact food tax in the form of a bit of
whatever ice cream treat we had used her money to purchase at the pool. I miss summer. (You too, Mom!)We did good work in the early half of the night,
but just a little bit ago we suddenly had no beam, and after calling the techinician discovered that the cooling water for one of the synchrotron's power supplies. It eats a lot of power to get electrons coursing around near the speed of light, even if they ARE lightweight. This means no more new data until after the day shift begins and they can fix the problem. We spent the rest of the night processing the data accumulated thus far, coding procedures for more advanced analysis, ... and taking turns in the massage chair.
From the directions to the massage chair: "Drick ett glas vatten efter massagen. " Evidently Swedish massages have a dehydrating effect. There's so much Science to learn!The directions in Anglisch also instrukt the user not to be barebacked while using the chair. Their translator should be fired.
I'll blog again when there's time. Thanks for tuning in.
-Dr. S
Wednesday, March 29, 2006
Night Shift at the Syn chro tron
The spectra were looking good, and all through the house, not another soul was to be found. 
We do all our work in an aluminum tree fort at one end of a long metal pipe branch. The operation of theelectron-filled doughnut (actually a decagon 9 meters on a side) is left to people I never see--and who quite often set the electrons racing around and then leave for the day. All of that is by way of explaining the sense of exploration with which we set out to see if there was access allowed to the center of the ring. Evidently we are permitted to look across the space at the center of the ring but not to descend into it. The giant black bags are collecting the helium and possibly nitrogen which boil off the superconducting magnets. For those who didn't play with Build Your Own Synchrotron kits as a child, magnets do one of two things for you: very carefully made little magnets keep the electrons in nice little bunches as they fly around, and very carefully made giant magnets bend the electrons' path to keep them going in a closed circle. Steering the little suckers around makes them shoot off light in the direction they were going before we pushed on them to bank, and that's the light we use in our experiments. Actually, it's one step more complicated than that: in a straight section of the electron's racetrack (rejstrakk), a whole array of magnets along the top and botttom of this pipe cause the electrons to slalom side to side on their way through, spraying light which goes forward with them but which doesn't curve away as they come into the next bending magnet. Instead it shoots forward into our beamline (really just a metal pipe with some fancy vacuuum pumps hooked to it), bounces off a few mirrors and shiny diffraction gratings, and then slams into a chunk of material we're playing with.
It's not all science as we wandered around the night-empty laboratory: there's art, too.
The big stick wielded by the Swedish lumber industry is such that the lab, part of the national university here in Lund, was required to invest a fraction of the building budget in timber. Because you can only usefully make so many cubicles out of good Swedish plywood (
), there are also some large-scale pieces of what can only be called art. Here Tim gives us a sense of scale for the ode to sailing. I think the title of the piece is translates "Ominous Ebony Wave of Death". My Swedish is rusty, though--meaning nonexistent. We went back to work and dawn found Tim and I sharing a beer.
It was a produktiv nightshift, and the Swedish appreciation of a lax alcohol policy was very much appreciated. Brian (the headless guy adjusting the sample positioning in the chamber) came in to relieve us and we passed the torch.
On the way home, I grabbed a shot of cars in the grocery store parking lot for a friend back home with a preternattural affinity for all things automotive.
Notice that this ICA is a Quantum Tuna, open every day 9am-10pm. This figures large in my schedule, now that I'm only awake for the last four hours of operation.
In the guest house elevator, a warning tone is set for my day's sleep. Recycling can be a dangerous undertaking.
Returning refreshed to the beamline that afternoon, we got to talking about the pros and cons of cats and dogs as pets. In a light Irish accent, imagine hearing the following:
"I'd like a monkey, but I don't like the way their anuses stick out." (BK).
Can you find the leprechaun who said this?
Is the radiation starting to get to us? I certainly hope so.
From the middle of tomorrow night,
-Dr. S
Tuesday, March 28, 2006
Life in Lund.
Sure, it's gloomy-looking in the afternoon, but the birds sing regardless.
Besides which this shot from my window is taken at ~1:30 am on the foggiest day thus far.
I flew into Copenhagen, where you can get a Visa Electron. I thought it would be funnier once I got to the electron structure spectroscopy studies. Then I forgot about it until just now.
Danish trains are models of efficiency-- and they are also model trains. They seem to be made 
by Ikea, in fact. It doesn't amuse Tim (half of Tim appears in the shot of the train doors) after our redeye flights.
The room in the MAX-Lab guest house proved to be a pleasant surprise. Easily the nicest accomodations I've had at any synchotron: a fully equipped communal kitchen which is kept
clean by the mysterious and pervasive Swedish
sense of decency and socialism; a private bathroom; more storage space than my entire three-bedroom apartment back home; and hotel wall art which isn't bland and inoffensive.
When in Tuna (the local neighborhood of the lab in which I'm doing this work), may as well take advantage of local culinary
art. Lunch, for instance, of KraftOst sandwiches (lobster and
cheese in a tube) and leftover fish from last night (a piece of salmon which might have been labeled as salted, so we soaked it and cooked it at the guest house kitchen... and then discovered it was lox) with a side of picked beets. Even our smallish grocery store, conveniently located on the same block as the guest house on the walk to MAX-Lab.
The lab has its own, equally well-equipped, equally equal (in the sense of communal) kitchen, which is good since I'll be spending some 14 hours a day at the lab, and food helps keep you awake and productive.
The coffee machine is free, too, and hosts a long line of cheery science nerds every (weekday) morning. The selections are a bit odd, though they taste just fine. The Wiener Melange isn't nearly as bad a coffee drink as it sounds in English.
Before I give the impression that I came hier only to grow horizontally, at left is the first of the material sample platters I prepared. Its actual scale is about 3cm across. It features boring old calibration samples of zinc (the square metal foil), manganese (the penant-shaped metal slab), and the two materials we're starting with. The greenish shards are MoO3, which should be a one dimensional conductor but isn't. (We'd like to know why.) The pressed powder pellet (try saying that while holding your lips open) is MnVCuO4, a material which is pretty much new to the world and isn't well understood. Pretty much anything we find out will be news.
Sample plates like these we load into steel vacuum chambers, then held in a very intense X-ray beam whose color (/energy) we may sweep through a range, to see the different elements in them absorb the light by coughing up their electrons (in which case we see more electrons flow up from the ground through a wire, and measure that to see how which energies of X-ray get that to happen). Alternatively, we can beam in a single X-ray color, then collect the very, very weak X-rays that come out of the material. It depends a little on direction, too but I'll maybe get to that in a later post.
One last dose of Sweden to chase that shot of Science: The sign on the back of the bathroom door is also good for a cheap mistranslation. Or perhaps the forklifts have higher cosmic significance than I give them credit for.
I'll post again soon.
Senare.
Sure, it's gloomy-looking in the afternoon, but the birds sing regardless.
Besides which this shot from my window is taken at ~1:30 am on the foggiest day thus far.I flew into Copenhagen, where you can get a Visa Electron. I thought it would be funnier once I got to the electron structure spectroscopy studies. Then I forgot about it until just now.
Danish trains are models of efficiency-- and they are also model trains. They seem to be made 
by Ikea, in fact. It doesn't amuse Tim (half of Tim appears in the shot of the train doors) after our redeye flights.The room in the MAX-Lab guest house proved to be a pleasant surprise. Easily the nicest accomodations I've had at any synchotron: a fully equipped communal kitchen which is kept
clean by the mysterious and pervasive Swedish
sense of decency and socialism; a private bathroom; more storage space than my entire three-bedroom apartment back home; and hotel wall art which isn't bland and inoffensive.When in Tuna (the local neighborhood of the lab in which I'm doing this work), may as well take advantage of local culinary
art. Lunch, for instance, of KraftOst sandwiches (lobster and
cheese in a tube) and leftover fish from last night (a piece of salmon which might have been labeled as salted, so we soaked it and cooked it at the guest house kitchen... and then discovered it was lox) with a side of picked beets. Even our smallish grocery store, conveniently located on the same block as the guest house on the walk to MAX-Lab.
The lab has its own, equally well-equipped, equally equal (in the sense of communal) kitchen, which is good since I'll be spending some 14 hours a day at the lab, and food helps keep you awake and productive.
The coffee machine is free, too, and hosts a long line of cheery science nerds every (weekday) morning. The selections are a bit odd, though they taste just fine. The Wiener Melange isn't nearly as bad a coffee drink as it sounds in English.
Before I give the impression that I came hier only to grow horizontally, at left is the first of the material sample platters I prepared. Its actual scale is about 3cm across. It features boring old calibration samples of zinc (the square metal foil), manganese (the penant-shaped metal slab), and the two materials we're starting with. The greenish shards are MoO3, which should be a one dimensional conductor but isn't. (We'd like to know why.) The pressed powder pellet (try saying that while holding your lips open) is MnVCuO4, a material which is pretty much new to the world and isn't well understood. Pretty much anything we find out will be news.
Sample plates like these we load into steel vacuum chambers, then held in a very intense X-ray beam whose color (/energy) we may sweep through a range, to see the different elements in them absorb the light by coughing up their electrons (in which case we see more electrons flow up from the ground through a wire, and measure that to see how which energies of X-ray get that to happen). Alternatively, we can beam in a single X-ray color, then collect the very, very weak X-rays that come out of the material. It depends a little on direction, too but I'll maybe get to that in a later post.
One last dose of Sweden to chase that shot of Science: The sign on the back of the bathroom door is also good for a cheap mistranslation. Or perhaps the forklifts have higher cosmic significance than I give them credit for.
I'll post again soon.
Senare.
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