#helium
Helium Bath Splash: Physicists Discover Surprising Phenomenon
While working with helium nanodroplets, scientists at the Department of Ion Physics and Applied Physics led by Fabio Zappa and Paul Scheier have come across a surprising phenomenon: When the ultracold droplets hit a hard surface, they behave like drops of water. Ions with which they were previously doped thus remain protected on impact and are not neutralized.
At the Department of Ion Physics and Applied Physics, Paul Scheier’s research group has been using helium nanodroplets to study ions with methods of mass spectrometry for around 15 years. Using a supersonic nozzle, tiny, superfluid helium nanodroplets can be produced with temperatures of less than one degree Kelvin. They can very effectively be doped with atoms and molecules. In the case of ionized droplets, the particles of interest are attached to the charges, which are then measured in the mass spectrometer. During their experiments, the scientists have now stumbled upon an interesting phenomenon that has fundamentally changed their work. “For us, this was a gamechanger,” says Fabio Zappa from the nano-bio-physics team. “Everything at our lab is now done with this newly discovered method.” The researchers have now published the results of their studies in Physical Review Letters.
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A vial containing ultrapure helium gas. Like other gases, an electric current can make the usually colorless helium glow.
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Helium is the second element on the periodic table. It has two protons, two neutrons, and two electrons. It is one of only three elements that were created in the big bang, and, after hydrogen, is the second most abundant element in the universe.
On the periodic table, it falls into the group of noble gases, the right most column, or group. The noble gases are all odorless, colorless gases that are extremely nonreactive or chemically inert. This is because the outer valence electron shells of these gases are already filled and helium doesn’t need to bond with other atoms to get a full set of electrons.
Helium is a monoatomic gas, meaning it usually exists as individual helium atoms. This is especially true because it is a noble gas and does not bond easily with other molecules.
Despite it’s abundance in the universe, helium is relatively rare on Earth. Helium is light enough to escape the Earth’s atmosphere and so there is very little left. Most of the helium that is found on Earth today is a result of the radioactive decay of other elements.
Physicists advance high temperature superconducters for many potential applications
ByKim McDonald-
Physicists at UC San Diego have developed a new way to control the transport of electrical currents through high-temperature superconductors—materials discovered nearly 30 years ago that lose all resistance to electricity at commercially attainable low temperatures.
Their achievement, detailed in two separate scientific publications, paves the way for the development of sophisticated electronic devices capable of allowing scientists or clinicians to non-invasively measure the tiny magnetic fields in the heart or brain, and improve satellite communications.
“We believe this new approach will have a significant and far-reaching impact in medicine, physics, materials science and satellite communications,” said Robert Dynes, a professor of physics and former Chancellor of UC San Diego.
READ MORE ON UC SAN DIEGO
Ref: YBa2Cu3O7− δ superconducting quantum interference devices with metallic to insulating barriers written with a focused helium ion beam. Applied Physics Letters (2015) | http://dx.doi.org/10.1063/1.4922640
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Helium ‘balloons’ offer new path to control complex materials
Researchers at the Department of Energy’s Oak Ridge National Laboratory have developed a new method to manipulate a wide range of materials and their behavior using only a handful of helium ions.
The team’s technique, published in Physical Review Letters, advances the understanding and use of complex oxide materials that boast unusual properties such as superconductivity and colossal magnetoresistance but are notoriously difficult to control.
For the first time, ORNL researchers have discovered a simple way to control the elongation of a crystalline material along a single direction without changing the length along the other directions or damaging the crystalline structure. This is accomplished by adding a few helium ions into a complex oxide material and provides a never before possible level of control over magnetic and electronic properties.
“By putting a little helium into the material, we’re able to control strain along a single axis,” said ORNL’s Zac Ward, who led the team’s study. “This type of control wasn’t possible before, and it allows you to tune material properties with a finesse that we haven’t previously had access to.”
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Hexagonal boron nitride semiconductors enable cost-effective detection of neutron signals
One of the most critical issues the United States faces today is preventing terrorists from smuggling nuclear weapons into its ports. To this end, the U.S. Security and Accountability for Every Port Act mandates that all overseas cargo containers be scanned for possible nuclear materials or weapons.
Detecting neutron signals is an effective method to identify nuclear weapons and special nuclear materials. Helium-3 gas is used within detectors deployed in ports for this purpose.
The catch? While helium-3 gas works well for neutron detection, it’s extremely rare on Earth. Intense demand for helium-3 gas detectors has nearly depleted the supply, most of which was generated during the period of nuclear weapons production during the past 50 years. It isn’t easy to reproduce, and the scarcity of helium-3 gas has caused its cost to skyrocket recently – making it impossible to deploy enough neutron detectors to fulfill the requirement to scan all incoming overseas cargo containers.
Helium-4 is a more abundant form of helium gas, which is much less expensive, but can’t be used for neutron detection because it doesn’t interact with neutrons.
“What I initially thought looked like the result of a computer simulation, is in fact a 1970’s photograph of a test of a shuttle model in a Mach 20 helium wind tunnel, using electron beam fluorescence.” — Scott Manley, https://youtu.be/v0Z_4VyuzcA
Also relating to this tweet by Scott Manley https://twitter.com/djsnm/status/1445874000521953282
“A model of the space shuttle in the Langley 22-inch helium tunnel at Mach 20. The flow is made visible by bombardment of an electron beam.”
—https://history.nasa.gov/SP-440/ch7-4.htm
Image lifted from this Reddit post, being the largest resolution version (3000×2400 px) that I could find https://www.reddit.com/r/space/comments/57ip4z/space_shuttle_wind_tunnel_test_using_electron_beam/
Cryopump on a sputter system.
Cryopumps are a common type of high vacuum pump. They operate by condensing or freezing gases in the vacuum chamber onto an array that is typically cooled down to 10-12 kelvin. Compressed helium gas enters a chamber below the condenser array, where a piston (the displacer) allows the gas to expand, removing heat from the system. The piston then pushes the helium out and back into a compressor, and the cycle repeats. The displacer and compressor in a cryopump make a distinctive rhythmic high pitched whistle that is a common sound in clean rooms and condensed matter physics labs.
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Finished - Helium
I really like how this one turned out. Onward to hydrogen!
WIP - Helium
I tried a different approach to colour this one. So far I like it but it takes a bit more time than usual. It also doesn’t help that I’m right now learning how to crochet and grew a bit addicted to it XD
Lineart - Helium
I won’t do all elements but those I get ideas for/ find interesting
Instagram: sarahurie
Balloon Pyro floating above the battlefield, what will he do~?
AirShip !
AirYacht’s partners Guillaume Hoddé and Matthieu Ozanne have collaborated with designer Franck Darnet for the concept.
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Bullet Passing Through Helium-Filled Soap Bubble (1970)
Gelatin silver print
Harold Edgerton (1903 - 1990)
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Set of photographs by A. Haziot shows single crystals of helium 4 with various orientations near 20 mK.
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THIS IS
THE CUTEST MAKEOUT SCENE EVER
BRUH
DFJHFJJGJJHKGFJHFD
OH MY GOD THE ONE
THE ONLY
THE CARRY THAT APPEARS IN EVERY FIC EVER /POS
THE BRIDAL-STYLE CARRY
The cutest gays i ever did see <33333
so ur telling me
Dream jumped into the ocean
AT MIDNIGHT
and couldn’t see anything below the water
and got stung and could’ve died????
This shit is why i have thalassophobia-
Dream
babe
take a breath love
he’s okay <3 He’s right in front of you
He’s letting Dream use the CAMERA DJHNFHHGG
‘Morning goes in a loving slowness his house has never known, and afternoon comes with paint.’
Oh, damn you for being so poetic with this- /pos
OH MY GOD THIS IS REALLY HAPPENING
HOW DO I BREATHE PROPERLY AGAIN UHHHHHH
/pos
THEY ARE NOT ABOUT TO GET SPICY ON STREAM-
I SWEAR TO GOD-
THAT GOT SPICY REAL QUICK OMG DHDHFJGFNMJGF
BRO THE EMOTIONS?? TBHYL IS AN AMAZING WRITER, OH MY GOD
AND THEN IT GOT SERIOUS AND IM ON THE EDGE OF MY FUCKING SEAT
“Words, George. I’ll do anything for you. Tell me. Anything.”
George meets his eyes, breathes when he breathes, and pleads, “Just have me.”
IM GONNA CRY /POS
“Say it back,” Dream pleads. “You need me, too.”
The next line
will either make or break me
I HAVE BEEN MADE, BESTIES
AND NOW IM ABOUT TO PISS MYSELF LAUGHING, GODDAMIT SAPNAP LMFAOOOO /POS
“Say it back,” Dream pleads. “You need me, too.”
The next line
will either make or break me
THIS IS
THE CUTEST MAKEOUT SCENE EVER
BRUH
DFJHFJJGJJHKGFJHFD
IM
IM LOSING MY MINDDDDD
AAAAAAAAAAAAHHHHHHHHHHHHHHHHHH
JDKFGVBRKJTFRSJKSDL
THEM-
