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Scientists develop a new tool for measuring radio waves in fusion plasmas – Newswise

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Newswise — Scientists seeking to bring to Earth the fusion energy that drives the sun and stars use radio frequency (RF) waves — the same waves that bring radio and television into homes — to heat and drive current in the plasma that fuels fusion reactions. Scientists now have developed a path-setting way to measure the waves that could be used to validate predictions of their impact, setting the stage for enhanced future experiments that could result in bringing energy from fusion to Earth.

Potential breakthrough

The potential breakthrough, led by researchers at the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL), could lead to follow-up experiments on the National Spherical Tokamak Experiment-Upgrade (NSTX-U), the flagship fusion experiment at PPPL that is undergoing repair, as well as other fusion facilities around the world. “If our method turns out to work it would be a very useful tool for many fusion reactors,” said Grant Rutherford, a first-year graduate student at the Massachusetts Institute of Technology (MIT) and lead author of a paper in the Review of Scientific Instruments that he wrote as a Brown University DOE Science Undergraduate Laboratory Intern (SULI) at PPPL.

Key to predicting the impact of RF waves is measuring the fluctuations, or swings, they create in the density of fusion plasmas. “Once we have those fluctuations we would be able to work backwards to see what those RF fields were that created the fluctuations,” Rutherford said.

However, the high frequency of RF waves causes the swings to occur too rapidly to measure. So the researchers created a “beat wave” by launching two waves at different frequencies, a technique that produced measurable swings. “If we were able to both create a beat wave fluctuation and measure it, we would have a new tool for validating predictions for RF heating and current drive,” Rutherford explained.

Such measurements would have wide-ranging benefits. For example, they could facilitate study of the performance of RF wave actuators, said PPPL physicist Nicola Bertelli, a co-author of the paper, and could enable validation of RF calculation tools developed throughout the fusion community. Moreover, said David Smith, a University of Wisconsin physicist and co-author of the paper, “Our calculations provide an initial assessment of the technique and motivate follow-up experiments on NSTX-U.”

Fusion reactions combine light elements in the form of plasma —  the hot, charged state of matter composed of free electrons and atomic nuclei that makes up 99 percent of the visible universe — to generate massive amounts of energy. Reproducing and controlling this process on Earth would create a virtually inexhaustible supply of safe and clean power to generate electricity. Fusion could become a major contributor to the U.S. transition from fossil fuels to a low-carbon source of electrical generation.

Testing the technique

Rutherford and co-authors tested their technique by creating a synthetic version of a 2D beam emission spectroscopy (BES) diagnostic to evaluate simulated RF injections into the plasma. Their aim was to understand and improve the ability to measure the RF field waves that create the swings. 

Going forward, “We’re hoping that by increasing our ability to measure, we will increase our ability to understand heating and current drive processes, but we’re leaving that to future work,” Rutherford said. Such work could also show whether the BES diagnostic the scientists based their model on could measure the density swings in actual fusion plasmas, or whether some other diagnostic would do the critical job better. 

The DOE Office of Science (FES) supported this work.

PPPL, on Princeton University’s Forrestal Campus in Plainsboro, N.J., is devoted to creating new knowledge about the physics of plasmas — ultra-hot, charged gases — and to developing practical solutions for the creation of fusion energy. The Laboratory is managed by the University for the U.S. Department of Energy’s Office of Science, which is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, visit energy.gov/science.

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A Grand Meteor Shower – Wawa-news.com – Wawa-news.com

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photo courtesy – Pierre Martin

Over the past few weeks, you have probably noticed a few meteors or “shoot stars” at night. You are witnessing one of the best meteor showers of the year. The Perseid Meteor Shower is now underway from July 14 to August 14. The best time to see the most meteors will be on the night of August 12 and into the morning hours of the 13. This year the crescent moon sets around 10:30 p.m. local time leaving us with a dark sky. By contrast, next year’s Perseids takes place under a full moon, drastically reducing the hourly rate.

If you have the chance to observe from dark skies absent of any stray lights, enjoy the band of our Milky Way Galaxy as this collective glow of billions of distant stars stretches from Sagittarius in the south to Cassiopeia in the northeast. Also, brilliant planets Jupiter and Saturn to Jupiter’s right will be out all night long to keep you company. There are unmistakable and located to the left of Sagittarius.

The peak of the Perseids produces about 90 meteors per hour but occurs late afternoon in daylight on the 12th. Towards the end of the night when the constellation Perseus is high in the sky around 3 a.m. we should still see from 50 to 60 meteors striking the atmosphere at 59 km/sec or 36 mi/sec. A higher number of bright fireballs may be seen on nights before the peak rather than nights after. The friction of comet debris causes the “flash” or “streak” which safely vaporize about 80 km high in the atmosphere with no chance of meteorites hitting the ground.

The parent comet is named Swift-Tuttle, a 26 km or 16 mi wide mountain of ice, dust and gravel that last appeared in 1992 in its 133-year orbit around the sun. It will return in the year 2125, replenishing a fresh path of comet debris ejected from the comet’s surface as it gets close to the sun. Here is where the solar radiation interacts with the comet, causing volatile material to vaporize and create the comet’s coma or cometary fog measuring close to 100,000 kilometres wide around the smaller nucleus. A dust tail forms as debris is blown off the comet’s surface much like confetti blowing off the back of a truck on the highway. As Swift-Tuttle retreated from the sun’s warming effects and back to the outer solar system, it faded away becoming a dark mountain once again only to be awakened by the sun upon its return.

The new comet dust lingers in space until Earth plows through the debris field in its yearly orbit around the sun, much like crossing the finish line of a race. This is why the Perseids and other known meteor showers occur at the same time each year. So gather a few friends and/or family members, set up chairs, bring snacks and take advantage of warm moonless conditions to view this epic display. Look up at the stars, listen to the crickets and frogs and let nature bring a sense of calm over you.

Known as “The Backyard Astronomer”, Gary Boyle is an astronomy educator, guest speaker and monthly columnist for the Royal Astronomical Society of Canada. He has been interviewed on more than 50 Canadian radio stations and local Ottawa TV. In recognition of his public outreach in astronomy, the International Astronomical Union has honoured him with the naming of Asteroid (22406) Garyboyle. Follow him on Twitter: @astroeducator or his website: www.wondersofastronomy.com

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NASA, Boeing launch Starliner to the ISS: How to watch test flight live – CNET

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Boeing CST-100 Starliner spacecraft sits atop a ULA Atlas V rocket in July 2021.


Boeing/John Grant

Boeing is set to relaunch its Starliner crew capsule for a second attempt at docking with the International Space Station this Tuesday, Aug. 3 (there won’t be any humans aboard). Boeing’s first try in late 2019 failed to reach the ISS but landed safely back on Earth. 

The mission was originally scheduled to take off Friday, but it’s now aiming for Tuesday after an unexpected issue last Thursday with an ISS module firing its thrusters shortly after docking with the station. 

“The International Space Station team will use the time to continue working checkouts of the newly arrived Roscosmos Nauka multipurpose laboratory module (MLM) and to ensure the station will be ready for Starliner’s arrival,” said NASA in a statement.

Software defects and a communications link problem led to a premature end to the original Boeing test flight in 2019, though the CST-100 Starliner capsule landed safely back on Earth. The upcoming Orbital Flight Test-2 (OFT-2) mission is a chance for Boeing to thoroughly vet its hardware and software before a crew of three American astronauts flies on Starliner.

Both Boeing and SpaceX are part of NASA’s Commercial Crew Program, which is all about sending astronauts to the ISS from American soil. SpaceX has now delivered 10 astronauts to the ISS, and Boeing would like to catch up. First, it’ll need to show that its Starliner can safely reach the ISS and return to Earth.

NASA will livestream the launch, which is scheduled to occur at 10:20 a.m. PT (1:20 p.m. ET) on Tuesday Aug. 3. Coverage is expected to begin at 9:30 a.m. PT. 

Starliner will lift off on a United Launch Alliance (ULA) Atlas V rocket. The capsule will be packed with around 400 pounds of crew supplies and cargo. If all goes well, it’ll dock with the space station about 24 hours later, on Wednesday Aug. 4. Docking will also be covered live by NASA’s NASA TV.

ULA shared some scenic photos from the launch site on Monday as it prepares for liftoff. 

Starliner will spend between five and 10 days at the ISS before bringing research samples back to Earth. Boeing will aim to bring the spacecraft back for a gentle parachute landing in the desert of New Mexico.

“OFT-2 will provide valuable data that will help NASA certify Boeing’s crew transportation system to carry astronauts to and from the space station,” NASA said in a statement July 22 after successfully concluding a flight readiness review.

The mission is a key step for NASA’s plans to run regular crewed launches from the US, ending its reliance on Russian Soyuz spacecraft. If all goes well, the first crewed mission, Boe-CFT, could launch in the next six months.

Follow CNET’s 2021 Space Calendar to stay up to date with all the latest space news this year. You can even add it to your own Google Calendar.    

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Meteor Shower 2021: Why There Are Only A Few Precious Hours In 2021 When You Can Reliably See ‘Shooting Stars’ – Forbes

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Have you ever seen a “shooting star?” If you haven’t, you’ll no doubt have read articles imploring you to go outside and experience a “shower” of meteors. 

There’s no such thing as a “meteor shower.” 

Meteoroids don’t behave like that. “Shooting stars” are caused by Earth’s atmosphere colliding with clumps of dust left along its orbital path by a passing comet. They look like streaks and they last around a second, depending on the “shower” in question.

“Shooting stars” are sudden events that can happen anywhere in the night sky, but they’re sporadic. They rarely happen together. For instance, you might see one out of the corner of your eye and, five minutes later, see another one in a completely different part of the sky. Many of them you will miss. There are never two or three—or more—“raining down” at the same time, as composite photographs would suggest.

Besides, when you read that a “meteor shower” like the Lyrids, Orionids or Geminids could have “up to 150 shooting stars per hour,” what it really means that it might be possible to see that many (the so-called zenithal hourly rate or ZHR) in perfect conditions. That scenario is, in practice, impossible to achieve—you would need to be observing the entire night sky constantly, for many hours either side of the absolute “peak” of activity, and in super-dark skies. 

However, the biggest factor that determines what you’re likely to see—and one many meteor shower-promoters fail to point out—is the effect of Moon and moonlight.

If there’s a first quarter Moon or anything brighter, particularly a full Moon, in the sky during the peak night(s) of a meteor shower, you can forget seeing anything other than the very brightest of “shooting stars.” And they’re very rare. 

If the Moon is big and bright then, in effect, you’ll be observing from under a heavily light-polluted night sky even if you’ve gone to a dark sky destination. 

So which meteor showers are the ones to go for in 2021? There are going to be three meteor showers in 2021 that will occur under near-ideal conditions. 

The bad news?

The first (and by far the best) one isn’t until August 2021.

The good news?

It’s the Perseids, arguably the most famous and easiest meteor shower to observe in the northern hemisphere … largely because it occurs in the middle of summer when it’s easiest to be outdoors at night. 

The best three meteor showers in 2021, these will be best observed after midnight, with the exception of the Draconids, which can be observed right after dark. 

1. Perseid meteor shower 2021

When: Thursday/Friday, August 12/13, 2021

Moon phase: 23%-lit crescent Moon

ZHR: 110

2. Draconid meteor shower 2021

When: Friday/Saturday, October 8/9, 2021

Moon phase: 10%-lit crescent Moon

ZHR: 10

3. South Taurid meteor shower 2021

When: Thursday/Friday, November 4/5, 2021

Moon phase: 0.1%-lit crescent Moon

ZHR: 10

Wishing you clear skies and wide eyes.

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