World’s first crabbing of a proton beam

CERN – European Organization for Nuclear Research logo.

25 May 2018

Image above: Test bench of the first two prototype crab cavities in the Super Proton Synchrotron (SPS) accelerator. The cryomodule containing the cavities is installed on a mobile table that allows it to be moved into the beam line as needed (Image: M. Brice/CERN).

CERN has successfully tested “crab cavities” to rotate a beam of protons – a world first. The test took place on 23 May using a beam from CERN’s Super Proton Synchrotron (SPS) accelerator and showed that bunches of protons could be tilted using these superconducting transverse radiofrequency cavities. These cavities are a key component of the High-Luminosity Large Hadron Collider (HL-LHC), the future upgrade of the LHC.

The HL-LHC, which will be commissioned after 2025, will increase the luminosity of the LHC by a factor of five to ten. Luminosity is a crucial indicator of a collider’s performance: it gives the number of potential collisions per surface unit over a given period of time. In other words, the higher the luminosity, the higher the number of collisions and the more data the experiments can gather. This will allow researchers to observe rare processes that occur beyond the LHC’s present sensitivity level. Physicists will also be able to perform precise studies of the new particles observed at the LHC, such as the Higgs boson. The newly developed crab cavities will play an important role to increase the luminosity.

In the LHC, the two counter-rotating beams are not a continuous stream of particles but are made up of “bunches” of protons a few centimetres long, each containing billions of protons. These bunches meet at a small angle at each collision point of the experiments. When installed at each side of the ATLAS and CMS experiments, the crab cavities will “tilt” bunches of protons in each beam to maximise their overlap at the collision point. Тhis way every proton in the bunch will be forced to pass through the whole length of the opposite bunch, increasing the probability of collisions and hence more luminosity. After being tilted, the motion of the proton bunches appears to be sideways – just like a crab. Crab cavities were already used in the KEKB collider in Japan for electrons and positrons, but never with protons, which are more massive and at significantly higher energies. “The crab cavities are expected to increase the overall luminosity by 15 to 20%,” explains Rama Calaga, leader of the crab cavity project.

Image above: The first prototype crab cavities being assembled during summer 2017 (Image: Julien Ordan/CERN).

The two first crab cavity prototypes were manufactured at CERN in 2017 in collaboration with Lancaster University and the Science and Technology Facilities Council (STFC) in the United Kingdom, as well as the U.S. LHC Accelerator Research Program (USLARP). The cavities were assembled in a cryostat and tested at CERN. They are made of high-purity niobium superconducting material, operating at 2 kelvins (-271°C), in order to generate very high transverse voltage of 3-4 million volts. The cavities were installed in the SPS accelerator during the last winter technical stop to undergo validation tests with proton beams.

The first beam tests on 23 May lasted for more than 5 hours at a temperature of 4.2 K with a single proton bunch accelerated to 26 GeV and containing between 20 and 80 billion protons, almost the intensity of the LHC bunches. The crab cavities were powered to about 10% of their nominal voltage. The “crabbing” was observed using a special monitor to observe the tilt along the length of the bunch.  “These tests mark the start-up of a unique facility for testing superconducting cavities on a high-current, high-energy proton beam,” explains Lucio Rossi, leader of the HL-LHC project. “The results are impressive and crucial to prove the feasibility of using such cavities for increasing the luminosity in the LHC.”

How to get more collisions at the LHC: crab cavities

Video above: Watch this short video to learn more about how the crab cavities work (Video: Polar Media/CERN).

In the coming months, the cavities will be commissioned to their nominal voltage of 3.4 million volts and will undergo a series of tests to fully validate their operation for the HL-LHC era. A total of 16 such cavities will be installed in the HL-LHC – eight near ATLAS and eight near CMS. 

Note:

CERN, the European Organization for Nuclear Research, is one of the world’s largest and most respected centres for scientific research. Its business is fundamental physics, finding out what the Universe is made of and how it works. At CERN, the world’s largest and most complex scientific instruments are used to study the basic constituents of matter — the fundamental particles. By studying what happens when these particles collide, physicists learn about the laws of Nature.

The instruments used at CERN are particle accelerators and detectors. Accelerators boost beams of particles to high energies before they are made to collide with each other or with stationary targets. Detectors observe and record the results of these collisions.

Founded in 1954, the CERN Laboratory sits astride the Franco–Swiss border near Geneva. It was one of Europe’s first joint ventures and now has 22 Member States.

Related links:

Super Proton Synchrotron (SPS): https://home.cern/about/accelerators/super-proton-synchrotron

High-Luminosity Large Hadron Collider (HL-LHC): https://home.cern/topics/high-luminosity-lhc

Large Hadron Collider (LHC): https://home.cern/topics/large-hadron-collider

ATLAS experiment: https://home.cern/about/experiments/atlas

CMS experiment: https://home.cern/about/experiments/cms

Higgs boson: http://home.web.cern.ch/topics/higgs-boson

For more information about European Organization for Nuclear Research (CERN), Visit: https://home.cern/

Images (mentioned), Video (mentioned), Text, Credits: CERN/Corinne Pralavorio.

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Crew Begins Unloading Cygnus, Works Science Ahead of June Crew Swap

ISS – Expedition 55 Mission patch.

May 25, 2018

The Cygnus resupply ship from Orbital ATK is now open for business and the Expedition 55 crew has begun unloading the 7,400 pounds of cargo it delivered Thursday morning. The orbital residents are also conducting space research and preparing for a crew swap in early June.

There are now four spaceships parked at the International Space Station, the newest one having arrived to resupply the crew early Thursday morning. Astronauts Drew Feustel and Norishige Kanai opened Cygnus’ hatches shortly after it was installed to the Unity module. The cargo carrier will remain attached to the station until July so the astronauts can offload new supplies and repack Cygnus with trash.

NASA astronaut Scott Tingle, who caught Cygnus with the Canadarm2 robotic arm, swapped out gear inside a small life science research facility today called TangoLab-1. Tingle also joined Kanai later in the day transferring frozen biological samples from the Destiny lab module to the Kibo lab module.

Image above: This view taken from inside the Cupola shows the Orbital ATK space freighter moments before it was grappled with the Canadarm2 robotic arm on May 24, 2018. Image Credit: NASA.

The duo also joined Commander Anton Shkaplerov and continued to pack gear and check spacesuits ahead of their return to Earth on June 3 inside the Soyuz MS-07 spaceship. When the three crewmates land in Kazakhstan, about three and a half hours after undocking, the trio will have spent 168 days in space and conducted one spacewalk each.

Three new Expedition 56-57 crew members, waiting to replace the homebound station crew, are counting down to a June 6 launch to space. Astronauts Serena Auñón-Chancellor and Alexander Gerst will take a two-day ride to the space station with cosmonaut Sergey Prokopyev inside the Soyuz MS-09 spacecraft for a six-month mission aboard the orbital laboratory.

Related links:

TangoLab-1: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Facility.html?#id=1660

Orbital ATK: https://www.nasa.gov/orbital

Expedition 55: https://www.nasa.gov/mission_pages/station/expeditions/expedition55/index.html

Commercial Resupply: http://www.nasa.gov/mission_pages/station/structure/launch/index.html

Space Station Research and Technology: https://www.nasa.gov/mission_pages/station/research/index.html

International Space Station (ISS): https://www.nasa.gov/mission_pages/station/main/index.html

Image (mentioned), Text, Credits: NASA/Mark Garcia.

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NASA Tracks Lava from Kilauea Volcano

NASA & NOAA – Suomi NPP Mission patch.

May 25, 2018

Image above: At 10:41 a.m. local time (20:41 Universal Time) on May 14, 2018, the Operational Land Imager (OLI) on Landsat 8 acquired a natural-color image of the volcano. Image Credits: NASA Earth Observatory.

NASA is tracking lava flows from Hawaii Island’s Kilauea volcano as fissures erupt and lava makes its way to the ocean.

Using data from the Visible Infrared Imaging Radiometer, or VIIRS, instrument aboard the NASA-NOAA Suomi NPP satellite, NASA’s Disaster Program has been tracking thermal anomalies, or hot spots, indicative of lava flow. VIIRS is the only instrument from space that can track lava flows through hot spots, making it an important additional source of information for the U.S. Geological Survey as it monitors and informs the public of the ongoing volcanic activity, which has produced everything from earthquakes and giant rock projectiles from eruptions to blankets of ash clouds and volcanic smog, or vog.

Image Credit: NASA.

For example, VIIRS captured the above enhanced nighttime image on May 14, 2018, superimposed with hot spots highlighted in red. Multiple hot spots were observed on this satellite overpass near the southeast tip of Hawaii Island. Kilauea volcano is represented by the hot spot to the west.

Image Credit: NASA.

Zooming in over this area shows that those hot spots were located farther east from Leilani area and were consistent with new fissures observed on the ground.

Image Credit: NASA.

This VIIRS image from May 22, 2018, shows the extension of the hot spots toward the ocean, indicating that lava is moving toward and warming the ocean upon contact.

In addition to VIIRS, NASA provides other information on volcanic activity, including aerosol and sulfur dioxide measurements derived from the Ozone Monitoring Instrument (OMI) aboard NASA’s Aura satellite as well as the Ozone Mapping Profiler Suite aboard NASA-NOAA Suomi NPP satellite, and ground deformation and movement with synthetic aperture radar data.

NASA also organized a field mission with airborne radar to provide accurate digital elevation maps that USGS can use to predict lava path flows. Flown on the G-III research aircraft, the Jet Propulsion Laboratory’s Glacier and Ice Surface Topography Interferometer (GLISTIN) instrument is detecting changes in Kilauea’s topography associated with the new lava flows, with the goal of measuring the erupted volume as a function of time and ultimately the total volume of the event.

Related links:

NASA’s Disaster Program: http://disasters.nasa.gov/

NASA’s Aura satellite: https://aura.gsfc.nasa.gov/

Ozone Monitoring Instrument (OMI): https://aura.gsfc.nasa.gov/omi.html

Ozone Mapping Profiler Suite: https://jointmission.gsfc.nasa.gov/omps.html

NASA-NOAA Suomi NPP satellite: https://www.nasa.gov/mission_pages/NPP/main/index.html

Glacier and Ice Surface Topography Interferometer (GLISTIN): https://www.nasa.gov/feature/help-from-above-nasa-aids-kilauea-disaster-response-1

Images (mentioned), Text, Credits: NASA/sreiny.

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