From The Laboratory for Laser Energetics (LLE) At The University of Rochester Via The DOE’s Lawrence Livermore National Laboratory: “Novel experimental platform enables first measurements of ion-acoustic wave bursts during magnetic reconnection”
University of Rochester(US) The main amplifiers at the OMEGA EP laser at the University of Rochester’s Laboratory for Laser Energetics.
From The Laboratory for Laser Energetics (LLE)
at
Via
The DOE’s Lawrence Livermore National Laboratory
3.8.23
Patricia Koning
koning3@llnl.gov
(925) 423-4332
A series of experiments conducted at the Omega Laser, part of the University of Rochester’s Laboratory for Laser Energetics, provide new insights into magnetic reconnection, a process that could help explain stellar flares and other astrophysical phenomena. The research confirmed that unstable ion-acoustic waves (IAWs) could be important to further understanding of the dissipation physics during magnetic reconnection.
“Now we are excited by having re-discovered [ion-acoustic waves’] importance under certain conditions which may exist in a wide range of phenomena in space and astrophysics,” said Hantao Ji of the Princeton Plasma Physics Laboratory, one of the paper’s authors.
The results were published in Nature Physics [below] in a paper titled “Ion and Electron Acoustic Bursts during Anti-Parallel Reconnection Driven by Lasers.” A team of researchers from Princeton University led the work, with contributions from the University of Rochester, the Massachusetts Institute of Technology, and Lawrence Livermore National Laboratory (LLNL).
“This is inspiring work. It shows it’s possible to learn exquisite details from a simple experimental setup with extensive data analysis. There is a lot we don’t know about magnetic reconnection, but this work opens some interesting avenues to pursue,” said LLNL physicist John Moody, also an author. He provided insights on the mechanisms of the novel laser-powered capacitor coil currents of the experimental platform and the target design.
Magnetic reconnection is the breaking and reconnecting of non-parallel magnetic field lines in a plasma. In the process, magnetic field energy is converted to plasma kinetic and thermal energy. Magnetic reconnection is believed to power astrophysical phenomena like solar flares and the northern lights.
In the experiments, the researchers created an experimental platform to produce magnetic reconnection similar to that observed in the solar atmosphere. In the platform, two ultraviolet laser beams pass through holes in the first copper plate to reach a second plate and generate electric currents through two parallel loops connecting the plates. The geometry created between the two coils allows improved plasma confinement and efficient particle acceleration. The accelerated electrons then drive the ion-acoustic waves measured in these experiments.
The researchers theorized that a 3D kinetic dissipation mechanism in magnetic reconnection could be caused by unstable IAWs driven by the relative drift between electrons and ions, or equivalently electric current. Using this novel experimental platform, they were able to measure the sudden onset of bursts of IAWs for the first time using collective Thomson scattering diagnostics.
“This gives new insight into the dissipation physics of magnetic reconnection,” said LLNL physicist Hui Chen, also a co-author. She contributed to the project by providing the particle spectrometer and training graduate students on analyzing the particle data.
The research team plans further experiments, including with increased generation of current in the semicircular coils to address questions such as efficiency and universality of IAW to dissipate magnetic energy during reconnection in wider parameter space.
Nature Physics
From the science paper.
Abstract
Magnetic reconnection converts magnetic energy into thermal and kinetic energy in plasma. Among the numerous candidate mechanisms, ion acoustic instabilities driven by the relative drift between ions and electrons (or equivalently, electric current) have been suggested to play a critical role in dissipating magnetic energy in collisionless plasmas. However, their existence and effectiveness during reconnection have not been well understood due to ion Landau damping and difficulties in resolving the Debye length scale in the laboratory. Here we report a sudden onset of ion acoustic bursts measured by collective Thomson scattering in the exhaust of anti-parallel magnetically driven reconnection using high-power lasers. The ion acoustic bursts are followed by electron acoustic bursts with electron heating and bulk acceleration. We reproduce these observations with one- and two-dimensional particle-in-cell simulations in which an electron outflow jet drives ion acoustic instabilities, forming double layers. These layers induce electron two-stream instabilities that generate electron acoustic bursts and energize electrons. Our results demonstrate the importance of ion and electron acoustic dynamics during reconnection when ion Landau damping is ineffective, a condition applicable to a range of astrophysical plasmas including near-Earth space, stellar flares and black hole accretion engines.
For further images see the science paper.
For further images see the science paper.
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The DOE’s Lawrence Livermore National Laboratory (LLNL) is an American federal research facility in Livermore, California, United States, founded by the University of California- Berkeley in 1952. A Federally Funded Research and Development Center (FFRDC), it is primarily funded by The U.S. Department of Energy and managed and operated by Lawrence Livermore National Security, LLC (LLNS), a partnership of the University of California, Bechtel, BWX Technologies, AECOM, and Battelle Memorial Institute in affiliation with the Texas A&M University System. In 2012, the laboratory had the synthetic chemical element livermorium named after it.
LLNL is self-described as “a premier research and development institution for science and technology applied to national security.” Its principal responsibility is ensuring the safety, security and reliability of the nation’s nuclear weapons through the application of advanced science, engineering and technology. The Laboratory also applies its special expertise and multidisciplinary capabilities to preventing the proliferation and use of weapons of mass destruction, bolstering homeland security and solving other nationally important problems, including energy and environmental security, basic science and economic competitiveness.
The National Ignition Facility, is a large laser-based inertial confinement fusion (ICF) research device, located at The DOE’s Lawrence Livermore National Laboratory in Livermore, California. NIF uses lasers to heat and compress a small amount of hydrogen fuel with the goal of inducing nuclear fusion reactions. NIF’s mission is to achieve fusion ignition with high energy gain, and to support nuclear weapon maintenance and design by studying the behavior of matter under the conditions found within nuclear weapons. NIF is the largest and most energetic ICF device built to date, and the largest laser in the world.
Construction on the NIF began in 1997 but management problems and technical delays slowed progress into the early 2000s. Progress after 2000 was smoother, but compared to initial estimates, NIF was completed five years behind schedule and was almost four times more expensive than originally budgeted. Construction was certified complete on 31 March 2009 by the U.S. Department of Energy, and a dedication ceremony took place on 29 May 2009. The first large-scale laser target experiments were performed in June 2009 and the first “integrated ignition experiments” (which tested the laser’s power) were declared completed in October 2010.
Bringing the system to its full potential was a lengthy process that was carried out from 2009 to 2012. During this period a number of experiments were worked into the process under the National Ignition Campaign, with the goal of reaching ignition just after the laser reached full power, sometime in the second half of 2012. The Campaign officially ended in September 2012, at about 1⁄10 the conditions needed for ignition. Experiments since then have pushed this closer to 1⁄3, but considerable theoretical and practical work is required if the system is ever to reach ignition. Since 2012, NIF has been used primarily for materials science and weapons research.
National Igniton Facility- NIF at LLNL
National Ignition Facility located at the DOE’s Lawrence Livermore National Laboratory in Livermore, California.
Operated by Lawrence Livermore National Security, LLC, for the Department of Energy’s National Nuclear Security Administration
The Laboratory for Laser Energetics (LLE)
The Laboratory for Laser Energetics (LLE) is a scientific research facility which is part of the University of Rochester’s south campus, located in Brighton, New York. The lab was established in 1970 and its operations since then have been funded jointly; mainly by the United States Department of Energy, the University of Rochester and the New York State government. The Laser Lab was commissioned to serve as a center for investigations of high-energy physics, specifically those involving the interaction of extremely intense laser radiation with matter. Many types of scientific experiments are performed at the facility with a strong emphasis on inertial confinement, direct drive, laser-induced fusion, fundamental plasma physics and astrophysics using OMEGA. In June 1995, OMEGA became the world’s highest-energy ultraviolet laser. The lab shares its building with the Center for Optoelectronics and Imaging and the Center for Optics Manufacturing. The Robert L. Sproull Center for Ultra High Intensity Laser Research was opened in 2005 and houses the OMEGA EP laser, which was completed in May 2008.
The laboratory is unique in conducting big science on a university campus. More than 180 Ph.D.s have been awarded for research done at the LLE. During summer months the lab sponsors a program for high school students which involves local-area high school juniors in the research being done at the laboratory. Most of the projects are done on current research that is led by senior scientists at the lab.
The LLE was founded on the University of Rochester’s campus in 1970, by Dr. Moshe Lubin. Working with outside companies such as Kodak the team built Delta, a four beam laser system in 1972. Construction started on the current LLE site in 1976. The facility opened a six beam laser system in 1978 and followed with a 24 beam system two years later. In 2018, Donna Strickland and Gérard Mourou shared a Nobel prize for work they had undertaken in 1985 while at LLE. They invented a method to amplify laser pulses by “chirping” for which they would share the 2018 Nobel Prize in Physics. This method disperses a short, broadband pulse of laser light into a temporally longer spectrum of wavelengths. The system amplifies the laser at each wavelength and then reconstitutes the beam into one color. Chirp pulsed amplification became instrumental in building the National Ignition Facility at the DOE’s Lawrence Livermore National Laboratory and the Omega EP system. In 1995, the omega laser system was increased to 60 beams, and in 2008 the Omega extended performance system was opened.
The Guardian and Scientific American provided simplified summaries of the work of Strickland and Mourou: it “paved the way for the shortest, most intense laser beams ever created”. “The ultrabrief, ultrasharp beams can be used to make extremely precise cuts so their technique is now used in laser machining and enables doctors to perform millions of corrective” laser eye surgeries.
University of Rochester campus
The University of Rochester is a private research university in Rochester, New York. The university grants undergraduate and graduate degrees, including doctoral and professional degrees.
The University of Rochester enrolls approximately 6,800 undergraduates and 5,000 graduate students. Its 158 buildings house over 200 academic majors. According to the National Science Foundation, Rochester spent $370 million on research and development in 2018, ranking it 68th in the nation. The university is the 7th largest employer in the Finger lakes region of New York.
The College of Arts, Sciences, and Engineering is home to departments and divisions of note. The Institute of Optics was founded in 1929 through a grant from Eastman Kodak and Bausch and Lomb as the first educational program in the US devoted exclusively to optics and awards approximately half of all optics degrees nationwide and is widely regarded as the premier optics program in the nation and among the best in the world.
The Departments of Political Science and Economics have made a significant and consistent impact on positivist social science since the 1960s and historically rank in the top 5 in their fields. The Department of Chemistry is noted for its contributions to synthetic organic chemistry, including the first lab based synthesis of morphine. The Rossell Hope Robbins Library serves as the university’s resource for Old and Middle English texts and expertise. The university is also home to Rochester’s Laboratory for Laser Energetics, a Department of Energy supported national laboratory.
University of Rochester Laboratory for Laser Energetics.
The University of Rochester’s Eastman School of Music ranks first among undergraduate music schools in the U.S. The Sibley Music Library at Eastman is the largest academic music library in North America and holds the third largest collection in the United States.
In its history university alumni and faculty have earned 13 Nobel Prizes; 13 Pulitzer Prizes; 45 Grammy Awards; 20 Guggenheim Awards; 5 National Academy of Sciences; 4 National Academy of Engineering; 3 Rhodes Scholarships; 3 National Academy of Inventors; and 1 National Academy of Inventors Hall of Fame.
History
Early history
The University of Rochester traces its origins to The First Baptist Church of Hamilton (New York) which was founded in 1796. The church established the Baptist Education Society of the State of New York later renamed the Hamilton Literary and Theological Institution in 1817. This institution gave birth to both Colgate University and the University of Rochester. Its function was to train clergy in the Baptist tradition. When it aspired to grant higher degrees it created a collegiate division separate from the theological division.
The collegiate division was granted a charter by the State of New York in 1846 after which its name was changed to Madison University. John Wilder and the Baptist Education Society urged that the new university be moved to Rochester, New York. However, legal action prevented the move. In response, dissenting faculty, students, and trustees defected and departed for Rochester, where they sought a new charter for a new university.
Madison University was eventually renamed as Colgate University.
Founding
Asahel C. Kendrick- professor of Greek- was among the faculty that departed Madison University for Rochester. Kendrick served as acting president while a national search was conducted. He reprised this role until 1853 when Martin Brewer Anderson of the Newton Theological Seminary in Massachusetts was selected to fill the inaugural posting.
The University of Rochester’s new charter was awarded by the Regents of the State of New York on January 31, 1850. The charter stipulated that the university have $100,000 in endowment within five years upon which the charter would be reaffirmed. An initial gift of $10,000 was pledged by John Wilder which helped catalyze significant gifts from individuals and institutions.
Classes began that November with approximately 60 students enrolled including 28 transfers from Madison. From 1850 to 1862 the university was housed in the old United States Hotel in downtown Rochester on Buffalo Street near Elizabeth Street- today West Main Street near the I-490 overpass. On a February 1851 visit Ralph Waldo Emerson said of the university:
“They had bought a hotel, once a railroad terminus depot, for $8,500, turned the dining room into a chapel by putting up a pulpit on one side, made the barroom into a Pythologian Society’s Hall, & the chambers into Recitation rooms, Libraries, & professors’ apartments, all for $700 a year. They had brought an omnibus load of professors down from Madison bag and baggage… called in a painter and sent him up the ladder to paint the title “University of Rochester” on the wall, and they had runners on the road to catch students. And they are confident of graduating a class of ten by the time green peas are ripe.”
For the next 10 years the college expanded its scope and secured its future through an expanding endowment; student body; and faculty. In parallel a gift of 8 acres of farmland from local businessman and Congressman Azariah Boody secured the first campus of the university upon which Anderson Hall was constructed and dedicated in 1862. Over the next sixty years this Prince Street Campus grew by a further 17 acres and was developed to include fraternities’ houses; dormitories; and academic buildings including Anderson Hall; Sibley Library; Eastman and Carnegie Laboratories the Memorial Art Gallery and Cutler Union.
Twentieth century
Coeducation
The first female students were admitted in 1900- the result of an effort led by Susan B. Anthony and Helen Barrett Montgomery. During the 1890s a number of women took classes and labs at the university as “visitors” but were not officially enrolled nor were their records included in the college register. President David Jayne Hill allowed the first woman- Helen E. Wilkinson- to enroll as a normal student although she was not allowed to matriculate or to pursue a degree. Thirty-three women enrolled among the first class in 1900 and Ella S. Wilcoxen was the first to receive a degree in 1901. The first female member of the faculty was Elizabeth Denio who retired as Professor Emeritus in 1917. Male students moved to River Campus upon its completion in 1930 while the female students remained on the Prince Street campus until 1955.
Expansion
Major growth occurred under the leadership of Benjamin Rush Rhees over his 1900-1935 tenure. During this period George Eastman became a major donor giving more than $50 million to the university during his life. Under the patronage of Eastman, the Eastman School of Music was created in 1921. In 1925 at the behest of the General Education Board and with significant support for John D. Rockefeller George Eastman and Henry A. Strong’s family medical and dental schools were created. The university award its first Ph.D that same year.
During World War II University of Rochester was one of 131 colleges and universities nationally that took part in the V-12 Navy College Training Program which offered students a path to a Navy commission. In 1942, the university was invited to join the Association of American Universities as an affiliate member and it was made a full member by 1944. Between 1946 and 1947 in infamous uranium experiments researchers at the university injected uranium-234 and uranium-235 into six people to study how much uranium their kidneys could tolerate before becoming damaged.
In 1955 the separate colleges for men and women were merged into The College on the River Campus. In 1958 three new schools were created in engineering; business administration and education. The Graduate School of Management was named after William E. Simon- former Secretary of the Treasury in 1986. He committed significant funds to the school because of his belief in the school’s free market philosophy and grounding in economic analysis.
Financial decline and name change controversy
Following the princely gifts given throughout his life George Eastman left the entirety of his estate to the university after his death by suicide. The total of these gifts surpassed $100 million before inflation and as such Rochester enjoyed a privileged position amongst the most well endowed universities. During the expansion years between 1936 and 1976 the University of Rochester’s financial position ranked third, near Harvard University’s endowment and the University of Texas System’s Permanent University Fund. Due to a decline in the value of large investments and a lack of portfolio diversity the university’s place dropped to the top 25 by the end of the 1980s. At the same time the preeminence of the city of Rochester’s major employers began to decline.
In response the University commissioned a study to determine if the name of the institution should be changed to “Eastman University” or “Eastman Rochester University”. The study concluded a name change could be beneficial because the use of a place name in the title led respondents to incorrectly believe it was a public university, and because the name “Rochester” connoted a “cold and distant outpost.” Reports of the latter conclusion led to controversy and criticism in the Rochester community. Ultimately, the name “University of Rochester” was retained.
Renaissance Plan
In 1995 University of Rochester president Thomas H. Jackson announced the launch of a “Renaissance Plan” for The College that reduced enrollment from 4,500 to 3,600 creating a more selective admissions process. The plan also revised the undergraduate curriculum significantly creating the current system with only one required course and only a few distribution requirements known as clusters. Part of this plan called for the end of graduate doctoral studies in chemical engineering; comparative literature; linguistics; and mathematics the last of which was met by national outcry. The plan was largely scrapped and mathematics exists as a graduate course of study to this day.
Twenty-first century
Meliora Challenge
Shortly after taking office university president Joel Seligman commenced the private phase of the “Meliora Challenge”- a $1.2 billion capital campaign- in 2005. The campaign reached its goal in 2015- a year before the campaign was slated to conclude. In 2016, the university announced the Meliora Challenge had exceeded its goal and surpassed $1.36 billion. These funds were allocated to support over 100 new endowed faculty positions and nearly 400 new scholarships.
The Mangelsdorf Years
On December 17, 2018 the University of Rochester announced that Sarah C. Mangelsdorf would succeed Richard Feldman as President of the University. Her term started in July 2019 with a formal inauguration following in October during Meliora Weekend. Mangelsdorf is the first woman to serve as President of the University and the first person with a degree in psychology to be appointed to Rochester’s highest office.
In 2019 students from China mobilized by the Chinese Students and Scholars Association (CSSA) defaced murals in the University’s access tunnels which had expressed support for the 2019 Hong Kong Protests, condemned the oppression of the Uighurs, and advocated for Taiwanese independence. The act was widely seen as a continuation of overseas censorship of Chinese issues. In response a large group of students recreated the original murals. There have also been calls for Chinese government run CSSA to be banned from campus.
Research
Rochester is a member of the Association of American Universities and is classified among “R1: Doctoral Universities – Very High Research Activity”.
Rochester had a research expenditure of $370 million in 2018.
In 2008 Rochester ranked 44th nationally in research spending but this ranking has declined gradually to 68 in 2018.
Some of the major research centers include the Laboratory for Laser Energetics, a laser-based nuclear fusion facility, and the extensive research facilities at the University of Rochester Medical Center.
Recently the university has also engaged in a series of new initiatives to expand its programs in biomedical engineering and optics including the construction of the new $37 million Robert B. Goergen Hall for Biomedical Engineering and Optics on the River Campus.
Other new research initiatives include a cancer stem cell program and a Clinical and Translational Sciences Institute. UR also has the ninth highest technology revenue among U.S. higher education institutions with $46 million being paid for commercial rights to university technology and research in 2009. Notable patents include Zoloft and Gardasil. WeBWorK, a web-based system for checking homework and providing immediate feedback for students was developed by University of Rochester professors Gage and Pizer. The system is now in use at over 800 universities and colleges as well as several secondary and primary schools. Rochester scientists work in diverse areas. For example, physicists developed a technique for etching metal surfaces such as platinum; titanium; and brass with powerful lasers enabling self-cleaning surfaces that repel water droplets and will not rust if tilted at a 4 degree angle; and medical researchers are exploring how brains rid themselves of toxic waste during sleep.
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