(Press-News.org) One of the ways to achieve thermonuclear fusion is through a controlled reaction between two light variants of hydrogen, called deuterium and tritium. Mauro Temporal, from the École Normale Supérieure Cachan, in France, and colleagues have made theoretical calculations indicating how best to improve the ignition stage of fusion reaction. Their approach, described in a paper published in EPJ D, involves increasing the uniformity of irradiation using high-power laser beams on the external shell of a spherical capsule containing a mix of deuterium and tritium.
Reaching uniformity of irradiation matters. Indeed, if it can be achieved, it rapidly heats up the capsule and makes it implode, compressing the fuel inside to very high density. This, in turn, induces the compression and heating of a small amount of fuel in a hot spot, which is a sine qua non for reaching the ignition conditions of thermonuclear fusion to produce large energy quantities.
Temporal and colleagues analyse the possibility of using the UK-based Orion facility's high-power laser beams to study uniformity. Orion has a few nanosecond-long pulse -5 kiloJoules in energy -which cannot achieve ignition, but can help to test ways to produce uniform irradiation from non-uniformly distributed beams: a technique called Polar Direct Drive.
Specifically, the authors use numerical simulations to analyse the uniformity of the illumination of a spherical target both in the case of circular or elliptical laser intensity profiles. Their work also takes into account other potentially disruptive factors. These include beam-to-beam power imbalance, laser-beam pointing error and target positioning error.
They demonstrate that this approach reduces considerably the non-uniformity of the capsule irradiation—by 50 percent and 35 percent, for elliptical and circular intensity profiles respectively.
###
Reference:
M. Temporal, B. Canaud, W.J. Garbett, F. Philippe, and R. Ramis (2013), Polar Direct Drive Illumination Uniformity Provided by the Orion Facility, European Physical Journal D, DOI 10.1140/epjd/e2013-40362-4
For more information visit: http://www.epj.org
The full-text article is available to journalists on request.
Uniformity: The secret of better fusion ignition
Theoretical physicists use simulations to investigate the uniformity of irradiation at the ignition stage of thermonuclear fusion reaction
2013-10-11
ELSE PRESS RELEASES FROM THIS DATE:
Turning vapors into foam-like polymer coatings
2013-10-11
Polymers -- the essential component of plastics -- are found in countless commercial, medical, and industrial products. Polymers that are porous are called foam polymers and are especially useful because they combine light weight with rigid mechanical properties. Now a researcher at the University of Rochester has developed a process to grow highly customizable coatings of foam-like polymers.
The process, developed by Mitchell Anthamatten, a chemical engineer at the University's Hajim School of Engineering and Applied Science, involves growing foam polymers directly from ...
CNIO researchers discover a new regulator of drug detoxication
2013-10-11
Drug abuse and alcohol are some of the most frequent causes of liver damage, particularly in developed countries. Such kind of liver damage can cause irreversible liver failure and even cancer. Researchers from the Spanish National Cancer Research Centre (CNIO) have discovered an important new protective role of the Fra-1 protein, which neutralizes the damage caused by agents, such as the analgesic drug acetaminophen (Paracetamol). This is the first study to reveal a function of Fra-1 in protecting this important organ. The study is published today in the journal Hepatology.
The ...
Badgers ultimately responsible for around half of TB in cattle, study estimates
2013-10-11
Badgers are ultimately responsible for roughly half of tuberculosis (TB) in cattle in areas with high TB prevalence, according to new estimates based on data from a previous badger culling trial.
However, only around six per cent of infected cattle catch TB from badgers, with onward transmission between cattle herds accounting for the remainder, the study suggests.
The findings are published in the journal PLOS Currents: Outbreaks.
The role of badgers in spreading bovine TB has been debated intensely as part of discussions about whether badgers should be culled to control ...
Targeted treatment plus chemotherapy could benefit women with ovarian cancer
2013-10-11
Conventional chemotherapy could further extend life in some women with ovarian cancer when used in tandem with a new type of targeted treatment, a new international study shows.
The research, published in the October issue of the journal Clinical Cancer Research, provides important evidence that PARP inhibitor drugs and chemotherapy can both be effective in the same patients, helping women live longer than they would if treated with chemotherapy alone.
The study, in women with mutations to BRCA genes – which increase the risk that ovarian cancer will relapse after treatment, ...
Packaging stem cells in capsules for heart therapy
2013-10-11
Stem cell therapy for heart disease is happening. Around the world, thousands of heart disease patients have been treated in clinical studies with some form of bone marrow cells or stem cells.
But in many of those studies, the actual impact on heart function was modest or inconsistent. One reason is that most of the cells either don't stay in the heart or die soon after being introduced into the body.
Cardiology researchers at Emory have a solution for this problem. The researchers package stem cells in a capsule made of alginate, a gel-like substance. Once packaged, ...
Oral nutritional supplement use in pediatric inpatients decrease hospital stay and costs
2013-10-11
A new study has found that the use of oral nutritional supplements provided to pediatric patients during hospitalization was associated with a decrease in length of stay of 14.8 percent and a decrease in hospital stay costs of $1,768 per patient. The study, conducted by leading researchers at the University of Southern California, The Children's Hospital of Philadelphia, Harvard Medical School, Massachusetts General Hospital, and Precision Health Economics, and supported by Abbott, is being presented this weekend at the 2013 North American Society for Pediatric Gastroenterology, ...
New approach urged for 'abysmal' K-12 writing instruction
2013-10-11
EAST LANSING, Mich. — Writing instruction in U.S. classrooms is "abysmal" and the Common Core State Standards don't go far enough to address glaring gaps for students and teachers, a Michigan State University education scholar argues.
In a new study, Gary Troia calls for a fresh approach to professional development for teachers who must help students meet the new writing standards. His research, funded by the U.S. Department of Education's Institute of Education Sciences, appears in the journal School Psychology Review.
"We need to re-orient the way we think about teacher ...
Prostate cancer: A change in circulating tumor cells detection has high potential in the prediction
2013-10-11
Arnhem, 11 October 2013- A new study reveals that in the prediction of treatment outcome for castration-resistant prostate cancer, a change in circulating tumour cells detection might be more accurate than the change in prostate-specific antigen levels. The findings of this award-winning study were presented at the recent EAU 13th Central European Meeting in Prague.
"The research of the circulating tumour cells (CTC) is of utmost importance, because nowadays there is no reliable marker of both cancer-specific or overall survival in castration-resistant prostate cancer ...
Innovation in renewable-energy technologies is booming
2013-10-11
CAMBRIDGE, MA -- The number of patents issued for renewable-energy technologies has risen sharply over the last decade, according to new research from MIT and the Santa Fe Institute (SFI). The study shows that investments in research and development, as well as in the growth of markets for these products, have helped to spur this dramatic growth in innovation.
"We were quite surprised," says Jessika Trancik, an assistant professor of engineering systems at MIT and a co-author of the new report, published in the journal PLoS ONE. Trancik -- working with Luís Bettencourt ...
Predators vs. alien: European shrimps win predatory battles with an American invader
2013-10-11
A shrimp from America has been invading Europe's rivers and lakes for several decades, but something seems to be preventing this colonist from becoming numerous and problematic, like so many other invaders - such as the Californian grey squirrel and American crayfish. Could the resident European shrimps have something to do with this?
Jaimie Dick and his colleagues mapped the occurrence of the interloper and found it only existed where native shrimps were absent or rare. When native shrimps were common, the American shrimp simply could not establish and it disappeared. ...
LAST 30 PRESS RELEASES:
Neighborhood factors may lead to increased COPD-related emergency department visits, hospitalizations
Food insecurity impacts employees’ productivity
Prenatal infection increases risk of heavy drinking later in life
‘The munchies’ are real and could benefit those with no appetite
FAU researchers discover novel bacteria in Florida’s stranded pygmy sperm whales
DEGU debuts with better AI predictions and explanations
‘Giant superatoms’ unlock a new toolbox for quantum computers
Jeonbuk National University researchers explore metal oxide electrodes as a new frontier in electrochemical microplastic detection
Cannabis: What is the profile of adults at low risk of dependence?
Medical and materials innovations of two women engineers recognized by Sony and Nature
Blood test “clocks” predict when Alzheimer’s symptoms will start
Second pregnancy uniquely alters the female brain
Study shows low-field MRI is feasible for breast screening
Nanodevice produces continuous electricity from evaporation
Call me invasive: New evidence confirms the status of the giant Asian mantis in Europe
Scientists discover a key mechanism regulating how oxytocin is released in the mouse brain
Public and patient involvement in research is a balancing act of power
Scientists discover “bacterial constipation,” a new disease caused by gut-drying bacteria
DGIST identifies “magic blueprint” for converting carbon dioxide into resources through atom-level catalyst design
COVID-19 vaccination during pregnancy may help prevent preeclampsia
Menopausal hormone therapy not linked to increased risk of death
Chronic shortage of family doctors in England, reveals BMJ analysis
Booster jabs reduce the risks of COVID-19 deaths, study finds
Screening increases survival rate for stage IV breast cancer by 60%
ACC announces inaugural fellow for the Thad and Gerry Waites Rural Cardiovascular Research Fellowship
University of Oklahoma researchers develop durable hybrid materials for faster radiation detection
Medicaid disenrollment spikes at age 19, study finds
Turning agricultural waste into advanced materials: Review highlights how torrefaction could power a sustainable carbon future
New study warns emerging pollutants in livestock and aquaculture waste may threaten ecosystems and public health
Integrated rice–aquatic farming systems may hold the key to smarter nitrogen use and lower agricultural emissions
[Press-News.org] Uniformity: The secret of better fusion ignitionTheoretical physicists use simulations to investigate the uniformity of irradiation at the ignition stage of thermonuclear fusion reaction