The intensities of the order of 10 W/cm are required to efficiently generate electron-positron pairs in laser-matter interaction when multiple laser beam collision is employed. To achieve such intense laser fields with the upcoming generation of 10 PW laser beams, focusing to sub-micron spot size is required. In this paper, the possibility of pair production cascade development is studied for the case of a standing wave created by two tightly focused colliding laser pulses. Even though the stronger ponderomotive force expels the seed particles from the interaction volume when a tightly focused laser beam is used, tight focusing allows to achieve cascade pair production due to the higher intensity in the focal spot. Optimizing the target density can compensate the expulsion by the ponderomotive force and lower the threshold power required for cascade pair production. This will in principle allow to produce pairs with 10 PW-class laser facilities which are now under construction and will become accessible soon.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5681631 | PMC |
http://dx.doi.org/10.1038/s41598-017-15747-1 | DOI Listing |
Chaos
January 2025
Research Center for Computer Science and Information Technologies, Macedonian Academy of Sciences and Arts, Bul. Krste Misirkov 2, 1000 Skopje, Macedonia.
We study a pair of independent searchers competing for a target under restarts and find that introduction of restarts tends to enhance the search efficiency of an already efficient searcher. As a result, the difference between the search probabilities of the individual searchers increases when the system is subject to restarts. This result holds true independent of the identity of individual searchers or the specific details of the distribution of restart times.
View Article and Find Full Text PDFJ Agric Food Chem
January 2025
Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, Yunnan Characteristic Plant Extraction Laboratory, Functional Molecules Analysis and Biotransformation Key Laboratory of Universities in Yunnan Province, School of Chemical Science and Technology, Yunnan University, Kunming 650091, People's Republic of China.
One new azaphilone derivative () from in ordinary medium, one new phthalide derivative (), a microbial transformation product of ingredients by , a pair of new austdiol enantiomers (+)- and (-)-, one new epsilon-caprolactone derivative (), and one new ophiobolin-type sesterterpenoid () from the in host medium were reported. The structures were determined by spectroscopic analysis and single-crystal X-ray diffraction. Compounds - could completely inhibit the germination of rice seeds at 50 μg/mL, which is higher than that of the positive control.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Department of Physics, Georgia Southern University, Statesboro, Georgia 30460, United States.
Persistent phosphor has emerged as a promising candidate for information storage due to rapid accessibility and low-energy requirements. However, the low storage capacity has limited its practical application. Herein, we skillfully designed and developed NaGdGeO:Pb,Tb stimulated phosphor by trace doped Sm.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Institute of Organic Chemistry, University of Leipzig, 04103 Leipzig, Germany.
The enantioselective synthesis of 1,4-dicarbonyl compounds continues to pose a significant challenge in organic synthesis, and a catalytic process which generates two adjacent stereogenic centers with full stereochemical control is lacking until now. The 1,4-relationship of the functional groups requires an Umpolung strategy as one of the α-carbonyl positions has to be inverted into an electrophilic center to react with a normal enolate. We report herein the highly enantio- and diastereoselective addition of silyl ketene acetals toward electrophilic 1-azaallyl cations to furnish chiral 4-hydrazonoesters, which are masked 1,4-dicarbonyl compounds.
View Article and Find Full Text PDFOrg Lett
January 2025
Department of Chemistry, University at Albany, State University of New York, Albany, New York 12222, United States.
We present the serendipitous discovery of an unusual dimer formed from anthracene-derived polyarenes. Unlike the typical oxidative coupling of substituted aromatic scaffolds, the reaction yielded a dearomatized enone dimer as the sole product. This dearomatized motif, notably, does not undergo the commonly observed rearomatization, and no biaryl products were detected.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!