A RF-driven, Cs-enhanced H(-) ion source feeds the SNS accelerator with a high current (typically >50 mA), ∼1.0 ms pulsed beam at 60 Hz. To achieve the persistent high current beam for several weeks long service cycles, each newly installed ion source undergoes a rigorous conditioning and cesiation processes. Plasma conditioning outgases the system and sputter-cleans the ion conversion surfaces. A cesiation process immediately following the plasma conditioning releases Cs to provide coverage on the ion conversion surfaces. The effectiveness of the ion source conditioning and cesiation is monitored with plasma emission spectroscopy using a high-sensitivity optical spectrometer. Plasma emission spectroscopy is also used to provide a means for diagnosing and confirming a failure of the insulating coating of the ion source RF antenna which is immersed in the plasma. Emissions of composition elements of the antenna coating material, Na emission being the most significant, drastically elevate to signal a failure when it happens. Plasma spectra of the developmental ion source with an AlN (aluminum nitrite) chamber and an external RF antenna are also briefly discussed.
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http://dx.doi.org/10.1063/1.4858055 | DOI Listing |
Nat Commun
January 2025
State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, PR China.
Heterotrophic denitrifiers play crucial roles in global carbon and nitrogen cycling. However, their inability to oxidize sulfide renders them vulnerable to this toxic molecule, which inhibits the key enzymatic reaction responsible for reducing nitrous oxide (NO), thereby raising greenhouse gas emissions. Here, we applied microcosm incubations, community-isotope-corrected DNA stable-isotope probing, and metagenomics to characterize a cohort of heterotrophic denitrifiers in estuarine sediments that thrive by coupling sulfur oxidation with denitrification through chemolithoheterotrophic metabolism.
View Article and Find Full Text PDFWorld J Microbiol Biotechnol
January 2025
Zybio Inc, Chongqing, 400082, China.
Lipase (EC 3.1.1.
View Article and Find Full Text PDFMethods Mol Biol
January 2025
Natural Product Lab, Institute of Biology, Leiden University, Leiden, The Netherlands.
Natural products, particularly plants, remain a vital source of bioactive compounds owing to their unparalleled metabolic diversity across pharmaceuticals, cosmetics, foods, and agriculture. However, this diversity, encompassing not only a multitude of compounds but also their varying chemical and physical properties, presents a challenge in their effective utilization. Targeted analysis of specific metabolites, as well as untargeted approaches covering a wide metabolite range, necessitate optimal extraction solvents tailored to meet diverse requirements.
View Article and Find Full Text PDFAnal Chem
January 2025
Department of Chemistry, Faculty of Science, Masaryk University, Brno 625 00, Czech Republic.
Obtaining high-quality matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) images and the reproducibility of the technique depend strongly on the sample preparation protocol. The most crucial part is the application of the MALDI matrix, which often relies on expensive spraying or sublimation coaters. In this work, we present a new dual-polarity matrix for MALDI mass spectrometry imaging (MSI): Basic Blue 7 (BB7), which belongs to the group of triarylmethane dyes.
View Article and Find Full Text PDFJ Fluoresc
January 2025
Materials Science Lab (1), Physics Department, Faculty of Science, Cairo University, Giza, Egypt.
This study reports the synthesis, characterization, and optical properties of ZnO, ZnCeO, and ZnNdO nanoparticles and their interactions with lead acetate solutions. X-ray diffraction (XRD) confirmed that the nanoparticles were synthesized in a single-phase hexagonal structure, with crystallite sizes of 12.48 nm, 50.
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