8 research outputs found
On the use of dielectric elements in axion searches with microwave resonant cavities
This study explores the primary effects of dielectric materials in a resonant
cavity-based search for axion dark matter. While dielectrics prove beneficial
in numerous cases, their incorporation may lead to less-than-optimal
performance, especially for the lowest TM mode. Additionally, the stronger
confinement of the electric field inside the dielectrics can exacerbate mode
mixings, in particular for higher-order modes. Case studies have been carried
out using a combination of analytical solutions and numerical simulations. The
findings indicate dielectric cavities employing the mode
experience a significant reduction in sensitivity when compared to a similar
search conducted in a cavity at equivalent frequency using no dielectrics.Comment: 10 pages, 7 figure
Rydberg-atom-based single-photon detection for haloscope axion searches
We propose a Rydberg-atom-based single-photon detector for signal readout in
dark matter haloscope experiments between 40 eV and 200 eV (10
GHz and 50 GHz). At these frequencies, standard haloscope readout using linear
amplifiers is limited by quantum measurement noise, which can be avoided by
using a single-photon detector. Our single-photon detection scheme can offer
scan rate enhancements up to a factor of over traditional linear
amplifier readout, and is compatible with many different haloscope cavities. We
identify multiple haloscope designs that could use our Rydberg-atom-based
single-photon detector to search for QCD axions with masses above 40 eV
(10 GHz), currently a minimally explored parameter space.Comment: 15 pages, 8 figure
New Results from HAYSTAC's Phase II Operation with a Squeezed State Receiver
A search for dark matter axions with masses has been
performed using the HAYSTAC experiment's squeezed state receiver to achieve
sub-quantum limited noise. This report includes details of the design and
operation of the experiment previously used to search for axions in the mass
ranges and (GHz) and
GHz) as well as upgrades to facilitate an extended search at
higher masses. These upgrades include improvements to the data acquisition
routine which have reduced the effective dead time by a factor of 5, allowing
for the new region to be scanned 1.6 times faster with comparable
sensitivity. No statistically significant evidence of an axion signal is found
in the range (GHz), leading to an
aggregate upper limit exclusion at the level on the axion-photon
coupling of .Comment: 20 pages, 16 figure
Whole-Genome Analysis of <i>Starmerella bacillaris</i> CC-PT4 against MRSA, a Non-<i>Saccharomyces</i> Yeast Isolated from Grape
Starmerella bacillaris is often isolated from environments associated with grape and winemaking. S. bacillaris has many beneficial properties, including the ability to improve the flavor of wine, the production of beneficial metabolites, and the ability to biocontrol. S. bacillaris CC-PT4 (CGMCC No. 23573) was isolated from grape and can inhibit methicillin-resistant Staphylococcus aureus and adaptability to harsh environments. In this paper, the whole genome of S. bacillaris CC-PT4 was sequenced and bioinformatics analyses were performed. The S. bacillaris CC-PT4 genome was finally assembled into five scaffolds with a genome size of 9.45 Mb and a GC content of 39.5%. It was predicted that the strain contained 4150 protein-coding genes, of which two genes encoded killer toxin and one gene encoded lysostaphin. It also contains genes encoding F1F0-ATPases, Na(+)/H(+) antiporter, cation/H(+) antiporter, ATP-dependent bile acid permease, major facilitator superfamily (MFS) antiporters, and stress response protein, which help S. bacillaris CC-PT4 adapt to bile, acid, and other stressful environments. Proteins related to flocculation and adhesion have also been identified in the S. bacillaris CC-PT4 genome. Predicted by antiSMASH, two secondary metabolite biosynthesis gene clusters were found, and the synthesized metabolites may have antimicrobial effects. Furthermore, S. bacillaris CC-PT4 carried genes associated with pathogenicity and drug resistance. Overall, the whole genome sequencing and analysis of S. bacillaris CC-PT4 in this study provide valuable information for understanding the biological characteristics and further development of this strain
An Adaptive Identification Method for Potential Landslide Hazards Based on Multisource Data
The effectiveness of landslide disaster prevention depends largely on the quality of early identification of potential hazards, and how to comprehensively, deeply, and accurately identify such hazards has become a major difficulty in landslide disaster management. Existing deep learning methods for potential landslide hazard identification often use fixed-size window modeling and ignore the different window sizes required by landslides of different scales. To address this problem, we propose an adaptive identification method for potential landslide hazards based on multisource data. Taking Yongping County, China, as the study area, we create a multisource factor dataset based on the landslide disaster background in terms of topography, geology, human activities, hydrology, and vegetation as the sample for the identification model after processing. Moreover, we combine differential interferometric synthetic aperture radar (D-InSAR) and multitemporal InSAR (MT-InSAR) to process the surface deformation of the study area, and we measure the deformation richness based on the average of the pixel deformation difference within the current window of a pixel point in the image. Therefore, convolutional neural networks (CNNs) with different window sizes are adaptively selected. The results show that the precision of adaptive identification of potential landslide hazards in the study area is 85.30%, the recall is 83.03%, and the F1 score is 84.15%. The recognition rate for potential hazards reaches 80%, which is better than the fixed-window modeling result and proves the effectiveness of the proposed method. This method can help to improve intelligent identification systems for potential landslide hazards, and also contribute to the identification of other potential geological hazards, such as mudslides and collapses
An improved synthetic signal injection routine for the Haloscope At Yale Sensitive To Axion Cold dark matter (HAYSTAC)
Microwave cavity haloscopes are among the most sensitive direct detection
experiments searching for dark matter axions via their coupling to photons.
When the power of the expected microwave signal due to axion-photon conversion
is on the order of ~W, having the ability to validate the detector
response and analysis procedure by injecting realistic synthetic axion signals
becomes helpful. Here we present a method based on frequency hopping spread
spectrum for synthesizing axion signals in a microwave cavity haloscope
experiment. It allows us to generate a narrow and asymmetric shape in frequency
space that mimics an axion's spectral distribution, which is derived from a
Maxwell-Boltzmann distribution. In addition, we show that the synthetic axion's
power can be calibrated with reference to the system noise. Compared to the
synthetic axion injection in HAYSTAC phase I, we demonstrated synthetic signal
injection with a more realistic lineshape and calibrated power
The design of the Ali CMB Polarization Telescope receiver
International audienceAliCPT-1 is the first CMB degree scale polarimeter to be deployed to the Tibetan plateau at 5,250m asl. AliCPT-1 is a 95/150GHz 72cm aperture, two lens refracting telescope cooled down to 4K. Alumina lenses image the CMB on a 636mm wide focal plane. The modularized focal plane consists of dichroic polarization-sensitive Transition-Edge Sensors (TESes). Each module includes 1,704 optically active TESes fabricated on a 6in Silicon wafer. Each TES array is read out with a microwave multiplexing with a multiplexing factor up to 2,000. Such large factor has allowed to consider 10's of thousands of detectors in a practical way, enabling to design a receiver that can operate up to 19 TES arrays for a total of 32,300 TESes. AliCPT-1 leverages the technological advancements of AdvACT and BICEP-3. The cryostat receiver is currently under integration and testing. Here we present the AliCPT-1 receiver, underlying how the optimized design meets the experimental requirements