scholarly journals Development and Vertical Tests of CEPC 650-MHz Single-Cell Cavities with High Gradient

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7654
Author(s):  
Song Jin ◽  
Peng Sha ◽  
Weimin Pan ◽  
Jiyuan Zhai ◽  
Zhenghui Mi ◽  
...  
Keyword(s):  
Single Cell ◽  
Quality Factor ◽  
State Of The Art ◽  
Test Results ◽  
Fine Grain ◽  
Electron Positron ◽  
Superconducting Cavities ◽  
Intrinsic Quality ◽  
Quality Factor Q ◽  
Vertical Test

A circular electron positron collider (CEPC) will adopt hundreds of 650-MHz superconducting cavities with high quality factor (Q) and accelerating gradient (Eacc). Two 650-MHz single-cell cavities made of fine-grain niobium were first treated via buffered chemical polishing (BCP), which was easy and convenient. However, the vertical test results could not meet the specification of the CEPC (4 × 1010 at 22 MV/m). Therefore, electro-polishing (EP) of 650-MHz single-cell cavities was conducted, which was complicated but remarkably effective. Both 650-MHz single-cell cavities achieved state-of-the-art gradients of 35 MV/m after the EP process, which is extremely high for large elliptical cavities (frequency < 1 GHz). One cavity achieved an intrinsic quality factor (Q0) of 4.5 × 1010 at 22.0 MV/m, which was higher than the CEPC spec. The other cavity obtained a lower Q0 of 3.4 × 1010 at 22.0 MV/m, which may have resulted from the cancellation of high-temperature annealing.

scholarly journals 422 Million intrinsic quality factor planar integrated all-waveguide resonator with sub-MHz linewidth

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Matthew W. Puckett ◽  
Kaikai Liu ◽  
Nitesh Chauhan ◽  
Qiancheng Zhao ◽  
Naijun Jin ◽  
...  
Keyword(s):  
Quality Factor ◽  
High Capacity ◽  
Precision Spectroscopy ◽  
Narrow Linewidth ◽  
Waveguide Resonator ◽  
Environmental Disturbances ◽  
Fiber Communications ◽  
Intrinsic Quality ◽  
Quality Factor Q ◽  
Quantum Photonics

AbstractHigh quality-factor (Q) optical resonators are a key component for ultra-narrow linewidth lasers, frequency stabilization, precision spectroscopy and quantum applications. Integration in a photonic waveguide platform is key to reducing cost, size, power and sensitivity to environmental disturbances. However, to date, the Q of all-waveguide resonators has been relegated to below 260 Million. Here, we report a Si3N4 resonator with 422 Million intrinsic and 3.4 Billion absorption-limited Qs. The resonator has 453 kHz intrinsic, 906 kHz loaded, and 57 kHz absorption-limited linewidths and the corresponding 0.060 dB m−1 loss is the lowest reported to date for waveguides with deposited oxide upper cladding. These results are achieved through a careful reduction of scattering and absorption losses that we simulate, quantify and correlate to measurements. This advancement in waveguide resonator technology paves the way to all-waveguide Billion Q cavities for applications including nonlinear optics, atomic clocks, quantum photonics and high-capacity fiber communications.

scholarly journals Quality Factor Enhancement of 650 MHz Superconducting Radio-Frequency Cavity for CEPC

2022 ◽  
Vol 12 (2) ◽  
pp. 546
Author(s):  
Peng Sha ◽  
Weimin Pan ◽  
Jiyuan Zhai ◽  
Zhenghui Mi ◽  
Song Jin ◽  
...  
Keyword(s):  
Radio Frequency ◽  
Quality Factor ◽  
Microwave Surface Resistance ◽  
Medium Temperature ◽  
Residual Resistance ◽  
Electron Positron ◽  
Superconducting Radio Frequency ◽  
Unloaded Quality Factor ◽  
Srf Cavity ◽  
Vertical Test

Medium-temperature (mid-T) furnace baking was conducted at 650 MHz superconducting radio-frequency (SRF) cavity for circular electron positron collider (CEPC), which enhanced the cavity unloaded quality factor (Q0) significantly. In the vertical test (2.0 K), Q0 of 650 MHz cavity reached 6.4 × 1010 at 30 MV/m, which is remarkably high at this unexplored frequency. Additionally, the cavity quenched at 31.2 MV/m finally. There was no anti-Q-slope behavior after mid-T furnace baking, which is characteristic of 1.3 GHz cavities. The microwave surface resistance (RS) was also studied, which indicated both very low Bardeen–Cooper–Schrieffer (BCS) and residual resistance. The recipe of cavity process in this paper is simplified and easy to duplicate, which may benefit the SRF community.

NÉEL LINES STRUCTURES IN UNIAXIAL FERROMAGNETS WITH QUALITY FACTOR Q > 1

1988 ◽  
Vol 49 (C8) ◽  
pp. C8-1947-C8-1948
Author(s):  
J. Miltat ◽  
P. Trouilloud
Keyword(s):  
Quality Factor ◽  
Quality Factor Q

Experiences in Field Testing a Variety of Aeration Equipment in Sweden and in the U.S.A. by Offgas Analysis

1989 ◽  
Vol 21 (10-11) ◽  
pp. 1421-1429
Author(s):  
D. T. Redmon ◽  
W. C. Boyle ◽  
B. G. Hellstrom
Keyword(s):  
Oxygen Transfer ◽  
State Of The Art ◽  
Field Testing ◽  
Analysis Procedure ◽  
Test Results ◽  
Transfer Testing ◽  
Parallel Tests

The background and theory of the offgas analysis procedure used in oxygen transfer testing of diffused aeration tanks is reviewed. Correlation of this method with other applicable procedures in parallel tests is reported. State-of-the-art equipment and accessories are described. Advantages of the procedure are identified, as are precautionary considerations regarding its use. Applications considered appropriate for its employment are delineated. Experience and test results in both Sweden and the U.S.A. on a variety of aeration devices are disclosed.

scholarly journals Global optimization of an encapsulated Si/SiO$$_2$$ L3 cavity with a 43 million quality factor

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
J. P. Vasco ◽  
V. Savona
Keyword(s):  
Global Optimization ◽  
Photonic Crystal ◽  
Quality Factor ◽  
State Of The Art ◽  
Optimization Strategy ◽  
High Quality ◽  
Optimal Value ◽  
Out Of Plane ◽  
Fabrication Tolerances ◽  
Structural Imperfections

AbstractWe optimize a silica-encapsulated silicon L3 photonic crystal cavity for ultra-high quality factor by means of a global optimization strategy, where the closest holes surrounding the cavity are varied to minimize out-of-plane losses. We find an optimal value of $$Q_c=4.33\times 10^7$$ Q c = 4.33 × 10 7 , which is predicted to be in the 2 million regime in presence of structural imperfections compatible with state-of-the-art silicon fabrication tolerances.

Study of Inductance-Coupling-RFID Tag's Quality Factor

2013 ◽  
Vol 722 ◽  
pp. 198-201
Author(s):  
Cai Feng Liu ◽  
Fu Gui Yan ◽  
Di Feng Lu ◽  
Yang Mei
Keyword(s):  
Quality Factor ◽  
Simulation Analysis ◽  
Influence Factors ◽  
Rfid Tags ◽  
Space Thickness ◽  
Manufacturing Quality ◽  
Length Width ◽  
Quality Factor Q

To improve the read performance of RFID tags,improve the quality factor is very important. Firstly,from theory and practical, confirmed that quality factor Q is very important for RFID tags,a higher Q means the tag could have a good performance. Then,through calculations and simulation,analysis the influence factors of Q. With simulation figures show that length, width, space, thickness of the tags coil all affect the Q,but when manufacturing of tags , the control of manufacturing quality and accuracy is very difficultly. Finally, shows many figures about tags manufacturing quality and accuracy of manufacturing which have lower Q and badly read performance.

scholarly journals A Review on the Performance and Comfort of Stab Protection Armor

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Dereje Berihun Sitotaw ◽  
Dustin Ahrendt ◽  
Yordan Kyosev ◽  
Abera Kechi Kabish
Keyword(s):  
Protective Clothing ◽  
State Of The Art ◽  
Upper Body ◽  
Test Results ◽  
Safety Equipment ◽  
Freedom Of Movement ◽  
Prototype Test ◽  
Wear Comfort ◽  
Correction Officers ◽  
Security Control

Abstract Stab-protective clothing is the most important component of safety equipment and it helps to save the lives of its wearers; therefore, it is designed to resist knife, nail, or needle attacks, especially to the upper body. In this paper, the essential requirements for stab-resistant armor are investigated based on an in-depth review of previous research and prototype test results. The combination of protection and comfort in armor vests is a particularly challenging task. Review of the state of the art technology responsible for the manufacture of stab-resistant clothes has revealed that their design and development should encompass the elements of comfort, freedom of movement, permeability, absorption, evaporation, and weight reductions to ensure excellent ergonomics and high wear comfort. The design as well as the production, weight, thickness, material types and properties, and the arrangement of scales determine the level of protection and comfort offered by stab-resistant vests. Currently, the production of stab-proof gear-based 3D printing technology is evaluated, using lightweight materials (aramid) in the form of segmented scales inspired by nature. As the protection performance and wear comfort of stab-proof gear is enhanced, the willingness of security, control, transport, custom, and correction officers to wear them can be significantly increased in an endeavor to ensure that fatal injuries will decrease significantly.

scholarly journals Gromov-Wasserstein optimal transport to align single-cell multi-omics data

2020 ◽  
Author(s):  
Pinar Demetci ◽  
Rebecca Santorella ◽  
Björn Sandstede ◽  
William Stafford Noble ◽  
Ritambhara Singh
Keyword(s):  
Single Cell ◽  
Optimal Transport ◽  
Learning Algorithm ◽  
State Of The Art ◽  
Single Cells ◽  
Wasserstein Distance ◽  
Cell Alignment ◽  
Shared Space ◽  
Real World Datasets ◽  
Unsupervised Algorithms

AbstractData integration of single-cell measurements is critical for understanding cell development and disease, but the lack of correspondence between different types of measurements makes such efforts challenging. Several unsupervised algorithms can align heterogeneous single-cell measurements in a shared space, enabling the creation of mappings between single cells in different data domains. However, these algorithms require hyperparameter tuning for high-quality alignments, which is difficult in an unsupervised setting without correspondence information for validation. We present Single-Cell alignment using Optimal Transport (SCOT), an unsupervised learning algorithm that uses Gromov Wasserstein-based optimal transport to align single-cell multi-omics datasets. We compare the alignment performance of SCOT with state-of-the-art algorithms on four simulated and two real-world datasets. SCOT performs on par with state-of-the-art methods but is faster and requires tuning fewer hyperparameters. Furthermore, we provide an algorithm for SCOT to use Gromov Wasserstein distance to guide the parameter selection. Thus, unlike previous methods, SCOT aligns well without using any orthogonal correspondence information to pick the hyperparameters. Our source code and scripts for replicating the results are available at https://github.com/rsinghlab/SCOT.

scholarly journals K-mer counting with low memory consumption enables fast clustering of single-cell sequencing data without read alignment

2019 ◽  
Author(s):  
Christina Huan Shi ◽  
Kevin Y. Yip
Keyword(s):  
Single Cell ◽  
State Of The Art ◽  
Rna Seq ◽  
Sequencing Data ◽  
Memory Consumption ◽  
Analysis Pipeline ◽  
Cell Clusters ◽  
Single Cell Sequencing ◽  
Sequencing Errors ◽  
Full Analysis

AbstractK-mer counting has many applications in sequencing data processing and analysis. However, sequencing errors can produce many false k-mers that substantially increase the memory requirement during counting. We propose a fast k-mer counting method, CQF-deNoise, which has a novel component for dynamically identifying and removing false k-mers while preserving counting accuracy. Compared with four state-of-the-art k-mer counting methods, CQF-deNoise consumed 49-76% less memory than the second best method, but still ran competitively fast. The k-mer counts from CQF-deNoise produced cell clusters from single-cell RNA-seq data highly consistent with CellRanger but required only 5% of the running time at the same memory consumption, suggesting that CQF-deNoise can be used for a preview of cell clusters for an early detection of potential data problems, before running a much more time-consuming full analysis pipeline.

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