scholarly journals Correction of beam-steering effects in low-velocity superconducting quarter-wave cavities

2001 ◽  
Vol 4 (11) ◽  
Author(s):  
P. N. Ostroumov ◽  
K. W. Shepard
Keyword(s):  
Beam Steering ◽  
Low Velocity ◽  
Quarter Wave

Measurement of beam steering and RF defocusing effect for a quarter-wave resonator

2019 ◽  
Vol 28 (03) ◽  
pp. 1950019
Author(s):  
Yuanshuai Qin ◽  
Zhijun Wang ◽  
Huan Jia ◽  
Yuan He ◽  
Penghui Gao ◽  
...  
Keyword(s):  
Beam Steering ◽  
Proton Accelerator ◽  
Central Position ◽  
Linear Accelerators ◽  
Simulation Code ◽  
Beam Position ◽  
Quarter Wave Resonator ◽  
Wave Resonator ◽  
Modern Physics ◽  
Quarter Wave

Quarter-wave resonators (QWRs) are being widely used in linear accelerators (linac) for acceleration of ions with low-[Formula: see text] velocity. Two effects of this kind of cavities are beam steering effect and RF defocusing effect caused by geometric asymmetry. Measurement for the two effects has been conducted by using beam position monitors (BPMs) and wires for a QWR type buncher whose frequency is 162.5[Formula: see text]MHz at Institute of Modern Physics (IMP), Chinese Academy of Sciences (CAS). Since experiment and simulation matches well, beam central position and beam envelope could be predicted in simulation code, which is beneficial for high-intensity proton accelerator design and commissioning.

scholarly journals A triple-band antenna array for next-generation wireless and satellite-based applications

2014 ◽  
Vol 8 (1) ◽  
pp. 71-80 ◽  
Author(s):  
Asghar A. Razzaqi ◽  
Bilal A. Khawaja ◽  
Mehrab Ramzan ◽  
Muhammad Javed Zafar ◽  
Syeda Areeba Nasir ◽  
...  
Keyword(s):  
Antenna Array ◽  
Antenna Arrays ◽  
Beam Steering ◽  
Optimization Techniques ◽  
Single Element ◽  
Next Generation ◽  
Antenna Performance ◽  
Quarter Wave ◽  
Wave Transformer ◽  
Triple Band

In this paper, a triple-band 1 × 2 and 1 × 4 microstrip patch antenna array for next-generation wireless and satellite-based applications are presented. The targeted frequency bands are 3.6, 5.2 and 6.7 GHz, respectively. Simple design procedures and optimization techniques are discussed to achieve better antenna performance. The antenna is designed and simulated using Agilent ADS Momentum using FR4 substrate (εr= 4.2 and h = 1.66 mm). The main patch of the antenna is designed for 3.6 GHz operation. A hybrid feed technique is used for antenna arrays with quarter-wave transformer-based network to match the impedance from the feed-point to the antenna to 50 Ω. The antenna is optimized to resonate at triple-bands by using two symmetrical slits. The single-element triple-band antenna is fabricated and characterized, and a comparison between the simulated and measured antenna is presented. The achieved simulated impedance bandwidths/gains for the 1 × 2 array are 1.67%/7.75, 1.06%/7.7, and 1.65%/9.4 dBi and for 1 × 4 array are 1.67%/10.2, 1.45%/8.2, and 1.05%/10 dBi for 3.6, 5.2, and 6.7 GHz bands, respectively, which are very practical. These antenna arrays can also be used for advanced antenna beam-steering systems.

Functional Metasurface Quarter-Wave Plates for Simultaneous Polarization Conversion and Beam Steering

ACS Nano ◽  
2021 ◽  
Author(s):  
Yadong Deng ◽  
Cuo Wu ◽  
Chao Meng ◽  
Sergey I. Bozhevolnyi ◽  
Fei Ding
Keyword(s):  
Beam Steering ◽  
Polarization Conversion ◽  
Quarter Wave

Beam steering correction of the quarter wave resonator in the HISCL

2014 ◽  
Vol 38 (10) ◽  
pp. 107007
Author(s):  
Shu-Hui Liu ◽  
Zhi-Jun Wang ◽  
Cong Zhang ◽  
Yuan He
Keyword(s):  
Beam Steering ◽  
Quarter Wave Resonator ◽  
Wave Resonator ◽  
Quarter Wave

Motions of neutral hydrogen at high latitudes

1967 ◽  
Vol 31 ◽  
pp. 265-278 ◽  
Author(s):  
A. Blaauw ◽  
I. Fejes ◽  
C. R. Tolbert ◽  
A. N. M. Hulsbosch ◽  
E. Raimond
Keyword(s):  
Surface Density ◽  
Velocity Dispersion ◽  
Neutral Hydrogen ◽  
Hydrogen Gas ◽  
High Latitudes ◽  
Low Velocity

Earlier investigations have shown that there is a preponderance of negative velocities in the hydrogen gas at high latitudes, and that in certain areas very little low-velocity gas occurs. In the region 100° <l< 250°, + 40° <b< + 85°, there appears to be a disturbance, with velocities between - 30 and - 80 km/sec. This ‘streaming’ involves about 3000 (r/100)2solar masses (rin pc). In the same region there is a low surface density at low velocities (|V| < 30 km/sec). About 40% of the gas in the disturbance is in the form of separate concentrations superimposed on a relatively smooth background. The number of these concentrations as a function of velocity remains constant from - 30 to - 60 km/sec but drops rapidly at higher negative velocities. The velocity dispersion in the concentrations varies little about 6·2 km/sec. Concentrations at positive velocities are much less abundant.

Atomic orientation effects in proton stopping at low velocity

1983 ◽  
Vol 41 ◽  
pp. 708-709
Author(s):  
Kin Lam
Keyword(s):  
Polycrystalline Material ◽  
Charged Particles ◽  
Target Material ◽  
Stopping Power ◽  
Low Velocity ◽  
Electronic Density ◽  
Interatomic Distances ◽  
Frame Work ◽  
Image Position ◽  
Atomic Orientation

The energy of moving ions in solid is dependent on the electronic density as well as the atomic structural properties of the target material. These factors contribute to the observable effects in polycrystalline material using the scanning ion microscope. Here we outline a method to investigate the dependence of low velocity proton stopping on interatomic distances and orientations.The interaction of charged particles with atoms in the frame work of the Fermi gas model was proposed by Lindhard. For a system of atoms, the electronic Lindhard stopping power can be generalized to the formwhere the stopping power function is defined as

Symmetric-pair antennas for beam steering, direction finding or isotropic-reception gain

1991 ◽  
Vol 138 (4) ◽  
pp. 368 ◽  
Author(s):  
R. Benjamin ◽  
W. Titze ◽  
P.V. Brennan ◽  
H.D. Griffiths
Keyword(s):  
Beam Steering ◽  
Direction Finding ◽  
Symmetric Pair
Sign in / Sign up

Export Citation Format

Share Document