scholarly journals Development and beam commissioning of a continuous-wave window-type radio-frequency quadrupole

Author(s):  
P. P. Gan ◽  
K. Zhu ◽  
Q. Fu ◽  
H. P. Li ◽  
M. J. Easton ◽  
...  
2020 ◽  
Vol 29 (02) ◽  
pp. 1950111
Author(s):  
Qiuyun Tan ◽  
Kun Zhu ◽  
Pingping Gan ◽  
Qi Fu ◽  
Haipeng Li ◽  
...  

As high-intensity beams are required for various applications, high-power, high-current, continuous-wave (CW) radio-frequency quadrupole (RFQ) accelerators have become a research focus in recent years and also a direction for development in the future. To master and accumulate the advanced technology in design, fabrication and operation of high-current CW RFQs, the RFQ group at Peking University has built a window-type CW RFQ, operating at 162.5[Formula: see text]MHz, to accelerate a 50-mA deuteron beam from 50[Formula: see text]keV to 1[Formula: see text]MeV. It is the first relatively high-frequency window-type CW RFQ in the world. A [Formula: see text] ion beam extracted from an electron cyclotron resonance (ECR) ion source was used for the beam commissioning because deuteron beam acceleration will produce a serious radiation risk. We compared and analyzed the measurement results obtained during the beam commissioning with simulations. The data show good consistency in many respects. For the discrepancies, we explain the issues in detail. We achieved stable and robust acceleration of about 1.5[Formula: see text]mA CW [Formula: see text] for 1[Formula: see text]h. Finally, we discuss the differences between [Formula: see text] ion beam acceleration and deuteron beam acceleration.


Author(s):  
S. V. Kutsaev ◽  
B. Mustapha ◽  
P. N. Ostroumov ◽  
A. Barcikowski ◽  
D. Schrage ◽  
...  

Author(s):  
P. N. Ostroumov ◽  
B. Mustapha ◽  
A. Barcikowski ◽  
C. Dickerson ◽  
A. A. Kolomiets ◽  
...  

2000 ◽  
Vol 71 (2) ◽  
pp. 767-770 ◽  
Author(s):  
Joseph D. Sherman ◽  
Gerald O. Bolme ◽  
Lash D. Hansborough ◽  
Thomas W. Hardek ◽  
Debora M. Kerstiens ◽  
...  

2020 ◽  
Vol 10 (19) ◽  
pp. 6885
Author(s):  
Sahar Ujan ◽  
Neda Navidi ◽  
Rene Jr Landry

Radio Frequency Interference (RFI) detection and characterization play a critical role in ensuring the security of all wireless communication networks. Advances in Machine Learning (ML) have led to the deployment of many robust techniques dealing with various types of RFI. To sidestep an unavoidable complicated feature extraction step in ML, we propose an efficient Deep Learning (DL)-based methodology using transfer learning to determine both the type of received signals and their modulation type. To this end, the scalogram of the received signals is used as the input of the pretrained convolutional neural networks (CNN), followed by a fully-connected classifier. This study considers a digital video stream as the signal of interest (SoI), transmitted in a real-time satellite-to-ground communication using DVB-S2 standards. To create the RFI dataset, the SoI is combined with three well-known jammers namely, continuous-wave interference (CWI), multi- continuous-wave interference (MCWI), and chirp interference (CI). This study investigated four well-known pretrained CNN architectures, namely, AlexNet, VGG-16, GoogleNet, and ResNet-18, for the feature extraction to recognize the visual RFI patterns directly from pixel images with minimal preprocessing. Moreover, the robustness of the proposed classifiers is evaluated by the data generated at different signal to noise ratios (SNR).


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