scholarly journals High-power proton accelerators for pulsed spallation neutron sources

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Hideaki Hotchi
Keyword(s):  
High Power ◽  
Power Performance ◽  
Beam Loss ◽  
Neutron Sources ◽  
Hands On ◽  
Beam Handling ◽  
Loss Control

AbstractWith the spread of accelerator-driven pulsed spallation neutron sources and increasing need for higher neutron fluxes, the high-power performance of proton accelerators has greatly advanced from a few kilowatts to more than 1 MW in the last four decades. The most important concerns to realize such a high-power beam operation are controlling and minimizing beam loss, which are essential for sustainable beam operation that allows hands-on maintenance. This paper reviews key devices and beam handling techniques for beam loss control employed in the high-power proton accelerators that are currently in operation for pulsed spallation neutron sources, including their operational status and future upgrade plan.

Influence of barrier thickness on the high-power performance of AlGaN/GaN HEMTs

2001 ◽  
Vol 22 (11) ◽  
pp. 504-506 ◽  
Author(s):  
V. Tilak ◽  
B. Green ◽  
V. Kaper ◽  
H. Kim ◽  
T. Prunty ◽  
...  
Keyword(s):  
High Power ◽  
Barrier Thickness ◽  
Power Performance ◽  
Gan Hemts

High-Temperature, High-Power Performance of Ceramic Filter Capacitors

2011 ◽  
Vol 2011 (HITEN) ◽  
pp. 000027-000029
Author(s):  
K. Bridger ◽  
A. Cooke ◽  
D. Kohlhafer ◽  
R. Strite ◽  
W. Schulze ◽  
...  
Keyword(s):  
High Temperature ◽  
High Temperatures ◽  
High Power ◽  
Ceramic Filter ◽  
Power Performance ◽  
Output Stage ◽  
The Real Estate ◽  
Military Vehicles ◽  
New Family ◽  
Aircraft Component

Power conversion electronics in military vehicles and aircraft are currently experiencing high temperatures and future generations will see these temperatures rise even higher. The high temperatures arise not only from the environment but also from high power dissipation in the components themselves. Capacitors can occupy almost 50% of the real estate in some power converters and these capacitors are subjected to very high currents at high frequencies in dc-dc converters or 60-Hz 120 VAC in the output stage of an inverter. Dissipation resulting from the high power levels can lead to internal capacitor temperatures at least 50°C above their ambient and so for military hybrid electric vehicles (HEVs) capacitors are expected to reach at least 150°C and possibly 200°C, while future aircraft component temperatures are expected to exceed 250°C. A new family of high-temperature dielectrics based on sodium bismuth titanate has been developed by these authors and capacitors are now available from Novacap under the trade name “Type H” or “Type HA”. This paper examines the high-frequency, high-current and 60-Hz, 120-VAC performance of these capacitors including an estimate of internal heating. The primary operating temperature range studied is −40 to +150°C, although some higher temperature data are also presented.

A 4.2-to-5.4 GHz stacked GaAs HBT power amplifier for C-band applications

Circuit World ◽  
2020 ◽  
Vol 46 (4) ◽  
pp. 243-248
Author(s):  
Min Liu ◽  
Panpan Xu ◽  
Jincan Zhang ◽  
Bo Liu ◽  
Liwen Zhang
Keyword(s):  
Output Power ◽  
Power Amplifier ◽  
High Power ◽  
High Efficiency ◽  
Common Source ◽  
Power Performance ◽  
Matching Network ◽  
Content Type ◽  
Power Added Efficiency ◽  
Saturated Output Power

Purpose Power amplifiers (PAs) play an important role in wireless communications because they dominate system performance. High-linearity broadband PAs are of great value for potential use in multi-band system implementation. The purpose of this paper is to present a cascode power amplifier architecture to achieve high power and high efficiency requirements for 4.2∼5.4 GHz applications. Design/methodology/approach A common emitter (CE) configuration with a stacked common base configuration of heterojunction bipolar transistor (HBT) is used to achieve high power. T-type matching network is used as input matching network. To increase the bandwidth, the output matching networks are implemented using the two L-networks. Findings By using the proposed method, the stacked PA demonstrates a maximum saturated output power of 26.2 dBm, a compact chip size of 1.17 × 0.59 mm2 and a maximum power-added efficiency of 46.3 per cent. The PA shows a wideband small signal gain with less than 3 dB variation over working frequency. The saturated output power of the proposed PA is higher than 25 dBm between 4.2 and 5.4 GHz. Originality/value The technology adopted for the design of the 4.2-to-5.4 GHz stacked PA is the 2-µm gallium arsenide HBT process. Based on the proposed method, a better power performance of 3 dB improvement can be achieved as compared with the conventional CE or common-source amplifier because of high output stacking impedance.

Measurement and modelling of the high-power performance of carbon-based supercapacitors

2000 ◽  
Vol 91 (1) ◽  
pp. 68-76 ◽  
Author(s):  
Peter J. Mahon ◽  
George L. Paul ◽  
Sarkis M. Keshishian ◽  
Anthony M. Vassallo
Keyword(s):  
High Power ◽  
Power Performance ◽  
Carbon Based
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