scholarly journals Preacceleration of the multicharged ions with the different A/Z ratios in single RFQ channel

2018 ◽  
pp. 49-56
Author(s):  
Vladislav Altsybeyev ◽  
Yuri Svistunov ◽  
Alexander Durkin ◽  
Dmitri Ovsyannikov

The preacceleration of multicharged ions with the different A/Z ratios extracted from electron cyclotron resonance (ECR) sources is discussed in this report. The capture ratio, emittances and current values of multicharged ions may be better if the ions are preaccelerated before their injection into a booster synchrotron. There is a considerable possibility of separate preacceleration of multicharged ions with different A/Z ratios in a single radio-frequency quadrupole (RFQ) channel. The magnitude of the injection energy into RFQ is about a few keV/u whereas the magnitudes of the injection energy into booster or following linac cascade are 300 keV/u. In addition in this paper we discuss the approach of the fast channel parameter optimization technique by using swarm computations and gradient descend for improving the capture ratio. The optimizations aimed at changing the regular part of the RFQ or matching section profile to improve the matching of the arbitrary oriented in phase space input beam.

2011 ◽  
Vol 131 (4) ◽  
pp. 654-666
Author(s):  
Qingliang Zhang ◽  
Takahiro Ueno ◽  
Noboru Morita

Author(s):  
Krishna Rudraraju Chaitanya ◽  
P. Mallikarjuna Rao ◽  
K. V. S. N. Raju ◽  
G. S. N. Raju

Author(s):  
. Geetanjli

The power control in CDMA systems, grant numerous users to share resources of the system uniformly between each other, leading to expand capacity. With convenient power control, capacity of CDMA system is immense in contrast of frequency division multiple access (FDMA) and time division multiple access (TDMA). If power control is not achieved numerous problems such as the near-far effect will start to monopolize and consequently will reduce the capacity of the CDMA system. However, when the power control in CDMA systems is implemented, it allows numerous users to share resources of the system uniformly between themselves, leading to increased capacity For power control in CDMA system optimization algorithms i.e. genetic algorithm & particle swarm algorithm can be used which regulate a convenient power vector. These power vector or power levels are dogged at the base station and announce to mobile units to alter their transmitting power in accordance to these levels. The performances of the algorithms are inspected through both analysis and computer simulations, and compared with well-known algorithms from the literature.


Author(s):  
Ramachandra Chitakudige ◽  
Sarat Kumar Dash ◽  
A.M. Khan

Abstract Detection of both Insufficient Buried Contact (IBC) and cell-to-cell short defects is quite a challenging task for failure analysis in submicron Dynamic Random Access Memory (DRAM) devices. A combination of a well-controlled wet etch and high selectivity poly silicon etch is a key requirement in the deprocessing of DRAM for detection of these types of failures. High selectivity poly silicon etch methods have been reported using complicated system such as ECR (Electron Cyclotron Resonance) Plasma system. The fact that these systems use hazardous gases like Cl2, HBr, and SF6 motivates the search for safer alternative deprocessing chemistries. The present work describes high selectivity poly silicon etch using simple Reactive Ion Etch (RIE) plasma system using less hazardous gases such as CF4, O2 etc. A combination of controlled wet etch and high selectivity poly silicon etch have been used to detect both IBC and cell-to-cell shorts in submicron DRAMs.


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