APL Nameplate
  • Volume/Page
  • Keyword
  • DOI
  • Citation
  • Advanced
   
 
 
 

Flickr Twitter iResearch App Facebook

BROWSE VOLUMES

Year Range: 
Search Issue | RSS Feeds RSS
Previous Issue Next Issue

9 Jul 2012

Volume 101, Issue 2, Articles (02xxxx)

Issue Cover Spotlight Figure

Appl. Phys. Lett. 101, 023101 (2012); http://dx.doi.org/10.1063/1.4731792 (4 pages)

Feng Wang, Ayan Chakrabarty, Fred Minkowski, Kai Sun, and Qi-Huo Wei
Enlarge Image | Read More
Return to All Sections
back to top
RSS Feeds

Multi-pulse enhanced laser ion acceleration using plasma half cavity targets

G. G. Scott, J. S. Green, V. Bagnoud, C. Brabetz, C. M. Brenner, D. C. Carroll, D. A. MacLellan, A. P. L. Robinson, M. Roth, C. Spindloe, F. Wagner, B. Zielbauer, P. McKenna, and D. Neely

Appl. Phys. Lett. 101, 024101 (2012); http://dx.doi.org/10.1063/1.4734397 (4 pages) | Cited 1 time

Online Publication Date: 10 July 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report on a plasma half cavity target design for laser driven ion acceleration that enhances the laser to proton energy conversion efficiency and has been found to modify the low energy region of the proton spectrum. The target design utilizes the high fraction of laser energy reflected from an ionized surface and refocuses it such that a double pulse interaction is attained. We report on numerical simulations and experimental results demonstrating that conversion efficiencies can be doubled, compared to planar foil interactions, when the secondary pulse is delivered within picoseconds of the primary pulse.
Show PACS
52.38.Kd Laser-plasma acceleration of electrons and ions
52.65.-y Plasma simulation
02.60.-x Numerical approximation and analysis
52.25.Jm Ionization of plasmas
52.25.Os Emission, absorption, and scattering of electromagnetic radiation

Demonstration of a low electromagnetic pulse laser-driven argon gas jet x-ray source

N. L. Kugland, B. Aurand, C. G. Brown, C. G. Constantin, E. T. Everson, S. H. Glenzer, D. B. Schaeffer, A. Tauschwitz, and C. Niemann

Appl. Phys. Lett. 101, 024102 (2012); http://dx.doi.org/10.1063/1.4734506 (4 pages)

Online Publication Date: 11 July 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Laser-produced plasmas are often used as bright x-ray backlighters for time-resolved plasma diagnostics, but such backlighters simultaneously generate damaging electromagnetic pulse (EMP). A laser-driven Ar gas jet x-ray source has been measured with magnetic flux B-dot probes to produce 20 times ±37% less integrated EMP in the 0.5–2.5 GHz band than a solid chlorinated plastic foil, while retaining 85% of the laser to ≈3 keV x-ray conversion efficiency. These results are important for future backlighter development, since tailoring target density may provide a way to reduce EMP even as laser power increases.
Show PACS
52.25.Os Emission, absorption, and scattering of electromagnetic radiation
52.70.Ds Electric and magnetic measurements
52.75.-d Plasma devices

Time resolved optical emission images of an atmospheric pressure plasma jet with transparent electrodes

N. Puač, D. Maletić, S. Lazović, G. Malović, A. Đorđević, and Z. Lj. Petrović

Appl. Phys. Lett. 101, 024103 (2012); http://dx.doi.org/10.1063/1.4735156 (4 pages) | Cited 4 times

Online Publication Date: 11 July 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We study development of plasma packages in atmospheric pressure plasma jet from their formation as a discharge close to the instantaneous cathode, following their motion between and inside the electrodes up to their emergence at the edge of the glass tube and formation of a plasma bullet. Inside both electrodes, plasma is concentrated close to the walls and is bright, while outside it is located at the axis. This paper opens issues of the geometry of electrodes, fields, and atomic processes, allowing some predictions to be made about pertinent mechanisms.
Show PACS
52.25.Os Emission, absorption, and scattering of electromagnetic radiation
52.50.Dg Plasma sources
52.70.Kz Optical (ultraviolet, visible, infrared) measurements
52.75.-d Plasma devices
52.80.-s Electric discharges

Minimal energy control of a nanoelectromechanical memory element

N. A. Khovanova and J. Windelen

Appl. Phys. Lett. 101, 024104 (2012); http://dx.doi.org/10.1063/1.4736566 (4 pages) | Cited 1 time

Online Publication Date: 11 July 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The Pontryagin minimal energy control approach has been applied to minimise the switching energy in a nanoelectromechanical memory system and to characterise global stability of the oscillatory states of the bistable memory element. A comparison of two previously experimentally determined pulse-type control signals with Pontryagin control function has been performed, and the superiority of the Pontryagin approach with regard to power consumption has been demonstrated. An analysis of global stability shows how values of minimal energy can be utilized in order to specify equally stable states.
Show PACS
85.85.+j Micro- and nano-electromechanical systems (MEMS/NEMS) and devices
84.30.Sk Pulse and digital circuits

Focused high frequency needle transducer for ultrasonic imaging and trapping

Hsiu-Sheng Hsu, Fan Zheng, Ying Li, Changyang Lee, Qifa Zhou, and K. Kirk Shung

Appl. Phys. Lett. 101, 024105 (2012); http://dx.doi.org/10.1063/1.4736731 (3 pages) | Cited 4 times

Online Publication Date: 11 July 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A miniature focused needle transducer (<1 mm) was fabricated using the press-focusing technique. The measured pulse-echo waveform showed the transducer had center frequency of 57.5 MHz with 54% bandwidth and 14 dB insertion loss. To evaluate the performance of this type of transducer, invitro ultrasonic biomicroscopy imaging on the rabbit eye was obtained. Moreover, a single beam acoustic trapping experiment was performed using this transducer. Trapping of targeted particle size smaller than the ultrasonic wavelength was observed. Potential applications of these devices include minimally invasive measurements of retinal blood flow and single beam acoustic trapping of microparticles.
Show PACS
43.38.Fx Piezoelectric and ferroelectric transducers
43.80.Vj Acoustical medical instrumentation and measurement techniques
85.85.+j Micro- and nano-electromechanical systems (MEMS/NEMS) and devices
87.85.Ox Biomedical instrumentation and transducers, including micro-electro-mechanical systems (MEMS)
43.35.Ty Other physical effects of sound
43.35.Yb Ultrasonic instrumentation and measurement techniques

Structural, dynamical, and electronic properties of transition metal-doped Ge2Sb2Te5 phase-change materials simulated by ab initio molecular dynamics

J. M. Skelton, T. H. Lee, and S. R. Elliott

Appl. Phys. Lett. 101, 024106 (2012); http://dx.doi.org/10.1063/1.4736577 (4 pages) | Cited 1 time

Online Publication Date: 12 July 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Doping has been widely employed as a means to improve the properties of Ge-Sb-Te (GST) phase-change materials for application in digital storage devices. However, there has been little investigation into how these dopants influence the structure and atomic dynamics of the host material. We have performed ab initio molecular-dynamics simulations of the complete phase-change cycle in undoped and Mn/Zn-doped model systems of Ge2Sb2Te5. Our findings shed valuable light on how transition-metal atoms behave within and influence a GST host matrix, and might be used predictively to select future transition metal dopants for tuning the material properties for non-volatile memory applications.
Show PACS
71.23.Cq Amorphous semiconductors, metallic glasses, glasses
61.72.up Other materials
71.15.Pd Molecular dynamics calculations (Car-Parrinello) and other numerical simulations

Design and measurements of an electrically small, broad bandwidth, non-Foster circuit-augmented protractor antenna

Ning Zhu and Richard W. Ziolkowski

Appl. Phys. Lett. 101, 024107 (2012); http://dx.doi.org/10.1063/1.4736996 (4 pages) | Cited 1 time

Online Publication Date: 13 July 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A broad bandwidth, electrically small, metamaterial-inspired protractor antenna was designed, fabricated and tested around 300 MHz. Its broad bandwidth property was achieved by augmenting the protractor-shaped near-field resonant parasitic (NFRP) element with a non-Foster circuit. The resulting active NFRP element provided the means to surpass the fundamental passive limits. The measurement results for this non-Foster protractor antenna showed more than a 10 times increase of the 10 dB fractional bandwidth (FBW10dB) of the original passive version. The corresponding half-power bandwidth (BW3dB) was more than 8.24 times the passive upper bound.
Show PACS
84.40.Ba Antennas: theory, components and accessories
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close