scholarly journals Trace Contamination Measurements Using Heavy Ion Backscattering Spectrometry

1994 ◽  
Vol 354 ◽  
Author(s):  
J.A. Knapp ◽  
J.C. Banks ◽  
D.K. Brice
Keyword(s):  
Heavy Ions ◽  
Solid Angle ◽  
Ion Beam ◽  
Heavy Ion ◽  
Low Energy ◽  
Measuring Surface ◽  
Thin Carbon ◽  
Materials Research ◽  
Low Levels ◽  
Ion Backscattering

AbstractHeavy Ion Backscattering Spectrometry (HIBS) is a tool for measuring surface contamination at levels much lower than previously achievable with ion beam analyses. Many areas of materials research and development require very low levels of impurities, with advanced microelectronics as the best example. HIBS uses low-energy, heavy ions for analysis, taking advantage of the increased backscattering yield which can be obtained from high Z ion beams at low energy. Background due to increased yield from the substrate is eliminated by a thin carbon foil as part of the detector, with a thickness chosen to range out ions scattered from the substrate and allow only ions scattered from impurities heavier than the substrate to reach the detector. Our research system, using 150-200 keV N+ beams and a single time-of-flight detector optimized for large solid angle, has achieved a sensitivity ranging from ∼5×1010 atoms/cm2 for Fe to ∼1×109 atoms/cm for Au on Si, without preconcentration. A stand-alone HIBS prototype which we have developed for SEMATECH is expected to reach detection limits of -5×10 atoms/cm for Fe and -1×10 atoms/cm for Au on Si. In this paper we discuss in detail the factors which affect sensitivity for HIBS.

A low-energy ion beam from alkali heavy-ion reaction products

1994 ◽  
Vol 351 (2-3) ◽  
pp. 256-260 ◽  
Author(s):  
J.A. Behr ◽  
S.B. Cahn ◽  
S.B. Dutta ◽  
A. Ghosh ◽  
G. Gwinner ◽  
...  
Keyword(s):  
Ion Beam ◽  
Heavy Ion ◽  
Low Energy ◽  
Reaction Products

scholarly journals Experimental investigation of ion beam transport in laser initiated plasma channels

2002 ◽  
Vol 20 (4) ◽  
pp. 559-563 ◽  
Author(s):  
D. PENACHE ◽  
C. NIEMANN ◽  
A. TAUSCHWITZ ◽  
R. KNOBLOCH ◽  
S. NEFF ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Heavy Ions ◽  
Plasma Channel ◽  
Ion Beam ◽  
Heavy Ion ◽  
High Current ◽  
Beam Transport ◽  
Electrode Gap ◽  
Discharge Gap ◽  
The Magnetic Field

The aim of the presented experiments is to study the transport of a heavy ion beam in a high-current plasma channel. The discharge is initiated in NH3 gas at pressures between 2 and 20 mbar by a line-tuned CO2 laser. A stable discharge over the entire electrode gap (0.5 m) was achieved for currents up to 60 kA. Concerning the ion beam transport, the magnetic field distribution inside the plasma channel has to be known. The ion-optical properties of the plasma channel have been investigated using different species of heavy ions (C, Ni, Au, U) with 11.4 MeV/u during six runs at the Gesellschaft für Schwerionenforschungs-UNILAC linear accelerator. The high magnetic field allowed the accomplishment of one complete betatron oscillation along the discharge channel. The results obtained up to now are very promising and suggest that, by scaling the discharge gap to longer distances, the beam transport over several meters is possible with negligible losses.

Effect of Cascade Remnants on Freely Migrating Defects in Cu -1 % Au Alloys

1995 ◽  
Vol 396 ◽  
Author(s):  
A. Iwase ◽  
L. E. Rehn ◽  
P. M. Baldo ◽  
L. Funk
Keyword(s):  
Heavy Ions ◽  
Ion Irradiation ◽  
Ion Beam ◽  
Heavy Ion ◽  
The Other ◽  
Inert Gas ◽  
Heavy Ion Irradiation ◽  
Simultaneous Irradiation ◽  
Radiation Induced ◽  
Cu Ions

AbstractThe effects of cascade remnants on Freely Migrating Defects (FMD) were studied by measuring Radiation-Induced Segregation (RIS) in Cu-l%Au at 400°C during simultaneous irradiation with 1.5-MeV He and (400-800)-keV heavy ions (Ne, Ar or Cu). The large RIS observed during 1.5-MeV He-only irradiation was dramatically suppressed under simultaneous heavy ion irradiation. For Cu simultaneous irradiation, the suppression disappeared immediately after the Cu irradiation ceased, while for simultaneous inert gas (Ne or Ar) irradiation, the suppression persisted after the ion beam was turned off. These results demonstrate that the displacement cascades created by heavy ions introduce additional annihilation sites, which reduce the steady-state FMD concentrations. As the cascade remnants produced by Cu ions are thermally unstable at 400°C, the RIS suppression occurs only during simultaneous irradiation. On the other hand, the inert gas atoms which accumulate in the specimen apparently stabilize the cascade remnants, allowing the suppression to persist.

scholarly journals Laser-driven acceleration of heavy ions at ultra-relativistic laser intensity

2018 ◽  
Vol 36 (4) ◽  
pp. 507-512 ◽  
Author(s):  
J. Domański ◽  
J. Badziak ◽  
M. Marchwiany
Keyword(s):  
Laser Pulse ◽  
Heavy Ions ◽  
Ion Beam ◽  
Heavy Ion ◽  
High Energy ◽  
Target Thickness ◽  
High Energy Density ◽  
Ion Acceleration ◽  
Acceleration Process ◽  
Particle In Cell

AbstractThis paper presents the results of numerical investigations into the acceleration of heavy ions by a multi-PW laser pulse of ultra-relativistic intensity, to be available with the Extreme Light Infrastructure lasers currently being built in Europe. In the numerical simulations, performed with the use of a multi-dimensional (2D3V) particle-in-cell code, the thorium target with a thickness of 50 or 200 nm was irradiated by a circularly polarized 20 fs laser pulse with an energy of ~150 J and an intensity of 1023 W/cm2. It was found that the detailed run of the ion acceleration process depends on the target thickness, though in both considered cases the radiation pressure acceleration (RPA) stage of ion acceleration is followed by a sheath acceleration stage, with a significant role in the post-RPA stage being played by the ballistic movement of ions. This hybrid acceleration mechanism leads to the production of an ultra-short (sub-picosecond) multi-GeV ion beam with a wide energy spectrum and an extremely high intensity (>1021 W/cm2) and ion fluence (>1017 cm−2). Heavy ion beams of such extreme parameters are hardly achievable in conventional RF-driven ion accelerators, so they could open the avenues to new areas of research in nuclear and high energy density physics, and possibly in other scientific domains.

Comparison doses of secondary neutron with the heavy ions in a 75-mev/n heavy ion beam

2005 ◽  
Vol 117 (4) ◽  
pp. 369-372 ◽  
Author(s):  
Bingrong Dang ◽  
Wenjian Li ◽  
Jing Wang
Keyword(s):  
Heavy Ions ◽  
Ion Beam ◽  
Heavy Ion ◽  
Secondary Neutron ◽  
Heavy Ion Beam
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