A differentially pumped and recirculating gas target

Self Cite

168

130

Abstract. The d(d,n)3He and d(d,p)t fusion reactionshave been studied at center-of-mass energies E = 1.6 to 130 keV using intense beam currents from 30, 100, and 450 kV accelerators in combination with detectors in close and far geometry. The cross sesction ratio, (d,p), approaches unity (within 2%) at low energies; thus there is no experimental evidence for the Oppenheimer-Phillips effect at subcoulomb energies. R(E)=a(d,n)/cr The cross sections of d(d,p)t at E<10 keV show clearevidence for electron screening effects. However, the observed cross section enhancement is significantly larger than can be accounted for from available atomic physics models.

Section: Measurements In Far Geometrymentioning

confidence: 99%

Oppenheimer-Phillips effect and electron screening ind+ d fusion reactions

Greife

Gorris

Junker

et al. 1995

Self Cite

168

130

“…For the measurement of angular distributions, excitation functions, and absolute cross sections over a wide range of energies (E = 30 to 1450 keV; 400 kV and 4 MV accelerators), a disk-shaped target chamber [28,30] (20 cm diameter, 3 cm height) was used. A beam entrance aperture A (4 mm diameter) was installed at a distance of 2.5 cm from the center of the chamber for the H(TLi, c~)4He studies, and at 11.2 cm for the H(6Li, ~)3He and D(6Li, c%4He studies.…”

Section: Gas Target Setupsmentioning

confidence: 99%

“…In the case of Li ion beams, a windowless gas target system [28][29][30] of four pumping stages (filled with hydrogen gas) was used. The beam entered the target chamber through 5 apertures of high pumping impedance and was stopped in a 2 W or 20 W beam calorimeter.…”

Section: Gas Target Setupsmentioning

confidence: 99%

Isotopic dependence of electron screening in fusion reactions

Engstler

Raimann

Angulo

et al. 1992

Self Cite

137

176

The fusion reactions 6Li (p, cQ3He, 6Li(d,~)4He, and 7Li(p, c~)4He have been studied over the c.m. energy range E = 10 to 1450 keV. Each reaction involved the use of hydrogen projectiles and LiF solid targets as well as Li projectiles and hydrogen molecular gas targets. In all cases the effects of electron screening on the low-energy fusion cross sections (exponential enhancement) have been observed; the effects are somewhat stronger in the case of atomic p or d projectiles compared to the case of molecular H 2 or D2 gas targets. If isotopic effects on electron screening are negligible, all three reactions should exhibit the same enhancements for each set of experimental techniques. The measurements confirmed this expectation to a large extent.

“…A windowless (differentially pumped) gas target system with five pumping stages was used [24,25] (Fig. 1), which [36], and 1.9 _+ 0.3 [37] h Range and stopping power values are obtained from the TRIM program [13].…”

Section: Windowless Gas Target Systemmentioning

confidence: 99%

Hydrogen depth profiling using18O ions

Becker

Bähr

Berheide

et al. 1995

Self Cite

Abstract. Nuclear resonant reaction analysis techniques for hydrogen depth profiling in solid materials typically have used 1 s N ion beams at 6.40 MeV and ~ 9F ion beams at 6.42 MeV, which require a tandem accelerator. We report a new technique using an ~sO ion beam at a resonance energy of 2.70 MeV, which requires only a single stage accelerator. Improved values of the nuclear parameters for the 2.70 MeV (180) and 6.40 MeV (~SN) resonances are reported. The beam energy spread was investigated for different ions and ion charge states and found to scale with the charge state. Data obtained using atomic and molecular gas targets reveal the research potential of Doppler spectroscopy. Examples of hydrogen depth profiling in solid materials using lSN and I80 ion beams are presented.