Electron screening in d(d,p)t for deuterated metals and the periodic table

Raiola, F.; Migliardi, P.; Liu, Gang; Bonomo, C.; Gyürky, Gy.; Bonetti, R.; Broggini, C.; Christensen, N. E.; Corvisiero, P.; Cruz, J.; D’Onofrio, Antonio; Fülöp, Zs.; Gervino, G.; Gialanella, L.; Jesus, A.P.; Junker, M.; Langanke, K.; Prati, P.; Roca, V.; Rolfs, C.; Romano, M.; Somorjai, E.; Strieder, F.; Svane, A.; Terrasi, F.; Winter, J.

doi:10.1016/s0370-2693(02)02774-0

Cited by 89 publications

(81 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Note that eq. (1) differs from the analogous formula used in the previous works [3,4,[7][8][9], where the screening energy correction has been incorrectly applied also to the wavelength dependence of the cross-section being inversely proportional to the square root of E. At the very low deuteron energies investigated here this proper correction is significant. Since the bare nuclei S-factor is very well known from the precision measurements performed on the gas target [16], the experimentally determined enhancement of thick-target yields can be described by fitting the screening energy U e .…”

mentioning

confidence: 79%

The ² H(d,p) ³ H reaction in metallic media at very low energies

Czerski

Huke²,

Heide³

et al. 2004

Europhys. Lett.

View full text Add to dashboard Cite

Abstract. -Based on our experimental studies of the electron screening effect in the 2 H(d, p) 3 H reaction for five deuteron-implanted solid targets (C, Al, Zr, Pd, Ta), theoretical calculations have been performed within an improved dielectric function theory. The theory describes correctly the observed target material dependence of the screening energies, underestimating, however, the absolute values by about a factor of 2. Applying an effective screening energy approach, the theoretical cross-sections, thick-target yields as well as nuclear reaction rates have been calculated down to the energies corresponding to the conditions of so-called cold-fusion experiments. This allows for a comparison of the experimental results at higher energies with those achieved in the heavy-water electrolysis experiments.Introduction. -Nuclear reaction rates at very low projectile energies, far below the Coulomb barrier, are sensitive to the electronic properties of target materials. The electrons surrounding the reacting nuclei can increase the tunneling probability through the Coulomb barrier leading to an enhancement of nuclear reaction rates at low projectile energies. The electron screening effect was originally discussed due to its importance for dense astrophysical plasmas, where nuclear reaction rates can be increased by many orders of magnitudes [1]. Experimentally, the screening effect could be verified only fifteen years ago in gas target experiments [2] by an observation of an exponential-like increase of the measured cross-section for decreasing projectile energies compared to the cross-section expected for bare nuclei. Theoretically, this effect was described [3] by applying a conception of the electron screening energy resulting from the gain in the electron binding energy between the initially separated atoms and the finally united atom. In the experiments, the screening energy could be treated as an energy shift of the kinetic energy of the reacting nuclei causing an increase of the penetration probability through the Coulomb barrier.

show abstract

mentioning

confidence: 79%

The ² H(d,p) ³ H reaction in metallic media at very low energies

Czerski

Huke²,

Heide³

et al. 2004

Europhys. Lett.

View full text Add to dashboard Cite

show abstract

“…In this case, in fact, the 7 Be screening potential U D due to the free electrons is U D = −1 × 4 × U d+d , where 4 is Beryllium atomic number and U d+d is the electron screening value measured in d(d, p)t reaction in metallic environments. Between the metals considered, the highest U d+d value is 800 eV for Palladium [6], which gives U D = −3.2 keV. Since the electron capture process scales with the energy squared, the reduction factor of the decay probability is [(862 − 3.2)/862] 2 = 0.992, i.e.…”

Section: Resultsmentioning

confidence: 98%

“…Recently, it was discovered that the electron screening in d(d, p)t reaction for deuterated metals is much higher than the screening measured in d(d, p)t using deuterium gas target [6]. This feature has been explained by the Debye plasma model applied to the quasi-free electrons in metals: these electrons form an electron cloud around a e-mail: limata@na-infn.it the nucleus with a Debye radius which is about a factor 10 smaller than the atomic radius [7].…”

Section: Introductionmentioning

confidence: 93%

See 1 more Smart Citation

New measurement of 7Be half-life in different metallic environments

et al. 2006

View full text Add to dashboard Cite

Abstract. 7 Be decays via electron capture and therefore its half-life is expected to depend on the electron density at the nucleus. We measured the 7 Be half-life in palladium, tungsten, zirconium and tantalum metals, in order to investigate the influence of the quasi-free electrons in metals on the probability of electron capture. The 7 Be samples were obtained implanting a 4.85 MeV pure radioactive 7 Be ion beam. The 7 Be half-life was determined measuring the 478 keV gamma decay following the electron capture by means of HPGe detectors. In order to reduce systematic errors, we planned to perform independent measurements in three different laboratories: Naples (Italy), Bochum (Germany) and Debrecen (Hungary). On the basis of the first results, we do not find a 7 Be half-life change within the experimental errors of 0.4%.

show abstract

“…Attempts to explain the experimental results in Sendai [1,2,3], in Bochum and Gran Sasso [4,5,6,7,8,9], and in Berlin [10,12,11] are based on:…”

Section: The Experimental Situation and Interpretation Of The Spreadmentioning

confidence: 99%

The role of correlation entropy in nuclear fusion in liquid lithium, indium and mercury

Coraddu

Lissia

Quarati

et al. 2014

J. Phys. G: Nucl. Part. Phys.

View full text Add to dashboard Cite

Abstract. Nuclear fusion cross-sections considerably higher than corresponding theoretical predictions are observed in low-energy experiments with metal matrix targets and accelerated deuteron beams. The cross-section increment is significantly higher for liquid than for solid targets. We propose that the same two-body correlation entropy used in evaluating the metal melting entropy explains the large liquid-solid difference of the effective screening potential that parameterizes the cross-section increment. This approach is applied to the specific case of the 6 Li(d, α) 4 He reaction, whose measured screening potential liquid-solid difference is (235 ± 63) eV. Cross sections in the two metals with the highest two-body correlation entropy (In and Hg) has not been measured yet: increments of the cross sections in liquid relative to the ones in solid metals are estimated with the same procedure.

show abstract

Electron screening in d(d,p)t for deuterated metals and the periodic table

Cited by 89 publications

References 12 publications

The ² H(d,p) ³ H reaction in metallic media at very low energies

The ² H(d,p) ³ H reaction in metallic media at very low energies

New measurement of 7Be half-life in different metallic environments

The role of correlation entropy in nuclear fusion in liquid lithium, indium and mercury

Contact Info

Product

Resources

About

Electron screening in d(d,p)t for deuterated metals and the periodic table

Cited by 89 publications

References 12 publications

The 2 H(d,p) 3 H reaction in metallic media at very low energies

The 2 H(d,p) 3 H reaction in metallic media at very low energies

New measurement of 7Be half-life in different metallic environments

The role of correlation entropy in nuclear fusion in liquid lithium, indium and mercury

Contact Info

Product

Resources

About

The ² H(d,p) ³ H reaction in metallic media at very low energies

The ² H(d,p) ³ H reaction in metallic media at very low energies