deuteron fusion reactions in metallic environments
DESCRIPTION
Deuteron Fusion Reactions in Metallic Environments. K. Czerski Institute of Physics, University of Szczecin. Euratom Workshop Szczecin, 23 . 03 .200 6. Z 1 Z 2 e 2. Z 1 Z 2 e 2. r. r. Z 1 Z 2 e 2. U e =. a. P ( E ). P ( E+ U e ). - PowerPoint PPT PresentationTRANSCRIPT
K. Czerski Institute of Physics, University of Szczecin
Euratom Workshop Szczecin, 23.03.2006
Deuteron Fusion Reactions inMetallic Environments
V(r)
-50 MeV
r
V(r)
-50 MeV
r
Electron Screening in Nuclear Reactions
V(r) = exp (- r /a ) Z1 Z2 e 2
r
Z1 Z2 e 2
r≈ - Ue
R a
screening energy
Ue =Z1 Z2 e 2
a
E
E
E
EEP GG exp)(
s-wave penetration factor
P(E) P(E+Ue)
Experimental Set-Up
200 kV accelerator
TU Berlin
d d +
+
Similar results:J. Kasagi et al., J.Phys.Soc.Jap. 71 (2002) 2281F. Raiola et al., Eur.Phys.J. A13 (2002) 337
gas target
K. Czerski et al., Europhys. Lett. 54 (2001) 449metal targets
d + d 3He + n
d + d 3H + p
Ue = 25±5 eVU.Greife et al., Z.Phys. A351 (1995) 107
Enhanced Electron Screening Effect I
E
U
E
E
E
UEEF eGe
bare
scr
2
1exp
)(
)()(
F(E
)
enhancement factor :
in metallic environments
Ue screening energy
εc(q)
Dielectric Function Theory
v= c= 1 r
e2
self-consistent charge formfactor
z number of bound electronskTF Thomas-Fermi wave number
valence-electron dielectric function
P(q) Lindhard RPA polarizabilityG(q) local field correction
core-electron dielectric function from f-sum rule
qdrqiqqq
qer
r
erV
cv
32
2
3
2
)exp()()(
))((4
)2(
1)()(
)/(1)( 222TFkqzqzq
)()()(1
)()(1)(
qPqGqv
qPqvqv
K. Czerski et al., Europhys. Lett. 68 (2004) 363
Enhanced Electron Screening Effect II
0,0 0,4 0,8 1,2 1,6 2,0
0,0
0,4
0,8
1,2
PdD
(r)
Deuteron-Deuteron Distance (10-10m)
screening function with LFC exponential screening function screening function without LFC
0 20 40 60 80 100
0
50
100
150
200
250
300 exp
theo
polarization
cohesion
Scr
eeni
ng E
nerg
y (
eV)
Atomic Number
Li Be Al Zr Pd Ta
C
D-D Potentialdielectric-function theory
Results
K. Czerski et al., Europhys. Lett. 68 (2004) 363
Comparison of Experimental Results
Proposal I
Experimental:new measurements under ultra-high vacuum conditionslooking for the target material and temperature dependence
Theoretical:improvement of the dielectric-function theorypolarization of deuterons within the crystal lattice
Collaboration
University of Szczecin: Prof. K. Czerski, Prof. A. Bechler, Ż. Wyrwał-Artyszuk
Technical University of Berlin: Prof. P. Heide, Prof. G. von Oppen, Dr. A. Huke
Humboldt University of Berlin: Prof. H. Winter, Dr. M. Busch
cos1 22Pa
d
dtot
Angular Distribution
d + d 3He + n d + d 3H + p
Taa2
Energy Spectra
Suppression of Neutron Channel
16 transition matrix elementss, p und d waves
channel spin S = 0,1,2
experimental results can be explained
if
S = 0
Polarisation von Deuteronen ?
A. Huke, K. Czerski, accepted Eur. Phys. J. A
Proposal II
Experimental:direct measurement of the neutron channelenergy and target material dependence of the effect
Theoretical:search for a theoretical explanation of the deuteron polarization within the crystal lattice
Collaboration
University of Szczecin: Prof. K. Czerski, Prof. R. Fedaruk, Prof. J. Stelmach
Technical University of Berlin: Prof. P. Heide, Dr. A. Huke, L. Martin
Humboldt University of Berlin: Prof. H. Winter, Dr. M. Busch