-
Effects of a Threshold Resonance
in the DD Reactions
Studied in Metallic Environments
d d +
+
3He + n
3H + p
1 Konrad Czerski
September 14-18, 2015
-
penetration factor
through the Coulomb barrier
E
E
E
EEP GG exp)(
V(r)
- 50 MeV
r
E
... depends on the plasma temperature
T (Sun) = 15 million deg
V(r) = Z1 Z2 e
2
r
Tunnel Effect
2
-
Electron Screening in Nuclear Reactions
V(r)
-50 MeV
r
V(r)
-50 MeV
r
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)
3
-
Experimental Results (HV)
cos1 22PAd
dtot
angular distribution
A2
4
EPL 2001
-
Experimental Results (HV) II
NIC 1998, p. 152
Europhys. Lett. 54 (2001) 449
Similar results:
J. Kasagi et al., J.Phys.Soc.Jap. 71 (2002) 2281
F. Raiola et al., Eur.Phys.J. A13 (2002) 337
F. Raiola et al., Eur.Phys.J. A19 (2004) 283
gas target
metal target
d + d 3He + n
d + d 3H + p
Ue = 25±5 eV U.Greife et al., Z.Phys. A351 (1995) 107
5
-
Experimental (HV) and Theoretical Results
0 20 40 60 80 1000
50
100
150
200
250
300
350
Li
theo
exp
Al
TaPd
Zr
Al
Scre
en
ing
En
erg
y (
eV
)
Atomic Number Z
Li
Zr PdTa
1.0 1.5 2.0 2.5 3.0 3.5 4.00
50
100
150
200
250
300
350
TF
theo
exp
Li
Po
larisa
tio
n S
cre
en
ing
En
erg
y (
eV
)
rs
Ta Pd
Al
Zr
dielectric function theory:
free and bound electron polarization
cohesion screening
Europhys. Lett. 2004, Phys. Rev. C 2008
electron-gas parameter rs
0
3/1
1
4
3
anrs
6
-
UHV Experimental Setup
ECR ion source
analyzing
magnet
electron detector target chamber
mass
spectrometer
I: 10-30 µA
V: 30 kV
V: ~ 1 V
p: 10-11 – 10-10 mbar 7
-
UHV Results
8 200 400 600 8000
20000
40000
60000
80000
Co
un
ts
Electron Energy (eV)
Zr Ue = 497 ± 7 eV
with LN2 cooling
pH2O ~ 5x10-12 mbar
Auger electron spectroscopy
Ue (HV) 300 eV
Ue (theo) 97 eV
EPJ A, 2011
-
Compund Nucleus 4He
9
-
Nuclear Molecule States
Correlation diagram for the valence particle in the nuclear
two-center system
10 r
d + d structure
-
UHV Electron Screening – Resonance Contribution
0 5 10 15 20 25 30
80
85
90
95
100
105
110
Cro
ss S
ection (
arb
. units)
Energy (keV)E
nh
an
ce
me
nt F
acto
r
interference effect
2
Zr
Ue = 130 eV
11
p=20 meV
16 matrix elements Tβα = <2Sα+1LαJ|J
π|2Sβ+1LβJ >
5 10 15 20 25
0.8
1.0
1.2
1.4
1.6
1.8
2.0
exp
screening
screening & resonance
resonance
En
ha
nce
me
nt
Facto
r
Deuteron Energy (keV)
-
eLBRUS: scheme
Accelerator
with Ultra High Vacuum
Nuclear
Power
Nuclear&Medical
Physics
Nanoscopic Material
Modification
Radiospectroscopy
NMR & EPR Laser
Diagnostics
Polymer Physics
Unique combination of research methods of nuclear physics with
methods
of solid-state physics and laser optics for study of the
condensed hard,
soft and biological matter
e Laboratoria
Badawczo-
Rozwojowe
Uniwersytetu
Szczecinskiego
12
-
eLBRUS: realization
13
-
Laboratory of Nuclear and Medical Physics
accelerator with ultra high vacuum
prototype ECR ion source
low emittance , high current,
light ions – a few mA
Dreebit, Dresden, Germany
p = 10 -11 mbar
Equipment:
Electron Auger Spectroscopy
XPS, UPS
scanning pulsed Argon gun – ToF spectr.
mass spectroscopy
PREVAC, Poland
-
Cross Sections @ 1 keV
0 10 20 30 40 50 60
0.6
0.8
1.0
n
pB
ran
ch
ing
Ra
tio
ELAB
(keV)
resonance+direct
Sr
Ta
0 10 20 30 40 50 60
0,0
0,1
0,2
0,3
0,4
pro
ton
ch
an
ne
l (a
2/a
0)
E(keV)
0 10 20 30 40 50 60
0,0
0,2
0,4
0,6
0,8
1,0
a2/a
0 n
eu
tro
n c
ha
nn
el
E(keV)
Sr
Ta
16 transition matrix elements
neutron channel proton channel
branching
ratio
APP B 2014
-
eLBRUS : Dual Fluid Reactor
& chromosome aberrations
-
People
TU Berlin, IFK Berlin U Szczecin K. Czerski K. Czerski
A. Huke N. Targosz
P. Heide A. Kilic
D. Weißbach M. Kaczmarski
A. Kowalska
W. Pereira
TRIUMF, Vancouver HU Berlin G. Ruprecht H. Winter
L. Martin D. Blauth
Electron Screening
17
