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RESEARCH INTO LOW ENERGY NUCLEAR REACTIONS IN CATHODE SAMPLE
SOLID WITH PRODUCTION OF EXCESS HEAT, STABLE AND RADIOACTIVE
IMPURITY NUCLIDES.
A.B.Karabut
FSUE LUCH
24 Zheleznodorozhnaya St, Podolsk, Moscow Region, 142100, Russia.
ABSTRACT
Results on measurements of excess heat power, impurity nuclides yield, gamma and X-ray emission in
experiments with high-current glow discharge (GD) in D
2
, Xe and Kr are presented. The cathode samples used in the
experiments were made of Pd, V, Nb, Ta. In experiments with Pd cathode samples in D
2
GD, the recorded excess heat
power amounted to 10 15 W and the estimated efficiency (the output thermal power in relation to the input electric
power) was up to 130 %. Excess heat power up to 5 W, and efficiency up to 150 % was recorded for deuterium pre-
charged Pd cathode samples in Xe and Kr discharges. Production of impurity nuclides with atomic masses less than
and more than that of the cathode material was registered. Considerable deviation from the natural isotopic ratio was
observed for the registered elemental impurities. X-ray emission was measured in H
2
, D
2
, Ar, Xe and Kr GD during the
GD operation and after the GD current switch off (up to several hours afterwards) with the help of thermo-luminescent
detectors (TLD), X-ray film and scintillator detectors with photomultipliers. The recorded energetic spectra of X-ray
emission range 0.5 10 keV. Weak gamma-emission (up to 1,000 events per second) was registered in certain
experimental conditions. The X-ray spectra include both (bands of) the continuum and multiple lines with energies
ranging 0.1 3.0 MeV. The possible mechanism for production of the excess heat power, elemental impurities, gamma
and X- ray emission is also considered.
1. INTRODUCTION
Measurements of the excess heat, isotopic impurities, heavy particles emission and soft X-ray emission in high-
current density glow discharge have been carried out for years. Further experimental evidence is required to elaborate a
reliable theory explaining the phenomena under discussion. The present research is focused on this problem.
2. EXCESS HEAT MEASUREMENTS BY FLOW CALORIMETER
The measurements were carried out using the glow discharge device (GDD) consisting of a water-cooled vacuum
chamber, the cathode and the anode assemblies. The cathode design allowed the placement of the cathode samples
made of various materials on the cooled surface. Three components of the device (the cathode, anode and chamber) had
independent water-cooling channels. Each cooling channel incorporated thermal sensor (at the input and output)
connected differentially and a water flow meter. The device was placed into a thermal insulation package, comprising
the flow calorimeter.
The pulse-periodic electric power supply was used. The thermal (signals from thermal sensor and the flow-meter)
and the electric parameters (the GD current and voltage) were recorded using a data acquisition board. The values
obtained were processed by a computer. The excess heat power P
EH
value was determined by
P
EH
= (P
HC
+ P
HA
+ P
HCh
) - P
el
P
error
where P
el
is the GD input electric power; P
HC
, P
HA
, P
HCh
represent the output heat power carried away by the cooling
water from the cathode, anode and chamber, respectively;
P
error
stands for the complete absolute error of the power
measurement for the given measuring system. Calibration of the measurement system was carried out in the following
way: a water-cooled electric resistive heater wrapped into an insulating package was placed among the thermistors
inside each thermal power measuring channel. The amount of the consumed cooling water corresponded to that inside
the GDD. The resistive heater was powered by a pulse-periodic power supply. The heater electric parameters were
identical to those of the GD. The measured thermal power of the resistive heater was equated to the heater measured
electric power. The calibration relationship was estimated at different values of the input electric power.
The Pd samples used in tests with Xe and Kr GD were not deuterium pre-charged. The measurement system allowed
to record the GD input electric power and the thermal power output by the cooling water with accuracy of 0.6 W at the
absolute value of the electrical power up to 120 W (relative error
0.5%,).
In this set of the experiments the current density did not exceed 100 mA/cm
2
. At such values of the discharge current
in D
2
, a continuous loading of D
2
into Pd ran up to saturation. The experiments were carried out with Pd cathode
samples in D
2
GD, and with deuterium pre-charged Pd cathode samples in Xe and Kr discharges. The amount of the 2
loaded D
2
was estimated by the pressure drop in the chamber. D
2
was periodically supplied into the chamber to
maintain the required pressure. The amount of deuterium loaded into palladium was determined by the volume of the
gas absorbed from the discharge chamber. When saturation was achieved, the value of the D/Pd ratio was close to 1.
Heat measurements were carried out for Pd cathode samples in GD while changing the following parameters: GD
current density, voltage, duration of current pulses, and the time between current pulses (from the power supply). The
absolute value of the excess heat power and thermal efficiency grew with increasing the power input into the discharge
(Fig.1). Relatively high values of the excess heat power, and thermal efficiency, were achieved for deuterium pre-
charged cathode samples in Xe and Cr discharges. No excess heat power production was observed in the cathode
samples made of pure Pd (not deuterium pre-charged) in Xe and Kr discharges (Fig.2a, curve 3).
Two prominent areas can be singled out (strong curve 1 and weak curve 2) representing the excess heat power and
thermal efficiency dependence of the input electric power. The graph (Fig.3) shows that the maximum excess heat
values were recorded at the GD operational voltage ranging 1000 - 1300 V.
Thus, it was experimentally shown, that the Excess Heat power production was determined by two processes: 1)
deuterium should be loaded into the medium of the solid crystal lattice; 2) the crystal lattice should get initial
excitation, so that high-energy long-lived excited levels were created in the cathode solid. These excited conditions
could be created by an additional source (for example by a flow of inert gas ions).
The three-channel system of separate measurements of the output excess heat power (for the anode, cathode and
chamber) allowed to define the structure of the excess heat power output in the GD. Large efficiency values were
achieved in experiments with high relative heat release on the cathode. This data prove that the excess heat power was
produced mainly on the cathode (Fig.2b).
3. REGISTRATION OF IMPURUTY NUCLIDES
Presently, the release of excess heat power is accounted for by 4He production and the on-going reactions of
transmutation accompanied by the impurity nuclides yield. The impurity elements content in the cathode samples were
analyzed before and after the experiments with high-current GDD. The Pd cathode samples were analyzed for
impurities after their exposure to D2 discharge. The cathode samples made of mono-isotopic metals (V, Nb, Ta) were
studied after the exposure to D2 and H2 at the same GD operational regimes. The following methods were used:
secondary ionic mass spectrometry (for Pd samples), and secondary neutral mass spectrometry (for V, Nb, Ta samples).
These techniques were used to analyze the impurity content in the cathode samples material before, and after, the
experiment.
Table 1.
A
Impur.
nuclide
1 scan
10 nm,
content%
2 scan
50 nm,
content,
%
3 scan
700 nm,
content,
%
4 scan
800nm,
content,
%
A
Impur.
nuclide
1 scan
10 nm,
content,
%
2 scan
50 nm,
content,
%
3 scan
700nm,
content,
%
4 scan
800 nm,
content,
%
6
Li
0.075
0.22
0.21
0.16
71
Ga
4.0
4.9
5.6
3.4
7
Li
0.84
0.53
0.45
0.47
72
Ge
5.1
4.4
5.1
6.0
11
B
0.14
0.31
0.18
0.18
75
As
6.2
4.9
7.4
4.7
12
C
0.93
0.63
0.47
0.54
77
Se
3.4
3.9
4.8
4.0
13
C
0.19
0.15
0.05
0.06
78
Se
4.5
3.45
5.8
1.4
20
Ne
0.14
0.27
0.14
0.16
79
Br
3.0
2.4
2.8
42
Ca
0.72
1.14
1.08
0.8
80
Se
4.0
3.4
2.5
2.3
44
Ca
2.0
3.2
3.1
2.6
82
Se
3.4
3.0
3.2
45
Sc
0.74
0.91
0.86
0.8
85
Rb
2.2
3.4
3.3
3.6
46
Ti
0.57
0.72
0.52
0.7
88
Sr
3.1
4.4
4.2
6.0
47
Ti
0.25
0.14
0.31
0.14
90
Zr
2.4
1.5
2.3
5.8
48
Ti
1.1
1.23
1.1
0.66
111
Cd
2.8
3.0
3.0
3.4
52
Cr
0.62
0.41
0.31
0.1
112
Cd
3.4
3.2
4.2
56
Fe
2.9
2.6
3.1
2.7
113
Cd
4.0
1.8
2.8
5.1
57
Fe
5.5
3.25
3.53
3.16
114
Cd
4.7
3.9
3.3
3.6
59
Co
1.0
1.0
1.4
1.5
115
In
2.2
2.5
2.3
66
Zn
0.21
0.43
0.54
1.0
The difference in the content of the impurity elements before, and after, the experiment was defined as storage of the
elements during the experiment. The procedure for determining the impurities by the method of the secondary ion
mass spectrometry included the following stages: (a) removal the upper 1.5nm-thick defect layer by plasma etching, (b)
scanning the first and the second layers in 5nm increments, while determining the content of the impurity nuclides, (c) 3
removal of a layer with the thickness of 700 nm and repeated scanning of the third and fourth layers in 5nm increments
while again determining the content of the impurity nuclides (Fig.4).
Table 2
V H
V D
A
Impur.
nuclide
1 scan
10 nm,
content,
%
2 scan
50 nm,
content,
%
3 scan
700 nm,
content,
%
A
Impur.
nuclide
1 scan
10 nm,
content,
%
2 scan
50 nm,
content,
%
3 scan
700 nm,
content,
%
99Ru
ND
ND
ND
99Ru
0.42
0.11
0.02
102Ru
0.66
0.73
0.4
102Ru
0.74
0.51
0.4
103Rh
0.25
0.14
0.02
103Rh
0.19
0.23
0.34
104Pd
0.16
0.04
0.3
104Pd
0.22
0.2
0.37
106Pd
0.15
0.02
0.02
106Pd
0.29
0.16
0.12
108Pd
0.45
0.04
0.06
108Pd
0.21
0.24
0.12
111Cd
0.05
0.16
0.01
111Cd
0