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Modeling excess heat in NiH. Peter Hagelstein 1 and Irfan Chaudhary 2 1 Massachusetts Institute of Technology 2 University of Engineering and Technology, Lahore. NiH. Before looking at expts…. Excess heat seen in NiH experiments

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modeling excess heat in nih

Modeling excess heat in NiH

Peter Hagelstein1 and Irfan Chaudhary2

1Massachusetts Institute of Technology

2University of Engineering and Technology, Lahore

before looking at expts
Before looking at expts…
  • Excess heat seen in NiH experiments
  • Effect first reported in electrolysis experiments by Mills and Kneizys (1991)
  • Excess heat in gas loading experiments reported by Piantelli et al (1994)
  • NiH is not PdD
  • Differences are important
phase diagram
Phase diagram

Note: 400 Mpa = 3948 atm

x ray diffraction data in electrochemical loading
X-ray diffraction data in electrochemical loading

Juskenas et al, Electrochimica Acta43 1903 (1998)

No evidence for intermediate a values for loadings in the a-b phase region. Observed only is the change in volume occupied by b-phase NiH.

slide9

[100] Displacement of D2 in PdD Supercell Monovacancy

L Dechiaro,

Quantum Espresso

DFT calculation

slide10

Electron density even higher in Ni (which is why H doesn’t load well). But electron density reduced near a vacancy, and can form H2. Ni is closest analog of Pd for H2/D2 formation near vacancy. Expect issues for vacancy creation and HD molecule formation to be similar.

ni phonon modes
Ni phonon modes

D. A. Dimitrov et al Phys. Rev. B60 6204 (1999)

donor receiver model
Donor-receiver model

HD

AZ*

3He

AZ

Phonon mode

Donor system

Receiver system

more p xs with d added
More Pxs with D added

M. R. Swartz, G. M. Verner, and A. H. Frank, Proc. ICCF9 p. 335 (2002).

more issues
More issues
  • HD/3He transition fine for donor
  • Reduced mass smaller than for D2/4He system
  • So tunneling is orders of magnitude larger
  • Deuterium natural abundance is 1/6240 of hydrogen
  • DE = 5.49 MeV, so need to exchange few quanta
take away message
Take away message
  • Excess heat seen in NiH
  • Electrochemical systems, gas systems
  • Harder to load
  • Easier to make vacancies
  • HD formation good
  • Donor-receiver model happy
  • Is some D in H
  • Larger interaction matrix element since Gamow factor smaller
piantelli experiment19
Piantelli experiment

Ni rod:

 10 cm 

  • 9 cm 
  • 0.5 cm diameter

S Focardi, R Habel, and F Piantelli, Il Nuovo Cimento, 107A 163 (1994)

data showing p xs
Data showing Pxs

Input power: 140? W

Excess power: 20 W

1998 piantelli experiment
1998 Piantelli experiment

S Focardi, V Gabbani, V Montalbano, F Piantelli, S Veronesi,

Il Nuovo Cimento 111 1233 (1998)

excitation of the sample
Excitation of the sample

DT1 = 467.4

DT1 = 381.7

Approx:

Pin = 60 W

Pxs = 20 W

pressure composition isotherms
Pressure-composition isotherms
  • NiH is like PdH…

1 atm = 105 Pa

thinking about result
Thinking about result
  • Bulk Ni does not load much (5-20x10-5) near 1 atm
  • Need O(6000 atm) to pressure-load bulk Ni with H2
  • But some loading observed nonetheless in Piantelli expts
  • Number of H atoms absorbed is several times O(3x1021)
  • Number of Ni atoms in sample (1994) is O(4x1023)
  • Loading in Cammarota replication from H2 absorption is NiH0.2
  • Must be (non-bulk) special sites (defects or impurities)
  • But not enough impurities in Cammarota version!
x ray diffraction data in electrochemical loading30
X-ray diffraction data in electrochemical loading

Juskenas et al, Electrochimica Acta43 1903 (1998)

No evidence for intermediate a values for loadings in the a-b phase region. Observed only is the change in volume occupied by b-phase NiH.

diffusion of h
Diffusion of H
  • Diffusion of H in Ni is much slower
  • than in Pd
  • Elevated temperature D in NiH is
  • similar to D in PdD at 300 K

D = D0 e-DE/kT

D0 = 7.04x10-3 cm2/sec

DE = 409 meV

D(300K) = 9.5x10-10 cm2/sec (NiH)

D(300K) = 5.5x10-7 cm2/sec (PdD)

excitation of the sample33
Excitation of the sample

DT1 = 467.4

DT1 = 381.7

H outgassing with

temperature rise

Approx:

Pin = 60 W

Pxs = 20 W

g emission events
g-emission events

S Focardi and F Piantelli, “Produzione de energia e reazioni nucleari in sistemi NiH

a 400 C” (2000)

new elements in miley expts
New elements in Miley expts

G. H. Miley and P. J. Shrestha, Slides presented at ICCF12 (2005).

slide37

Low H loading in NiH gas systems

  • Not enough H for good optical phonon mode
  • NiH systems so far probably work based on acoustic mode excitation
  • Ni then participates strongly in vibrations
  • Coupling of energy through nuclear excited states in Ni
  • Some long-lived ones will have fission decay pathways
  • Lattice-induced fission produces new elements
  • Eats up significant amount of produced energy
wish list for santa
Wish list for Santa
  • Measurements of 3He in gas phase
  • And correlation with energy (is Q-value 5.5 MeV?)
  • Quantitative assay of Ni disintegration products
  • More experiments with HD/3He branch in Pd codep expts
  • Two-laser experiments in Ni to shed light on acoustic mode operation
  • Like to have NiX alloy with lower electron density
take away message39
Take away message
  • NiH excess heat discovered by Mills and Kneizys (1991)
  • Gas loaded excess heat by Piantelli group (1994)
  • H doesn’t load well in Ni
  • Indirect evidence for vacancy generation in Piantelli experiment
  • Excess power stimulated by H flux
  • High temperature operation favors 3He diffusion
  • Excess heat stays on after flux initiation (consistent with nuclear energy going into acoustic phonon modes
  • Acoustic mode operation connected with transmutation