Energetic Charged Particle Emission from the Hydrogen Loaded Pd and Ti Cathodes and its Enhancement by a He-4 Implantation A.G. Lipson* +, A.S. Roussetski**, G.H. Miley*, B.F, Lyakhov + *University of Illinois at Urbana-Champaign, Urbana, IL + Institute of Physical Chemistry, The Russian Academy of Sciences ** Lebedev Physics Institute The Russian Academy of Sciences
Introduction I Detection of energetic nuclear products easily distinguished from the Background/cosmic emissions would be a strong evidence for LENR existence in non-equilibrium metal deuterides. Charged particles from DD-reaction (3.0 MeV p and 1.0 MeV t) show very low intensity and appear at such energy range where the background counts are typically nonnegligible.
Introduction II First detection of particles E > 8.0 MeV in Au/Pd/PdO:D(H)x during exothermic D/Hdesorption: A.G. Lipson et al., Bull. Lebedev Phys. Inst., No.10, 22(2001). Spectra of alpha particles in electrolysis and GD are similar to that obtained from powerful laser irradiation of Ti hydrides/deuteride target.
Objectives Search of energetic charged particles (ECP) signatures using SSB and CR-39 track detectors techniques in D(H)-loaded metals with a large hydrogen solubility. Confirmation of LENR occurrence by comparison of ECP emissions from Pd/Ti with the detector s background response and runs with other metals. Study of He-4 implantation effect on the ECP emission parameters during and after electrolysis of Pd cathode. Search for enhancement of ECP yield?
Detection technique I Si-surface barrier detectors (ORTEC) of various efficiency calibrated with 241 Am alphasource operated in vacuum 10-3 -10-6 torr: SSB(1): S=100 mm 2, SSB(2): S=900 mm 2 (d=10-20 mm). de-e SSB detector pair (de->20 μm, E->100 μm, time gate Δτ = 20 ns) in air at ambient condition: 2- dimensional spectra for particle identification
Detection technique II CR-39 detectors (purified: < 20 track/cm 2 ) Landauer (USA), S=2 x 1 cm 2 attached to cathode in electrolysis; Various metal foils used as a shielding (11-66 μm Al, 25-50 μm Cu) allow identify charged particle accordingly to stopping range. Accelerator p/α calibration of detectors CR-39 Etching: 6MNaOH, t= 70 C, τ=7 hr: Foreground and Background detectors were etched simultaneously.
Samples Electrochemical loading of Ti, Pd/PdO and Au/Pd/PdO:D x (1M-Li 2 SO 4 /H 2 O; 1M NaOD/D 2 O; j=20 ma/cm 2 ) heterostructure (40-60 μm thick): in-situ during electrolysis and/or D/H-desorption @ T=300 K (SSB measurements only after electrolysis + CR-39). Alumina/Pd(600nm), Glass/Pd(250 nm) thin film cathodes electrolysis: CR-39 in-situ measurements (1MLi 2 SO 4 /H 2 O, j=10 ma/cm 2 ). Ti, and Pd/PdO foils implantation with He-4 ions using He-gun: total fluence Φ = 2x10 16 4 He/cm 2,E He = 20 kev (R He ~ 20-30 nm)
Typical charged particle background in vacuum (t=8 days in a row), A.G. Lipson et al., Fusion Tech, 38, 238 (2000). Au/Pd/PdO pristine sample is in front of the SSB-1 (d=15 mm) 16 14 12 Au/Pd/PdO-pristine Background, p=10-6 torr, SSB: S=100 mm 2 10 Count 8 6 Radon 4 2 0 0 1 2 3 4 5 6 7 8 9 10 11 12 E nergy, [M ev ]
Au/Pd/PdO:Dx after the electrolytic D-loading. Sample is in front of Detector (d=15mm). Foreground run, SSB detector efficiency 3.3 % 8 Au/PdO:D x, spontaneous D-desorption: T=300K, p=10-6 torr, SSB:S=100 m m 2, t=133,000 s 6 Count 4 Radon 2 p(d+d)??? 0 0 2 4 6 8 10 12 Energy, [MeV]
Weak spontaneous DD-proton emission from Au/Pd/PdO:D x in vacuum (after electrolytic D-loading) SSB-1 data 0.30 Au/Pd/PdO:Dx(FG) - Au/Pd/PdO:Hx(BG) in vacuum, SSB: S=100 mm 2, ε = 3.3 % Στ(BG) = Στ(FG) = 40.0 hr 0.25 Count, [cph] 0.20 0.15 0.10 0.05 0.00-0.05-0.10 <n p > = (4.0+/-1.0)x10-3 p/s in 4π ster. 0 1 2 3 4 5 6 Energy, [MeV]
Large area high efficiency SSB-2 detector: S=900 mm 2, ε =12.0 %. Foreground run. The counts with E > 8.0 MeV are collected for a shorter time than that with SSB-1.
de/e Background spectra of charged particles from pristine Au/Pd/PdO sample: Στ = 500 hr. The sample is in front of de detector (d=10 mm). de/e Au/Pd/PdO Background run (de/e TDC 750-920 ch, gate 20 ns) 2200 Au/Pd/PdO Background run de, [channel] 1750 1300 850 Alpha energy(5.2-14.0 MeV) Proton energy(1.3-3.5 MeV) 400-50 -50 400 850 1300 1750 2200 E, [channel]
de/e (SSB: de=20μm, E=100 μm) 2-dimensional spectra of charged particles from Au/Pd/PdO:D x (after electrolysis): Στ = 550 hr.; <N α >= (6.4±1.2)x10-4 [s -1 ] in 4π ster. 2000 1500 de/e TDC 750-920 ch 5.5 MeV de/e two dimensional spectra of charged particles emitted from Au/Pd/PdO:Dx; Στ = 500 hr. de-e time gate = 20 ns de, [channel] 1000 500 1.4 MeV 7.0 MeV E(α) 8.0 MeV 10.0 MeV 1.75 MeV 2.0 MeV 2.5 MeV E(p) 12.0 MeV 3.0 MeV 14.0 MeV 3.5 MeV 0 0 500 1000 1500 2000 E, [channel]
Alpha-sources and Cyclotron alpha beam calibration (2-30 MeV) of CR-39 Alpha calibration curves for Fukuvi and Landauer CR-39 detectors 13 12 11 Track diameter, mcm 10 9 8 7 Fukuvi Landauer 6 5 0 5 10 15 20 25 30 Ea, MeV
Tracks from 11.0 MeV α-beam @ normal direction with respect to CR-39 (Landauer) target: image area S= 0.12x0.09 mm
Proton Calibration with Van-DeGraaf accelerator (0.6-3.0 MeV) *calibration was sponsored by Lattice Energy LLC Proton calibration curves for Landuer and Fukuvi CR-39 detectors Track diameter, mcm 9 8.5 8 7.5 7 6.5 6 5.5 5 4.5 0.5 1 1.5 2 2.5 3 3.5 Ep, MeV Landauer CR-39 Fukuvi CR-39
Tracks from 2.5 MeV p-beam @ normal direction with respect to the CR-39 (Landauer) target: image area S= 0.12x0.09 mm
CR-39 data on EPC emissions (8<E α < 16 MeV) in Au/Pd/PdO:Dx (after electrolytic D-loading): <N α > = (5.6 ± 0.5)x10-4 [s -1 -cm -2 ] 4π ster. Compare with de/e 40 35 Au/Pd/PdO:Dx (40 μ m) t=170 hr, P=80 g St. steel (100 μ m), t=275 hr., P=200 g Cu (50 μ m), t=275 hr., P=200 g Al (50 μ m), t=275 hr., P=200 g α 30 Number of tracks 25 20 15 10 p/d? Radon 5 0 5 6 7 8 Track diameter, [μ m]
Open and Cu-shielded CR-39 Background Data
Histograms of track distributions with open CR- 39 detectors: Pd/Al 2 O 3 cathode in-situ electrolysis
Histograms of track distributions with 25 μm Cushielded CR-39 detectors: Pd/Alumina cathode, in-situ electrolysis.
Foreground alpha energy distributions for open and Cu-shielded CR-39 detectors: Splitting of alpha peak in shielded CR-39 detector: Alpha track energy dis tributio ns fo r Fo regro und CR- 39 (Pd/Alumina electrolysis) 30 25 open CR-39 25 mcm Cu/CR- 39 20 15 10 5 0 0 5 10 15 20 25 Alpha Energy, [MeV]
Background Alpha energy distributions for open and 25 μm Cu shielded CR-39 detectors 15 Alpha track energy distribution for Background CR-39 (Pd/Alumina electrolysis) Number of count 12 9 6 open CR-39(bgr) 25 mcm Cu/CR-39(bgr) 3 0 0 5 10 15 20 25 Alpha energy, [MeV]
Possible Alpha spectrum with Background subtracting Rough Reconstruction of alpha spectrum from CR-39 data 24 Number of counts 18 12 6 0 6 9 12 15 18 E, [MeV]
Electrolysis and posteffect with a double Pd/PdO-Pd/PdO:He cathode
Typical Background in 1M-Li 2 SO 4 /H 2 O electrolyte: CR-39 (Landauer) area S=120x90 μm 2
Comparison of ECP emissions from Pd:He and Pd sides of the cathode (with the background subtracting): Enhancement: k α = 3.5, k p =2.0 Track density, [cm -2 ] 60 50 40 30 20 10 Pd/He side electrolysis Pd side electrolysis 0 6 7 8 9 10 11 Track diameter, [μm]
Group of energetic alphas (d=7.2-7.4 μm): Pd/PdO:He electrolysis: 100x100 μm 2 spot (negative image)
Double Ti:He/Ti cathode data (with the Background subtracting), Enhancement: k α = 3.0, k p =8.0 35 30 Ti/He side electrolysis Ti side electrolysis Track density, [cm -2 ] 25 20 15 10 5 0 6 7 8 9 10 11 Track diameter, [μm ]
Comparison of ECP from Pd/PdO:He and Pd/PdO sides during exothermic H-desorption, t=5.0 hr.
Conclusions I Statistically significant number of energetic alphas in the range of 9-16 MeV was detected both with SSB and CR-39 track detectors techniques. Energetic alpha-particles accompanied by 1.7/2.8 MeV protons/deuterons are detected only in hydrogen/deuterium loaded metallic targets with a large affinity to hydrogen (Ti and Pd).
Conclusions II No ECP emissions were found either in the cosmic Background or from the materials with a low hydrogen solubility: Cu, Al, St. steel, Al 2 O 3 (electrolysis), Ta(GD). ECP is a surface phenomenon, independent of sample thickness. (proof that it is not induced by Background cosmic rays). ECP emissions in Pd and Ti could be enhanced by He-4 ion implantation into a near-surface layer.
Possible mechanism speculations Applied energy focusing/concentration in some specific lattice sites near surface (the sites of a high internal strain?). Coherent energy transfer from DD-reaction sites to the light nuclei (P.L. Hagelstein). Effective acceleration of these nuclei (p, d and 4 He) by intratomic electric fields. ECP emissions suggest anomalous energy release via the active lattice sites of nonequilibrium metal deuterides/hydrides
Further Information: Dr. Andrei G. Lipson, UIUC, Visiting Research Professor: lipson@uiuc edu 1. A.G. Lipson, A.S. Roussetski, A. Takahashi and J. Kasagi: Observation of long-range alpha-particles du ring deuterium/hydrogen desorption from Au/Pd/PdO:D(H) heterostructure, Bulletin of the Lebedev Physical Institute (Russian Academy of Sciences), #10, 22-29 (2001). 2. A.G. Lipson, G.H. Miley and A.S. Roussetski, Energetic alpha and proton emissions on the electrolysis of thin-pd films, Trans. Amer. Nuclear. Soc., 88, 638-641, (2003). 3. A.G. Lipson, A.S. Roussetski, G.H. Miley and E.I Saunin, Phenomenon of an energetic charged particle emission from Hydrogen/deuterium loaded metals, Proc. ICCF-10, 24-30 August, Cambridge, MA, 2003