Some Dynamitron electron accelerators are reported to use 5 MeV as acceleration voltage and produce electron currents as high as 160 milliamperes. Each electron in the accelerator can be expected to produce a gamma ray photon. Since an “ampere” of electric current involves 6 x 10¹⁸ electrons per second, 450 microamperes in the electron accelerator at NASA’s Glenn Research Center is able to produce about 10¹⁵ gammas per second. An earlier post, however, indicated that over 10²⁴ gammas per second per cm³ might be required for a LCF type of system that produces 100 watts/cm³. A 10 kW system would need to irradiate 100 cm³.

NASA’s LCF work seems to have followed that of others from 2001 to 2012, listed in References 1-9 in “Investigation of Neutron Generation Upon Irradiation of Deuterated Crystalline Structures with an Electron Beam,” by O.D. Dalkarov et al., Physics of Atomic Nuclei, vol. 84, no. 2, pages 109-114, 2021. Also, see similar work reported in “Synthesis of Chemical Elements and Solid Structures in Atomic-Nuclear Reactions in Dense Gas-Metal Systems Irradiated by Gamma Rays,” Chapter 3 by Roland Wisniewski in “Principles and Applications in Nuclear Engineering – Radiation Effects, Thermal Hydraulics, Radionuclide Migration in the Environment,” edited by Rehab O. Abdel Rahman, IntechOpen, 2018. These have not referenced the original work of Chadwick and Goldhaber in “The Nuclear Photoelectric Effect,” Proceedings of the Royal Society, vol. A151, pages 479-493, 1935.

Quote from NEPS*NewEnergy

can be expected to produce a gamma ray photon

I continue to see if gamma photon can be reflected like with a mirror. If not, will a crystal structure guide... What advances in nano tech for gamma control beyond new lightweight flexible gamma shield?

Anyways... this is purely a layman's unclear ponderings.

If a gamma ray photon somehow returns to the reaction locations?

Perhaps off topic

Prismatoid light guide array for enhanced gamma ray localization in PET: a Monte Carlo simulation study of scintillation photon transport

Andy LaBella¹, Wei Zhao², Rick Lubinsky² and Amir H Goldan^2,3 Published 11 September 2020 • © 2020 Institute of Physics and Engineering in Medicine

Physics in Medicine & Biology, Volume 65, Number 18

Citation Andy LaBella et al 2020 Phys. Med. Biol. 65 18LT01

Also

Collimated Ultrabright Gamma Rays from Electron

Wiggling Along a Petawatt Laser-Irradiated Wire

in the QED Regime

https://www.pnas.org › 9911.full.pdf

Collimated ultrabright gamma rays from electron wiggling along a petawatt laser-irradiated wire in the QED regime - PNAS

by WM Wanga · 2018 · Cited by 20

Wei-Min Wanga,b,1, Zheng-Ming Shengc,d,e,f,g, Paul Gibbonh,i, Li-Ming Chena,f, Yu-Tong Lia,f,j,1, and Jie Zhangd,e,f,1a Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China; bBeijing Advanced

Innovation Center for Imaging Technology, Department of Physics, Capital Normal University, Beijing 100048, China; cScottish Universities Physics Alliance, Department of Physics, University of Strathclyde, Glasgow G4 0NG, United Kingdom; dKey Laboratory for Laser Plasmas, Ministry of Education, Shanghai Jiao Tong University, Shanghai 200240, China; eSchool of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China; f Collaborative Innovation Center of Inertial Fusion Sciences and Applications, Shanghai Jiao Tong University, Shanghai 200240, China; gTsung-Dao Lee Institute, Shanghai Jiao Tong University, Shanghai 200240, China; hForschungzentrum Julich GmbH, Institute for Advanced Simulation, J ¨ ulich Supercomputing Centre, D-52425 ¨

Julich, Germany; ¨iCentre for Mathematical Plasma Astrophysics, Katholieke Universiteit Leuven, 3000 Leuven, Belgium; and jSchool of Physical Sciences,

University of Chinese Academy of Sciences, Beijing 100049, China

Contributed by Jie Zhang, August 21, 2018 (sent for review June 6, 2018; reviewed by Yuelin Li and Stefan Weber)

Even though high-quality X- and gamma rays with photon energy below mega-electron volt (MeV) are available from large-scale X-ray free electron lasers and synchrotron radiation facilities, it remains a great challenge to generate bright gamma rays over 10 MeV. Recently, gamma rays with energies up to the MeV level

were observed in Compton scattering experiments based on laser wakefield accelerators, but the yield efficiency was as low as 10−6, owing to low charge of the electron beam. Here, we propose a scheme to efficiently generate gamma rays of hundreds of MeV from submicrometer wires irradiated by petawatt lasers, where electron accelerating and wiggling are achieved simultaneously. The wiggling is caused by the quasistatic electric and

magnetic fields induced around the wire surface, and these are so high that even quantum electrodynamics (QED) effects become significant for gamma-ray generation, although the driving lasers are only at the petawatt level. Our full 3D simulations show that

directional, ultrabright gamma rays are generated, containing 1012 photons between 5 and 500 MeV within a 10-fs duration. The brilliance, up to 1027 photons s−1 mrad−2 mm−2 per 0.1% bandwidth at an average photon energy of 20 MeV, is second only to X-ray free electron lasers, while the photon energy is 3 orders of magnitude higher than the latter. In addition, the gamma ray yield

efficiency approaches 10%—that is, 5 orders of magnitude higher than the Compton scattering based on laser wakefield accelerators. Such high-energy, ultrabright, femtosecond-duration gamma rays may find applications in nuclear photonics, radiotherapy, and

laboratory astrophysics.

Quote from Gregory Byron Goble

Such high-energy, ultrabright, femtosecond-duration gamma rays may find applications in nuclear photonics, radiotherapy, and

laboratory astrophysics.

Military only....

WRT the last two posts (323-324), it should be noted that electron beams can be used to produce gamma rays, and this is standard practice in many laboratories. NASA is using this method to produce gamma rays. The gammas are used to dissociate deuterium. It should also be noted that gamma rays are absorbed in materials by well-known processes.

Recent supportive comment on the web about “Bridging the Gaps: An Anthology on Nuclear Cold Fusion”: "Excellent overview of the field of LENR, this book includes the benefits of LENR technology, how to build a demonstration and many good points on a cathode design. It also includes a generator design as well as the background theory. Everyone in technology should have this book. The author has done a great job of bring all aspects of this field together."

In post #473 in another thread regarding LCF being developed by NASA GRC, Gregory Byron Smith, or Dr. Forsbacka, has indicated that, while their probability calculations are high, GEC has developed the technology to an advanced degree. Thus, the value of the cross section for (d,d) fusion needs to be looked at in greater detail. The cross section for fusion from 120 keV deuterons (10^-5 barn or 10^-29 cm²) mentioned in the above posts # 304-305 came from a graph in the paper, “NASA GRC Hosts Lattice Confinement Fusion Virtual Workshop”. But, this value appears to be too low. Cross section graphs, e.g., for hot fusion, indicate that the cross section for fusion from 120 keV deuterons should probably be between 0.02 and 0.5 barn (ref. pgs. 19-20 in "Plasmas and Controlled Fusion," by Rose and Clark, MIT, 1961 and pg. 21 in "Fusion Energy Conversion" by Miley, ANS, 1976).

Assume that the cross section for the second LCF step involving d,d fusion is 0.02-0.5 barn, or about 10^-25 cm² . In the second step of the process, about half of the neutrons, therefore, might be expected to be able to cause fusion. A 100 watt/cm³ system would need to produce about 1.8x10¹⁴ fusion reactions/sec/cm³. The number of neutrons that would be required for the second step is expected to be twice this, or 4 x 10¹⁴ neutrons. The number of gamma rays required for the first step of the LCF process is expected to be 10⁴ times this, or 4 x 10¹⁸ gamma rays, each greater than 2.22 MeV. A 10 kW system would need to have a cathode composed of 100 cm³.

The above post indicates that, in order to produce 100 watts/cm³, the first LCF step might need to produce 4 x 10¹⁸ gamma rays/second/cm³, each greater than 2.22 MeV. Since 1 MeV = 1.6 x 10^-13 joule, all of the gamma rays would total 1.4 x 10⁶ joule/second or 1.4 Megawatts. Each electron in the accelerator may be able to produce a gamma photon. An “ampere” of electric current involves 6 x 10¹⁸ electrons per second; and, 4 x 10¹⁸ electrons is about 0.7 amperes. If the voltage of the accelerator were 2.22 MeV, then it would consume about 1.6 Megawatts. A 10 kW system would need to irradiate 100 cm³.

Gamma emissions from LENR?

The energy future

Still looking

Nanoparticles as multimodal photon transducers of ionizing radiation - PMC

by EC Pratt · 2018 · Cited by 39 — a, gamma and visible photon sources are generally considered the excitation mechanisms of NPs by ionizing radiation that produces visible light ...

How we created a mini 'gamma ray burst' in the lab for the first time

Jan 15, 2018 — Gamma ray bursts, intense explosions of light, are the brightest events ever observed in the universe – lasting no longer than seconds or ...

Giant photon bunching, superradiant pulse emission and excitation trapping in quantum-dot nanolasers

Frank Jahnke, Christopher Gies, …Sven Höfling

Nature Communications volume 7, Article number: 11540 (2016)

Giant photon bunching, superradiant pulse emission and excitation trapping in quantum-dot nanolasers - Nature Communications

Classical light sources are characterized by their intensity and coherence, whereas quantum light sources are described by photon correlations. Here, the…

www.nature.com

Introduction

• Thermal radiation is found in the uncorrelated spontaneous recombination of independent emitters. Quantum mechanically, this type of light can be distinguished from coherent (above threshold) laser emission or the more exotic nonclassical light states using the second-order photon correlation function, . The latter is two for thermal light, one for coherent emission, and zero for a single-photon source. Despite being widely known1, the experimental demonstration of second-order photon correlations changing from two to one in the threshold transition of a laser was only recently possible in semiconductor nanolasers2 due to the required high-time resolution in connection with the fast decay of photon correlations.
• Investigating the connection between the emission process and photon correlations is even more appealing for superradiance. The latter results from a collective emission process, on the basis of a correlated state of the active material, which is spontaneously established via exchange of photons between the emitters.
• Despite being an extensively studied phenomenon3,4 observed in a variety of systems, including semiconductor quantum dots5,6, practically all demonstrations of superradiance so far rely on macroscopic properties: changes of the time-resolved intensity or linewidth of the emitted radiation.
• Most prominent is the transition of the time dynamics from the exponential decay of independent emitters to superradiant pulse emission as a result of collective-emitter decay3, although most experiments resort to decay-time changes as function of the emitter number. The recent interest in superradiance of superconducting qubits7, trapped atoms8 and semiconductor magneto-plasmas9 was driven by the possibility to study directly the correlated state of the active material.
• In ref. 7, the limit of two emitters has been realized with superconducting qubits. Their entanglement was shown to be the origin for superradiant emission. For an ensemble of entangled emitters, the connection between superradiance and photon correlations has been analyzed in ref. 10. In case of many trapped atoms, their correlated state was used to demonstrate superradiant laser action with ultranarrow linewidth8. By influencing the self-organization of dipoles in a semiconductor magneto-plasma9, superradiant pulse emission was enabled or destroyed.

Also

• Our system represents the solid-state analogue to trapped atoms in an optical or microwave cavity. We use semiconductor quantum-dot emitters, which act as artificial atoms with discrete emission lines. The emitters are embedded in an optical resonator. The system is designed as a monolithic laser device with a miniaturization driven to the level where the spatial dimensions of the resonator approach the light wavelength. In this strongly reduced mode volume, only a small number of emitters is resonantly coupled to the optical mode. As such, our investigations carry recent studies on fundamental quantum–optical systems over to highly miniaturized nanolaser devices. Semiconductor cavity-quantum electrodynamics (QED) lasers have been used to demonstrate coherent emission with strongly reduced laser threshold14,15 and lasing in the strong coupling regime16. So far, cavity-QED laser properties have not been related to superradiance of the active material.
• The central finding is that our system does not behave like a conventional laser. We have identified three independent signatures of dominating inter-emitter coupling, which determine the emission properties below threshold and in the threshold region for pulsed optical pump excitation: superradiant pulse emission with a temporal duration more than one order of magnitude faster than the spontaneous lifetime of individual emitters, giant photon bunching in the second-order photon correlation function strongly exceeding the value of two for thermal light, and excitation trapping suppressing the emission by almost two orders of magnitude as long as the correlations between the emitters are present. All three signatures are

With regard to the last four posts, please note, instead, that NASA/GRC has indicated that they are using their Dynamitron electron acceleration to produce gamma rays for the first step in the LCF process. The upper current level of these machines appears to be about 50-160 milliamps. This is a much lower current than 0.7 ampere mentioned in post #329.

Quote from NEPS*NewEnergy

NASA/GRC has indicated that they are using their Dynamitron electron acceleration to produce gamma rays

Those lovely gammas...

Daydreaming

If gammas were emitted from a nano cavity adding their energetics instead. So I keep looking. Short lived... perhaps difficult to detect. Studying the works of Alan and Russ. Also looking at recent nano physics discoveries... Might they be unlocking the secrets of gamma creation?

Alan Smith  Russ George

At Atom Ecology

Might gammas be produced in a solid state CMNS core without resorting to a Dynamitron? Perhaps a nano dynamitron accelerates electrons or something else does... like split second nano superconductivite conditions come and go.

What can you surmise from your gammas?

gamma Archives - Atom Ecology

Lovely Gammas, like bird songs in the morning

Along with this prodigious heat, the cold fusion reactions in my unique atom-ecology revealed themselves with lovely gamma rays that my multiple gamma instruments captured en mass and in finely resolved spectroscopic detail. At first, the gammas were seen in an array of state of the art Geiger Mueller detectors and were astonishing for synchronizing massive emissions with cycles of the solar day. Every day at the same time for a period while the sun passed overhead the lovely gamma rays did dance (see image below). Some nights when the sun’s rays were shielded by the Earth similar bursts of gammas lasting minutes to hours synchronized with unknown cosmic rays. Don’t be afraid of these gamma rays, our instruments are incredibly sensitive. In practical applications, the gammas will never reach a cm distance from their place of birth.

Lovely Cold Fusion Gamma Rays appear as a steady flux with peaks that are synchronous with the position of the sun in a few morning hours each day, low peaks were cloudy or rainy days. Note the steady-state level is nearly 10X background (the low dips). At the very least this technique becomes a functional fantastic new solar spectroscope able to see here-to-fore unknown solar rays. The mysterious rays trigger a cascade of cold fusions. Click to read more.

What’s next

"Making Cold Fusion Gammas"

Nothing Compares To Being At The Lab Bench - Atom Ecology

May 8, 2018 — Making Cold Fusion Gammas. The Geiger Counter data shown at the top of this post is very RAW

From Atom Ecology

A cautionary or worried piece of advice has come my way.

I wouldn’t rave on too much about those “lovely gammas” if I were you The hot fusion priests may use them as a fall-back position and say “OK, so some forms of cold fusion do work but the gammas make them too dangerous, elaborate or expensive to use”.

(With that, they would be ignoring the neutrons from the DT reaction which hot fusion is still hoping to use but, hey, this is the “post truth” era, remember?).” - end quotes

Quote from The paper

Our system represents the solid-state analogue to trapped atoms in an optical or microwave cavity. We use semiconductor quantum-dot emitters, which act as artificial atoms with discrete emission lines. The emitters are embedded in an optical resonator. The system is designed as a monolithic laser device with a miniaturization driven to the level where the spatial dimensions of the resonator approach the light wavelength.