Lattice confinement fusion

Type of nuclear fusion

Lattice confinement fusion (LCF) is a type of nuclear fusion in which deuteron-saturated metals are exposed to gamma radiation or ion beams avoiding the confined high-temperature plasmas used in other methods of fusion.[1][2]

## History

[edit]

In 2020, a team of NASA researchers seeking a new energy source for deep-space exploration missions published the first paper describing a method for triggering nuclear fusion in the space between the atoms of a metal solid, an example of screened fusion.[3] The experiments did not produce self-sustaining reactions, and the electron source itself was energetically expensive.[1]

## Technique

[edit]

The reaction is fueled with deuterium, a widely available non-radioactive hydrogen isotope composed of one proton, one neutron, and one electron. The deuterium is confined in the space between the atoms of a metal solid such as erbium or titanium. Erbium can indefinitely maintain 1023 cm−3 deuterium atoms (deuterons) at room temperature. The deuteron-saturated metal forms an overall neutral plasma. [dubious - discuss] The electron density of the metal reduces the likelihood that two deuterium nuclei will repel each other as they get closer together.[1]

A dynamitron electron-beam accelerator generates an electron beam that hits a tantalum target and produces gamma rays, irradiating titanium deuteride or erbium deuteride. A gamma ray of about 2.2 megaelectron volts (MeV) strikes a deuteron and splits it into proton and neutron. The neutron collides with another deuteron. This second, energetic deuteron can experience screened fusion or a stripping reaction.[1]

Although the lattice is notionally at room temperature, LCF creates an energetic environment inside the lattice where individual atoms achieve fusion-level energies.[3] Heated regions are created at the micrometer scale.

### Screened fusion

[edit]

The energetic deuteron fuses with another deuteron, yielding either a 3helium nucleus and a neutron or a 3hydrogen nucleus and a proton. These fusion products may fuse with other deuterons, creating an alpha particle, or with another 3helium or 3hydrogen nucleus. Each releases energy, continuing the process.[1]

### Stripping reaction

[edit]

In a stripping reaction, the metal strips a neutron from accelerated deuteron and fuses it with the metal, yielding a different isotope of the metal.[1] If the produced metal isotope is radioactive, it may decay into another element, releasing energy in the form of ionizing radiation in the process.

### Palladium-silver

[edit]

A related technique pumps deuterium gas through the wall of a palladium-silver alloy tubing. The palladium is electrolytically loaded with deuterium. In some experiments this produces fast neutrons that trigger further reactions.[1] Other experimenters (Fralick et al.) also made claims of anomalous heat produced by this system.

## Comparison to other fusion techniques

[edit]

Pyroelectric fusion has previously been observed in erbium hydrides. A high-energy beam of deuterium ions generated by pyroelectric crystals was directed at a stationary, room-temperature ErD2 or ErT2 target, and fusion was observed.[2]

In previous fusion research, such as inertial confinement fusion (ICF), fuel such as the rarer tritium is subjected to high pressure for a nano-second interval, triggering fusion. In magnetic confinement fusion (MCF), the fuel is heated in a plasma to temperatures much higher than those at the center of the Sun. In LCF, conditions sufficient for fusion are created in a metal lattice that is held at ambient temperature during exposure to high-energy photons.[3] ICF devices momentarily reach densities of 1026 cc−1, while MCF devices momentarily achieve 1014.

Lattice confinement fusion requires energetic deuterons and is therefore not cold fusion.[1]

## See also

[edit]

* Inertial confinement fusion
* Magnetized target fusion
* Pyroelectric fusion

## References

[edit]

1. ^ a b c d e f g h Baramsai, Bayardadrakh; Benyo, Theresa; Forsley, Lawrence; Steinetz, Bruce (February 27, 2022). "NASA's New Shortcut to Fusion Power". IEEE Spectrum.
2. ^ a b Steinetz, Bruce M.; Benyo, Theresa L.; Chait, Arnon; Hendricks, Robert C.; Forsley, Lawrence P.; Baramsai, Bayarbadrakh; Ugorowski, Philip B.; Becks, Michael D.; Pines, Vladimir; Pines, Marianna; Martin, Richard E.; Penney, Nicholas; Fralick, Gustave C.; Sandifer, Carl E. (April 20, 2020). "Novel nuclear reactions observed in bremsstrahlung-irradiated deuterated metals". Physical Review C. 101 (4): 044610. Bibcode:2020PhRvC.101d4610S. doi:10.1103/physrevc.101.044610. S2CID 219083603 - via APS.
3. ^ a b c "Lattice Confinement Fusion". NASA Glenn Research Center. Retrieved March 1, 2022. This article incorporates text from this source, which is in the public domain.

* v
* t
* e

Fusion power, processes and devices

Core topics|

| Nuclear fusion|

* Burning plasma
* Timeline
* List of experiments
* List of technologies
* Commercial
* Aneutronic

|

* Nuclear power
* Nuclear reactor
* Atomic nucleus
* Fusion energy gain factor
* Lawson criterion
* Magnetohydrodynamics
* Neutron
* Plasma

Processes,
methods|

| Confinement
type|

| Gravitational|

* Alpha process
* Triple-alpha process
* CNO cycle
* Helium flash
* Nova

* remnants

* Proton–proton chain
* Carbon-burning
* Lithium burning
* Neon-burning
* Oxygen-burning
* Silicon-burning
* R-process
* S-process

|

Magnetic|

* Field-reversed configuration
* Levitated dipole
* Magnetic mirror
* Bumpy torus
* Pinch
* Dense plasma focus
* Reversed field
* Theta
* Zeta
* Stellarator
* Tokamak
* Spherical
* Spheromak
* Dynomak
* Toroidal solenoid

Magneto-inertial|

* Magnetized liner
* Magnetized target

Inertial|

* Bubble (acoustic)
* Laser-driven
* Ion-driven

Electrostatic|

* Fusor
* Polywell

Other forms|

* Colliding beam
* Migma
* Metal lattice
* Muon-catalyzed
* Pyroelectric

Devices,
experiments|

| Magnetic
confinement|

| Tokamak|

| International|

* ITER
* DEMO
* PROTO

|

Americas|

* STOR-M
* Alcator C-Mod
* ARC
* SPARC
* DIII-D
* Electric Tokamak
* LTX
* NSTX
* PLT
* TFTR
* Pegasus
* Riggatron
* SSPX
* ETE
* TCABR
* Novillo [es]

Asia,
Oceania|

* CFETR
* EAST
* HT-7
* HH70
* HL-2A
* HL-2M
* SUNIST
* ADITYA
* SST-1
* JT-60
* QUEST [ja]
* GLAST
* KSTAR
* TT-1

Europe|

* JET
* COMPASS
* GOLEM [cs]
* TFR
* WEST
* ASDEX Upgrade
* TEXTOR
* DTT
* FTU
* IGNITOR
* ISTTOK
* T-15
* TCV
* MAST-U
* START
* STEP

Stellarator|

| Americas|

* CNT
* CTH
* HIDRA
* HSX
* Model C
* NCSX
* SCR-1

|

Asia,
Oceania|

* H-1NF
* Heliotron J
* LHD

Europe|

* WEGA
* Wendelstein 7-AS
* Wendelstein 7-X
* TJ-II
* Uragan-2M
* Uragan-3M [uk]

Pinch|

* Perhapsatron
* Sceptre
* ZETA

RFP|

* RFX
* MST

Mirror|

* GDT
* Astron
* Lockheed Martin CFR
* MFTF
* TMX

Other|

* LDX
* PFRC
* Trisops

Magneto-inertial|

* SPECTOR
* Linus
* FRX-L – FRCHX
* Fusion Engine

Inertial
confinement|

| Laser|

| Americas|

* Argus
* Cyclops
* Janus
* LIFE
* Long path
* NIF
* Nike
* Nova
* OMEGA
* Shiva

|

Asia|

* GEKKO XII

Europe|

* HiPER
* Asterix IV (PALS)
* LMJ
* LULI2000
* ISKRA
* Vulcan

Non-laser|

* PACER
* Z machine

* International Fusion Materials Irradiation Facility
* ITER Neutral Beam Test Facility

*[v]: View this template
*[t]: Discuss this template
*[e]: Edit this template