Polarized Fusion: An Idea More Than Thirty Years Old! What Are We Waiting For?

Ciullo, G.

doi:10.1007/978-3-319-39471-8_1

Cited by 13 publications

(31 citation statements)

References 19 publications

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“…Spin polarization has long been know to affect the radiation emission of fusion reactions and more recently shown to lower the ignition requirements as well. [9,[11][12][13]. Up until now though, it has never been considered for use in fusion rockets.…”

Section: Introductionmentioning

confidence: 99%

The Benefits of Spin Polarization for Inertial and Magneto-Inertial Fusion Propulsion

Bruhaug¹,

Kish²

2021

Preprint

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Section: Introductionmentioning

confidence: 99%

The Benefits of Spin Polarization for Inertial and Magneto-Inertial Fusion Propulsion

Bruhaug¹,

Kish²

2021

Preprint

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“…Все чаще в литературе обсуждается возможность применения поляризованного топлива в термоядерных реакциях синтеза для производства энергии [1]. Так, в случае полностью поляризованных ядер дейтерия и 3 He сечение реакции синтеза увеличивается на 50%.…”

Section: Introductionunclassified

Моделирование Движения Молекул H-=sub=-2-=/Sub=- И D-=sub=-2-=/Sub=- В Секступольных Магнитах

Юрченко¹,

Николенко²,

Рачек³

et al. 2019

Журнал Технической Физики

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The simulation of the movement of hydrogen and deuterium molecules in the magnetic system of the installation designed to obtain nuclear spin-polarized molecules is produced. For the spatial separation of molecules with different projections of the magnetic moments of spin filtering method in a nonuniform magnetic field, superconducting sextupole magnets are used. The calculation was performed when the induction of the magnetic field near the poles of 3.7 T and the nozzle temperature of the 7K. The simulation showed that the ratio of the polarized flux of hydrogen molecules into the detector to the total flux from the source nozzle is 2.3 × 10-6, and the nuclear polarization is about 100%. For deuterium, the calculations showed that this ratio is 7 times less because of the smallness of the magnetic moment with respect to hydrogen molecules. The graphs of molecular trajectories in the magnetic system and their spatial distribution are presented. The mathematical aspects of the developed computer program algorithm are considered.

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“…The total intensity I 0 of the iodine photofragments, and the β 2 coefficient, describing the angular distribution, are expressed in terms of the spatial anisotropy β and a linear combination of the a (1) q (p) parameters [31]:…”

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confidence: 99%

“…Controlling the nuclear spin polarization in fusion reactions offers important advantages, such as larger reaction cross sections, control over the emission direction of products, and in some cases eliminating hazardous neutron emission [1,2]. In the case of the five-nucleon reactions D + T → n + 4 He and D + 3 He → p + 4 He, it is well known that the reaction cross section increases by ∼50% when the fused nuclei have oriented nuclear spins [3,4].…”

mentioning

confidence: 99%

“…q (p) parameters, given by s 1 = − √ 3 G (1) for RCP and s 1 = + √ 3 G (1) for LCP probe light, and G (1) ≈ 0.400 is the time-averaged k=1 hyperfine depolarization coefficient due to the iodine nuclear spin (I = 5/2). Thus, the only way that the intensity I 0 and the β 2 can differ upon reversal of the probe (or photodissociation) laser polarization helicity, is for the iodine atoms to be polarized (i.e.…”

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confidence: 99%

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Highly Nuclear-Spin-Polarized Deuterium Atoms from the UV Photodissociation of Deuterium Iodide

et al. 2017

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We report the production of highly spin-polarized Deuterium atoms via photodissociation of deuterium iodide at 270 nm. The velocity distribution of both the deuterium and iodine photodissociation products is performed via velocity mapping slice-imaging. Additionally, the angular momentum polarization of the iodine products is studied using polarization-sensitive ionization schemes. The results are consistent with excitation of the A 1 Π1 state followed by adiabatic dissociation. The process produces ∼100% electronically polarized deuterium atoms at the time of dissociation, which is then converted to ∼ 60% nuclear D polarization after ∼ 1.6 ns. These production times for hyperpolarized deuterium allow collision-limited densities of ∼ 10 18 cm −3 , which is ∼ 10 6 times higher than conventional (Stern-Gerlach separation) methods. We discuss how such high-density hyperpolarized deuterium atoms can be combined with laser fusion to measure polarized D-D fusion cross sections.PACS numbers: 33.80. Gj, 32.10.Fn Controlling the nuclear spin polarization in fusion reactions offers important advantages, such as larger reaction cross sections, control over the emission direction of products, and in some cases eliminating hazardous neutron emission [1,2]. In the case of the five-nucleon reactions D + T → n + 4 He and D + 3 He → p + 4 He, it is well known that the reaction cross section increases by ∼50% when the fused nuclei have oriented nuclear spins [3,4].For the 4-nucleon D+D reaction, over the important energy range of 10-100 keV, the situation is unclear, since several predictions range from enhancement of the reaction, suppression of the reaction, or almost no effect at all [5][6][7][8][9][10]. The technical challenges of measuring fusion polarization dynamics limits the number of experiments which pursue this direction to two facility-scale experiments [11]. These experiments achieve nuclear spin polarization by magnetically separating the nuclear spin states via the Stern-Gerlach effect in molecular beams, a process however which limits the achievable production rates to ∼ 10 16 atoms s −1 [2], and the projected D-D fusion reaction rate to as low as ∼0.01 neutrons s −1 [12]. Polarized solid deuterium targets can be produced where the densities can reach as high as 2.5 × 10 19 spins/cm 3 , albeit in much lower polarization close to 10% [13]. Another approach for the production of polarized sold fuel involves accumulating the hyperpolarized deuterium in specially coated storage cells [11].Laser photodissociation of hydrogen halides has been shown to produce highly polarized H atoms [14][15][16][17]. The photodissociation process initially polarizes the electron spin up to 100% (for photofragment velocities parallel to the propagation direction of the circularly-polarized dissociation laser) [18]; due to the hyperfine interaction, the polarization oscillates back and forth between the electronic and the nuclear spin on the ∼1-ns timescale. By terminating this polarization exchange appropriately, for example by ioni...

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Polarized Fusion: An Idea More Than Thirty Years Old! What Are We Waiting For?

Cited by 13 publications

References 19 publications

The Benefits of Spin Polarization for Inertial and Magneto-Inertial Fusion Propulsion

The Benefits of Spin Polarization for Inertial and Magneto-Inertial Fusion Propulsion

Моделирование Движения Молекул H-=sub=-2-=/Sub=- И D-=sub=-2-=/Sub=- В Секступольных Магнитах

Highly Nuclear-Spin-Polarized Deuterium Atoms from the UV Photodissociation of Deuterium Iodide

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