Method and device for laser nuclear synthesis

Abstract

It is proposed a method and device for the realization and reaching the required parameters for a nuclear reaction of light nucleus in liquid. The time for the plasma sustainability is achieved by excitation of long train of high peak intensity ps pulses. The preliminary estimations show a power intensity of 1019 - 1020 W / cm2 ( corresponding for the wavelength of 1064nm is round 5.1011 V / m electric field ). It is observed, that the emission of the D ions at 656nm continues after the end of the excitation and ions recombination life time, which leads to the conclusion that a high energy exothermal reaction is triggered.

Description

[0001] D E S C R I P Tl O N

[0002] METHOD AND DEVICE FOR LASER NUCLEAR SYNTHESIS

[0003] Field of science and invention : Physics of nuclear fusion and Lasers.

[0004] Early state of the problem, BACKGROUND. Shortly

[0005] From the rime of discovering the nuclear decay and radioactivity, a question is put : joining light nucleus in bigger element - synthesis . The theoretical ground is based mostly on to overcome the Coulomb electric forces between charged particles and to reach a sustainable reaction / 1 /

[0006] Where

[0007] Where n is plasma density , τ - is the plasma life time, k - Boltzmann constant, T - temperature, a - reaction cross section , v - ions velocity, Q - system energy balance , c <> Mazwell distribution average velocity at T. For the stationary case is essential that the energy of the protons to be higher that the Coulomb barrier , which for the reaction D - D is round 15 keV

[0008] The most possible reactions, requiring less initiating energy are

[0009] Obviously the ways to achieve this are two:

[0010] Increasing the time of the “hot” plasma, i.e. the energy of the ions

[0011] - Increasing the concentration of high energy ions There are many projects , at least 18 , for creating conditions and which are based on different effects

[0012] - Keep the stability of the plasma in magnetic fields, electrostatic acceleration , colliding beams , inertial laser initiating and other versions. It is achieved, in many laboratories, a synthesis, but for a short time and low concentration. So , the process do not release enough energy to continue. There are more efforts, scientific, engineering and finance needed, because additional problems arise, mostly connected with the instability of the plasma.

[0013] In the systems, which are based on laser inertial excitation , several dependencies on the accumulation with several fs pulses and resonance with the plasma waves 12 , 31 , substantial increase of the effect of double pulse excitation in liquids / 4 / , self-focusing of ps pulses / 5 / , the plasma life time and other investigations, cited in the literature.

[0014] DETAILED DESCRIPTION OF THE INVENTION

[0015] The proposed method and device, which distinguish them from the existing projects and inventions , is to design a system with laser, which satisfy the basic requirements :

[0016] - Conditions for keeping the plasma in high concentration of D2, T3target ( in this case heavy water D2O )

[0017] Excitation with long train high peak power laser pulses ( 20 - 30 ps , with 1015- 1017W / cm2power intensity ) after the initial focusing

[0018] - Conditions for the concentrated plasma in small dimension, by using the effects of self- focusing and molecular forces

[0019] - Controlled and regulated pulses frequencies, close to some resonance of the plasma frequencies, so the time between the sequent pulses to be less than the ions life time - the recombination to atom state

[0020] - The excitation time to be as long as possible, in order to accumulate the energy of the sequent pulses

[0021] - Possibility , after saturation of the ions saturation, to generate a higher power laser pulse, in order to initiate an exothermal reaction and reaching the level of quasi continuous self- sustained reaction.

[0022] The method is based on the pointed requirements, in the way that the different effects to combine through the time of excitation. There are three thresholds , dependent on the excitation power intensity

[0023] First threshold. Breakdown and ionization of the D2O molecule. Accumulation of the energy of the sequent pulses, which is monitored by the intensity of the a line of the D ion. The broadening of the line is an estimation for their energy - temperature or velocity Second threshold. Because of the high peak optical power, the total index of refraction multiplied by the high level of the electric field , is changed and the laser beam is self- focused to a smaller diameter / 5 / , which leads to the increase of the plasma length towards the incident beam. The estimation of the diameter is close to the wavelength , 2 - 5 μm . This, the optical power intensity reaches 1015- 1017W / cm2.

[0024] Third threshold. After reaching a saturation of the a line of the D ion ( round 656nm ) , which a figure of merit for their concentration , the laser delivers a higher peak power ps pulse. At 0.015 - 0.020 J pulse energy, the power intensity reaches 1015- 1017W / cm2

[0025] The concentration of the D ions are comparable with number of molecules in water, and when at least 1% are with energies ( Maxwell distribution ) to ever come the Coulomb barrier , the threshold for self sustained reaction is reached.

[0026] To realize the method requirement, a laser system is designed, and consisting of :

[0027] - Oscillator on the bases of mode locked laser . The frequency of the ps pulses train is determined by the double trip in the resonator. A version of such oscillator is presented in

[0028] / 5 , 7 , 8 / . Thus the time between pulses may be regulated between 3 - 15 ns. The oscillator has 2 output beams with orthogonal polarizations, The second beam is optically delayed before entering the second chain of amplifiers. Through this set up the time between the ps pulses may be regulated from 0 to coinciding with the next pulse and to realize a resonant excitation / Fig.1 / . For example , at a delay of appr. 0.7 ns the basic resonant of the D atom , round 1 ,42 GHz is reached. When saturation od the excitation is reached, the oscillator delivers a much higher energy pulse with the rest energy contained in the active media. The system may run with pulse repetition rate, determined by the power of the amplifiers, and in case of lamp pumped active media, it may teach 100 Hz and more.

[0029] - 2 or 4 amplifier chains which are polarization coupled in 1 or 2 single beams. 2 beams is a version for colliding beams set up.

[0030] - The amplified pulses trains are focused in cuvette filled with 100% D2O at room temperature and pressure

[0031] - The cuvette is placed inside a thick , metal housing with high absorption of the emitted neutrons and other emissions.

[0032] - There are holes where is the monitoring devices, as Gated Camera and Gated spectrometer with 100ns - 1ms resolution

[0033] - The thermal yield is measured by the heat in the metal housing

[0034]

[0035] The preliminary results show, that breakdown and ionization of D atoms, a plasma cloud is form with dimensions, close to the focus dimension . Further is the SECOND threshold for the self-focusing, and the plasma cloud increases only in the directions of the excitation beam. When the cuvette is not long enough , the plasma reaches the input / output quartz windows and destroy them. We estimate the optical power intensity to reach 1019- 1020W / cm2

[0036] Fig.1 Tdelayl is determined by the resonator lenght 3 - 15 ns Tdelay2 from the optical delay line 0- 15 ns

[0037] Example of the realization.

[0038] Some of the data are pointed in the above text. Summarized the results are :

[0039] Maximum energy of the ps pulse train, including the released high power ps pulse for single side excitation is round 5 J . The first threshold is achieved at 100 — 150 mJ The second threshold round 200 mJ at a delay from the start of 1 - 2 μs. The length of the plasma cloud reaches 1 —3 cm. The diameter of the plasma cord is not measured, because of the diffraction of the illuminating beam and the resolution of the Gated Camera.

[0040] The emission of the 656 nm line continues for at least 0.1 ms after the end of the pulses train excitation. Refferrences :

[0041] 1. Some Criteria for a Power Producing Thermonuclear Reactor, J D Lawson, B „ IOPscience“

[0042] 2. “Resonant excitation of plasma waves in a plasma channef’n , PHYSICAL REVIEW RESEARCH 6, L022001 (2024)

[0043] 3. Excitation and Control of Plasma Wakefields by Multiple Laser Pulses , PRL 119, 044802 (2017)

[0044] 4. “Double-pulse UBS in water with up to 600 bar hydrostatic pressure and up to 150 mJ energy of each pulse" , Spectrochimica Acta Part B: Atomic Spectroscopy, Volume 213 March 2024, 106877

[0045] 5. „ Self-focusing and frequency broadening of laser pulse in water" , Phys. Plasmas 21 , 112110 (2014)

[0046] 6. P.Yankov, G. Petrov : “High Energy Negative Feedback Controlled Passively ML Nd:YAG Laser” , Appl.Phys. B , 54 , 231-233 , (1992)

[0047] 7. P.Yankov, LAngelov : “High Energy Long Pulse Trains ps Nd:YAG Laser “ , OQE 24 , 1173-1179 , (1992)

[0048] 8. P.Yankov : “Phase Loop AM ML of Nd:Glass Laser with NFC” , Meas.Sci.Techn. , 4 , 392-394 , (1993)

Claims

CLAIMS1. A method for reaching the requirements for a self - sustained nuclear reaction of a synthesis of light nucleus , characterized in keeping the hot plasma in liquid for long time in shorter than the ions recombination intervals time with nonlinear effects increasing the electrical field intensity, without destroying the plasma cord2. A device for achieving the requirements for self sustained nuclear reaction of synthesis of light nucleus through long time lived plasma in high concentration liquid , characterized in mode locked laser oscillator delivering long train of pulses and a chain of amplifiers chains including possibility for colliding beams realization.

Images