Particle-Assisted Trajectory Field Electron Accelerator

Abstract

Disclosed herein is a particle assisted wakefield electron acceleration apparatus, accelerated electrons produced using the apparatus, and methods of use thereof. The apparatus includes an accelerator chamber including a gas cell, the accelerator chamber containing a low density gas and particles therein, the accelerator chamber configured to receive a pulse, the pulse configured to ionize at least a portion of the low density gas, thereby generating a plasma wave (e.g., a wakefield) containing electrons in the accelerator chamber, and to ionize at least a portion of the particles, thereby generating free electrons.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority to U.S. Provisional Application No. 63 / 212,889, filed June 21, 2021, which is incorporated by reference herein in its entirety.

[0002] Statement of government support This invention was made with Government support under Grant No. FA9550-17-1-0264 awarded by the Air Force Office of Scientific Research. The Government has certain rights in this invention. [Background technology]

[0003] Laser wakefield acceleration has the potential to shrink approximately km-scale facilities down to room-sized machines. A major research goal worldwide is to keep the acceleration process active long enough to reach electron energies >10 GeV in a single acceleration stage. The apparatus, methods, and systems discussed herein address these and other needs. Summary of the Invention

[0004] In accordance with the objectives of the disclosed apparatus, methods, and systems as embodied and broadly described herein, the disclosed subject matter relates to particle assisted wakefield electron accelerators, accelerated electrons generated using the apparatus, and methods of use thereof.

[0005] Additional advantages of the disclosed apparatus, systems, and methods will be set forth in part in and in part apparent from the following description. The advantages of the disclosed apparatus, systems, and methods will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosed apparatus, systems, and methods, as claimed.

[0006] The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims. [Brief description of the drawings]

[0007] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several aspects of the disclosure and, together with the description, serve to explain the principles of the disclosure.

[0008] [Figure 1] Wakefield acceleration with the nanoparticle-free Texas Petawatt Laser results in a broad electron spectrum with peak energies of 2-3 GeV. [Diagram 2] Wakefield acceleration with a Texas Petawatt laser using nanoparticle injection can boost peak energies to >10 GeV; however, the exact beam characteristics depend on the detailed spatiotemporal overlap of the nanoparticles with the driver laser pulse. [Diagram 3] Wakefield acceleration with a Texas Petawatt laser using nanoparticle injection can result in a spectrum exhibiting a narrow peak observed at about 6 GeV. The exact beam characteristics depend on the detailed spatiotemporal overlap of the nanoparticles with the driver laser pulse. [Figure 4] Wakefield acceleration with the Texas Petawatt Laser: (top) The absence of nanoparticles results in a broad spectrum with peak energies of 2-3 GeV. Nanoparticle injection boosts the energy to >10 GeV (bottom). [Diagram 5] 1 is a schematic illustration of an exemplary gas cell with a partial cross-sectional view. [Figure 6] 1 is a schematic, illustrative diagram of an exemplary apparatus disclosed herein, according to one embodiment. [Figure 7] 1 is a schematic, illustrative diagram of an exemplary apparatus disclosed herein, according to one embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The apparatus, methods, and systems described herein may be more readily understood by reference to the following detailed description of specific aspects of the disclosed subject matter and the examples included therein.

[0010] Before the present devices, methods, and systems are disclosed and described, it is to be understood that the aspects described below are not limited to specific synthetic methods or to specific reagents, as such may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular aspects only, and is not intended to be limiting.

[0011] Also, throughout this specification, various publications are referenced. The disclosures of these publications in their entireties are hereby incorporated by reference into this application in order to more fully describe the state of the art to which the disclosed subject matter pertains. The references disclosed are also individually and specifically incorporated by reference herein for the material contained in them that is discussed in the sentence in which the reference is relied upon.

[0012] In this specification and the claims that follow, reference will be made to a number of terms that shall be defined to have the following meanings.

[0013] Throughout the description and claims of this specification, the terms "comprise" and other forms of this term, such as "comprising" and "comprises", are not intended to be limiting but are not intended to exclude, for example, other addenda, components, integers or steps.

[0014] As used in the description and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to a "composition" includes mixtures of two or more such compositions, reference to an "agent" includes mixtures of two or more such agents, reference to a "component" includes mixtures of two or more such components, etc.

[0015] "Optional" or "optionally" means that a subsequently described event or circumstance may or may not occur, and the description includes cases where the event or circumstance occurs and cases where it does not occur.

[0016] As used herein, ranges can be expressed from one particular value using "about" and / or to another particular value using "about." "About" means within 5% of the value, for example, within 4%, 3%, 2%, or 1% of the value. When such a range is expressed, another embodiment includes from the one particular value and / or to the other particular value. Similarly, when values ​​are expressed as approximations, by use of the antecedent "about," it will be understood that the particular value constitutes another aspect. It will further be understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint.

[0017] Values ​​may be expressed herein as "average" values. "Average" generally refers to a statistical average value.

[0018] "Substantially" means within 5%, for example, within 4%, 3%, 2%, or 1%.

[0019] "Exemplary" means "an example of" and is not intended to convey an indication of a preferred or ideal embodiment. "Such as" is used for descriptive purposes rather than in a limiting sense.

[0020] It should be understood that throughout this specification, the identifiers "first" and "second" are used solely to aid in distinguishing between various components and steps of the disclosed subject matter. The identifiers "first" and "second" are not intended to imply any particular order, quantity, preference, or importance to the components or steps modified by these terms.

[0021] The term "or combinations thereof" as used herein refers to all permutations and combinations of the listed items preceding the term. For example, "A, B, C, or combinations thereof" is intended to include at least one of the following: A, B, C, AB, AC, BC, or ABC, and, if order is important in a particular situation, BA, CA, CB, CBA, BCA, ACB, BAC, or CAB. Continuing with this example, combinations including repeats of one or more items or terms, such as BB, AAA, AB, BBC, AAABCCCC, CBBAAA, CABABB, etc., are expressly included. One of skill in the art will understand that there is typically no limit to the number of items or terms in any combination, unless otherwise clear from the context.

[0022] Disclosed herein is a particle-assisted wakefield electron accelerator. For example, disclosed herein is a particle-assisted wakefield electron accelerator comprising an accelerator chamber (e.g., a single accelerator chamber) comprising a gas cell. An exemplary gas cell is shown in FIG.

[0023] The accelerator chamber (e.g., gas cell) may be, for example, 0.5 centimeters (cm) or greater (e.g., 0.6 cm or greater, 0.7 cm or greater, 0.8 cm or greater, 0.9 cm or greater, 1 cm or greater, 1.25 cm or greater, 1.5 or greater, 1.75 cm or greater, 2 cm or greater, 2.5 cm or greater, 3 cm or greater, 3.5 cm or greater, 4 cm or greater, 4.5 cm or greater, 5 cm or greater, 6 cm or greater, 7 cm or greater, 8 cm or greater, 9 cm or greater, 10 cm or greater, 11 cm or greater, 12 cm or greater, 13 cm or greater, 14 cm or greater, 15 cm or greater, 16 cm or greater, 17 cm or greater, In some embodiments, the length may be 18cm or more, 19cm or more, 20cm or more, 25cm or more, 30cm or more, 35cm or more, 40cm or more, 45cm or more, 50cm or more, 60cm or more, 70cm or more, 80cm or more, 90cm or more, 100cm or more, 125cm or more, 150cm or more, 175cm or more, 200cm or more, 225cm or more, 250cm or more, 275cm or more, 300cm or more, 325cm or more, 350cm or more, 375cm or more, 400cm or more, 425cm or more, 450cm or more, or 475cm or more. In some embodiments, the accelerator chamber (e.g., gas cell) has a flow rate of 500 cm or less (e.g., 475 cm or less, 450 cm or less, 425 cm or less, 400 cm or less, 375 cm or less, 350 cm or less, 325 cm or less, 300 cm or less, 275 cm or less, 250 cm or less, 225 cm or less, 200 cm or less, 175 cm or less, 150 cm or less, 125 cm or less, 100 cm or less, 90 cm or less, 80 cm or less, 70 cm or less, 60 cm or less, 50 cm or less, 45 cm or less, 40 cm or less, 35 cm or less, 30 cm or less, 2 The accelerator chamber (e.g., gas chamber) may have a length of 5 cm or less, 20 cm or less, 19 cm or less, 18 cm or less, 17 cm or less, 16 cm or less, 15 cm or less, 14 cm or less, 13 cm or less, 12 cm or less, 11 cm or less, 10 cm or less, 9 cm or less, 8 cm or less, 7 cm or less, 6 cm or less, 5 cm or less, 4.5 cm or less, 4 cm or less, 3.5 cm or less, 3 cm or less, 2.5 cm or less, 2 cm or less, 1.75 cm or less, 1.5 cm or less, 1.25 cm or less, 1 cm or less, 0.9 cm or less, 0.8 cm or less, 0.7 cm or less, or 0.6 cm or less. The length of the accelerator chamber (e.g., gas chamber) may range from any of the minimum values ​​listed above to any of the maximum values ​​listed above.For example, the accelerator chamber (e.g., gas cell) can have a length of 0.5 centimeters (cm) to 500 cm (e.g., 0.5 cm to 250 cm, 250 cm to 500 cm, 0.5 cm to 5 cm, 5 cm to 50 cm, 50 cm to 500 cm, 1 cm to 500 cm, 0.5 cm to 450 cm, 1 cm to 450 cm, 0.5 cm to 400 cm, 0.5 cm to 200 cm, 0.5 cm to 100 cm, 1 cm to 50 cm, or 10 cm to 20 cm).

[0024] In some embodiments, the accelerator chamber (e.g., gas cell) is 0.05 cm 3 or more (e.g., 0.06 cm 3 More than 0.07cm 3 More than 0.08cm 3 More than 0.09cm 3 More than 0.1cm 3 More than 0.2cm 3 More than 0.3cm 3 More than 0.4cm 3 More than 0.5cm 3 More than 0.75cm 3 More than 1cm 3 Over 1.25cm 3 Over 1.5cm 3 Over 1.75cm 3 More than 2cm 3 Over 2.25cm 3 Over 2.5cm 3 More than 3cm 3 Over 3.5cm 3 Over 4cm 3 Over 4.5cm 3 More than 5cm 3 More than 6cm 3 More than 7cm 3 More than 8cm 3 That's it, 9cm 3 More than 10cm 3 More than 15cm 3 Over 20cm 3 Over 25cm 3 More than 30cm 3 Above, 35cm 3 More than 40cm 3 More than 45cm 3 More than 50cm3 Above, 60cm 3 Above, 70cm 3 Above, 80cm 3 Above, 90cm 3 Over 100cm 3 Above, 125cm 3 Over 150cm 3 Above, 175cm 3 Over 200cm 3 Above, 225cm 3 Above, 250cm 3 Above, 275cm 3 Above, 300cm 3 Above, 350cm 3 Above, 400cm 3 Above, 450cm 3 Above, 500cm 3 Above, 600cm 3 Above, 700cm 3 Above, 800cm 3 Above, 900cm 3 Above, 1000cm 3 Above, 1250cm 3 Above, 1500cm 3 Above, 1750cm 3 Above, 2000cm 3 Above, 2250cm 3 Above, 2500cm 3 Above, 3000cm 3 Above, 3500cm 3 Above, 4000cm 3 Above, 4500cm 3 Above, 5000cm 3 Above, 6000cm 3 Above, 7000cm 3 Above, 8000cm 3 Above, 9000cm 3 Above, 10,000cm 3 Above, 12,500cm 3 Above, 15,000cm 3 Above, 17,500cm 3 Above, 20,000cm 3 Above, 22,500cm 3 Above, 25,000cm 3 Above, 30,000cm 3More than 35,000cm 3 More than 40,000cm 3 More than 45,000cm 3 More than 50,000cm 3 More than 60,000cm 3 More than 70,000cm 3 More than 80,000cm 3 More than 90,000cm 3 More than 100,000cm 3 More than 125,000cm 3 More than 150,000cm 3 More than 175,000cm 3 More than 200,000cm 3 More than 225,000cm 3 More than 250,000cm 3 More than 300,000cm 3 More than 350,000cm 3 More than 400,000cm 3 or more than 450,000 cm 3 It has a volume of 1000 or more.

[0025] In some embodiments, the accelerator chamber (e.g., gas cell) is configured to have a 500,000 cm 3 Less than (e.g., 450,000 cm 3 Below, 400,000cm 3 Below, 350,000cm 3 Below 300,000cm 3 Below 250,000cm 3 Below, 225,000cm 3 Below 200,000cm 3 Below, 175,000cm 3 Below, 150,000cm 3 Below, 125,000cm 3 Below 100,000cm 3 Below, 90,000cm 3 Below 80,000cm 3 Below 70,000cm 3 Below 60,000cm 3 Below 50,000cm 3 Below, 45,000cm 3Below, 40,000cm 3 Below, 35,000cm 3 Below, 30,000cm 3 Below, 25,000cm 3 Below, 22,500cm 3 Below, 20,000cm 3 Below, 17,500cm 3 Below, 15,000cm 3 Below, 12,500cm 3 Below, 10,000cm 3 Below, 9000cm 3 Below, 8000cm 3 Below, 7000cm 3 Below, 6000cm 3 Below, 5000cm 3 Below, 4500cm 3 Below, 4000cm 3 Below, 3500cm 3 Below, 3000cm 3 Below, 2500cm 3 Below, 2250cm 3 Below, 2000cm 3 Below, 1750cm 3 Below, 1500cm 3 Below, 1250cm 3 Below, 1000cm 3 Below, 900cm 3 Below, 800cm 3 Below, 700cm 3 Below, 600cm 3 Below, 500cm 3 Below, 450cm 3 Below, 400cm 3 Below, 350cm 3 Below, 300cm 3 Below, 275cm 3 Below, 250cm 3 Below, 225cm 3 Below, 200cm 3 Below, 175cm 3 Below, 150cm 3 Below, 125cm 3 Below, 100cm 3 Below, 90cm 3 Below, 80cm 3 Below, 70cm3 Below, 60cm 3 Below, 50cm 3 Below, 45cm 3 Below, 40cm 3 Below, 35cm 3 Below, 30cm 3 Below, 25cm 3 Below, 20cm 3 Below, 15cm 3 Below, 10cm 3 Below, 9cm 3 Below, 8cm 3 Below, 7cm 3 Below, 6cm 3 Below, 5cm 3 Below, 4.5cm 3 Below, 4cm 3 Below, 3.5cm 3 Below, 3cm 3 Below, 2.5cm 3 Below, 2.25cm 3 Less than 2cm 3 Below, 1.75cm 3 Below, 1.5cm 3 Below, 1.25cm 3 Below, 1cm 3 Below, 0.75cm 3 Less than 0.5cm 3 Below, 0.4cm 3 Below, 0.3cm 3 Less than 0.2cm 3 Less than 0.1cm 3 Below, 0.09cm 3 Below, 0.08cm 3 Below, 0.07cm 3 Less than or equal to 0.06cm 3 It has a volume of 100 mm or less.

[0026] The volume of the accelerator chamber (e.g., gas cell) can range from any of the minimum values ​​listed above to any of the maximum values ​​listed above. For example, the accelerator chamber (e.g., gas cell) can have a volume of 0.05 cm 3 ~500,00cm 3 (For example, 0.05 cm 3 ~500cm 3 , 500cm 3 ~500,000cm3 , 0.05cm 3 ~0.5cm 3 , 0.5cm 3 ~5cm 3 , 5cm 3 ~50cm 3 , 50cm 3 ~500cm 3 , 500cm 3 ~5000cm 3 , 5000cm 3 ~50,000cm 3 , 50,000cm 3 ~500,000cm 3 , 0.05cm 3 ~450,000cm 3 , 0.5cm 3 ~50,000cm 3 , or 0.5 cm 3 ~450,000cm 3 )

[0027] The accelerator chamber includes a low density gas and particles therein. The low density gas can include any suitable gas. In some embodiments, the low density gas includes hydrogen, helium, nitrogen, or the like, or a combination thereof. In some embodiments, the low density gas includes helium.

[0028] The accelerator chamber has a proximal end and a distal end, the proximal end being an end configured to receive a pulse. In some embodiments, the particles are located at or near the proximal end of the accelerator chamber. In some embodiments, the particles can be located at or near the distal end of the accelerator chamber. In some embodiments, the particles include a plurality of particles distributed throughout the accelerator chamber. The plurality of particles can be distributed, for example, uniformly, non-uniformly, sequentially, or randomly throughout the accelerator chamber.

[0029] As used herein, "a particle" and "the particle" are meant to include any number of particles in any arrangement. In some embodiments, a particle is a single particle. In some embodiments, a particle is a plurality of particles (e.g., 2 or more, 3 or more, 4 or more, 5 or more, 10 or more, 15 or more, 20 or more, 25 or more, 30 or more, 40 or more, 50 or more, 75 or more, 100 or more, 150 or more, 200 or more, 250 or more, 300 or more, 400 or more, 500 or more, 750 or more, 1000 or more, 1500 or more, 2000 or more, 2500 or more, 3000 or more, 4000 or more, 5000 or more, 7500 or more, 1×10 4 That's it, 2.5 x 10 4 That's it, 5 x 10 4 That's it, 7.5 x 10 4 That's it, 1×10 5 That's it, 2.5 x 10 5 That's it, 5 x 10 5 That's it, 7.5 x 10 5 That's it, 1×10 6 That's it, 5 x 10 6 That's it, 1×10 7 That's it, 5 x 10 7 That's it, 1×10 8 That's it, 5 x 10 8 That's it, 1×10 9 That's it, 5 x 10 9 That's it, 1×10 10 That's it, 1×10 11 That's it, 1×10 12 That's it, 1×10 13 That's it, 1×10 14 That's it, 1×10 15 That's it, 1×10 16 That's it, 1×10 17 That's it, 1×10 18 That's it, 1×10 19 or more, or 1×10 20 That's all.

[0030] The particles can include any suitable material. For example, the particles can include metals, semi-metals, non-metals, derivatives thereof, or combinations thereof. The particles can include, for example, semiconductors, ceramics, transparent conductive oxides, polymers, carbon materials, metals (e.g., alloys), nitrides, oxides, silicides, germanides, carbides, derivatives thereof, or combinations thereof.

[0031] In some embodiments, the particles can include Be, B, C, Mg, Al, Si, P, S, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, As, Se, Sr, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sn, Sb, Te, Ba, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Tl, Pb, Bi, Po, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, or combinations thereof.

[0032] In some embodiments, the particles include metal particles. In some embodiments, the metal particles include a metal selected from the group consisting of Be, Mg, Al, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Sr, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sn, Ba, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Tl, Pb, Bi, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and combinations thereof. In some embodiments, the metal particles include a metal selected from the group consisting of Al, Cr, Mn, Fe, Co, Ni, Cu, Mo, Pd, Ag, Pt, Au, and combinations thereof.

[0033] Particles can have an average particle size. "Average particle size" and "mean particle size" are used interchangeably herein and generally refer to the statistical average particle size of particles in a particle population. For example, the average particle size of a plurality of particles having a substantially spherical shape can include the average diameter of the plurality of particles. For particles having a substantially spherical shape, the diameter of the particle can refer to, for example, the hydrodynamic diameter. As used herein, the hydrodynamic diameter of a particle can refer to the maximum linear distance between two points on the surface of the particle. The average particle size can be measured using methods known in the art, such as by scanning electron microscopy, transmission electron microscopy, atomic force microscopy, X-ray microscopy, and / or dynamic light scattering evaluation.

[0034] In some examples, the particles are 1 nanometer (nm) or greater (e.g., 2 nm or greater, 3 nm or greater, 4 nm or greater, 5 nm or greater, 6 nm or greater, 7 nm or greater, 8 nm or greater, 9 nm or greater, 10 nm or greater, 15 nm or greater, 20 nm or greater, 25 nm or greater, 30 nm or greater, 35 nm or greater, 40 nm or greater, 45 nm or greater, 50 nm or greater, 60 nm or greater, 70 nm or greater, 80 nm or greater, 90 nm or greater, 100 nm or greater, 125 nm or greater, 150 nm or greater, 175 nm or greater, 200 nm or greater, 225 nm or greater, 250 nm or greater, 300 nm or greater, 350 nm or greater, 400 nm or greater, 450 nm or greater, 500 nm or greater, m or more, 600 nm or more, 700 nm or more, 800 nm or more, 900 nm or more, 1 micrometer (micron, μm) or more, 1.25 μm or more, 1.5 μm or more, 1.75 μm or more, 2 μm or more, 2.5 μm or more, 3 μm or more, 3.5 μm or more, 4 μm or more, 4.5 μm or more, 5 μm or more, 6 μm or more, 7 μm or more, 8 μm or more, 9 μm or more, 10 μm or more, 15 μm or more, 20 μm or more, 25 μm or more, 30 μm or more, 35 μm or more, 40 μm or more, 45 μm or more, 50 μm or more, 60 μm or more, 70 μm or more, 80 μm or more, or 90 μm or more.In some examples, the particles are 100 micrometers (microns, μm) or less (e.g., 90 μm or less, 80 μm or less, 70 μm or less, 60 μm or less, 50 μm or less, 45 μm or less, 40 μm or less, 35 μm or less, 30 μm or less, 25 μm or less, 20 μm or less, 15 μm or less, 10 μm or less, 9 μm or less, 8 μm or less, 7 μm or less, 6 μm or less, 5 μm or less, 4.5 μm or less, 4 μm or less, 3.5 μm or less, 3 μm or less, 2.5 μm or less, 2 μm or less, 1.75 μm or less, 1.5 μm or less, 1.25 μm or less, 1 μm or less, 900 nm or less, 800 nm or less, 700 nm or less, The particles may have an average particle size of 600 nm or less, 500 nm or less, 450 nm or less, 400 nm or less, 350 nm or less, 300 nm or less, 250 nm or less, 225 nm or less, 200 nm or less, 175 nm or less, 150 nm or less, 125 nm or less, 100 nm or less, 90 nm or less, 80 nm or less, 70 nm or less, 60 nm or less, 50 nm or less, 45 nm or less, 40 nm or less, 35 nm or less, 30 nm or less, 25 nm or less, 20 nm or less, 15 nm or less, 10 nm or less, 9 nm or less, 8 nm or less, 7 nm or less, 6 nm or less, 5 nm or less, 4 nm or less, 3 nm or less, or 2 nm or less. The average particle size of the particles may range from any of the minimum values ​​recited above to any of the maximum values ​​recited above. For example, the particles can have an average particle size of 1 nanometer (nm) to 100 micrometers (microns, μm) (e.g., 1 nm to 100 nm, 100 nm to 100 μm, 1 nm to 10 nm, 10 nm to 100 nm, 100 nm to 1000 nm, 1000 nm to 10 μm, 10 μm to 100 μm, 10 nm to 100 μm, 1 nm to 90 μm, 10 nm to 90 μm, or 1 nm to 1000 nm).

[0035] In some embodiments, the particles can be substantially monodisperse. As used herein, "monodisperse" and "uniform size distribution" generally refer to a population of particles in which all particles are the same or approximately the same size. As used herein, a monodisperse distribution refers to a particle distribution in which 80% of the distribution (e.g., 85% of the distribution, 90% of the distribution, or 95% of the distribution) is within 25% of the median particle size (e.g., within 20% of the median particle size, within 15% of the median particle size, within 10% of the median particle size, or within 5% of the median particle size).

[0036] The particles can include particles of any shape (e.g., spheres, rods, quadrilaterals, ellipses, triangles, polygons, etc.). In some embodiments, the particles can have a regular shape, an irregular shape, an isotropic shape, or an anisotropic shape. In some embodiments, the particles have a substantially spherical shape.

[0037] The accelerator chamber containing the low-density gas and particles is configured to receive a pulse, the pulse being configured to ionize at least a portion of the low-density gas, thereby generating a plasma wave (e.g., a wake field) containing electrons in the accelerator chamber. The pulse is further configured to ionize at least a portion of the particles, thereby generating free electrons. At least a portion of the electrons from the plasma and at least a portion of the free electrons are injected into the wake field, the portion of the electrons from the plasma and the portion of the free electrons being the injected electrons. The injected electrons are, for example, accelerated by the wake field, thereby generating an electron beam. If the acceleration length is long enough, the initial acceleration in the wake field can be followed by further acceleration in a plasma wake field (PWFA) driven by the electron flux accelerated in the initial wake field. The electrons accelerated in this second process can reach even higher energies. An exemplary apparatus is shown in FIG. 6.

[0038] The injected electrons can be accelerated to energies of 10 gigaelectronvolts (GeV) or greater (e.g., 15 GeV or greater, 20 GeV or greater, 25 GeV or greater, 30 GeV or greater, 35 GeV or greater, 40 GeV or greater, 45 GeV or greater, 50 GeV or greater, 60 GeV or greater, 70 GeV or greater, 80 GeV or greater, 90 GeV or greater, or 100 GeV or greater).

[0039] In some embodiments, the injected electrons can be accelerated to energies that are 400% or more (e.g., 425% or more, 450% or more, 475% or more, 500% or more, 525% or more, 550% or more, 575% or more, 600% or more, 650% or more, 700% or more, 750% or more, 8000% or more, 900% or more, or 1000% or more) greater than the energy that would be generated in the absence of the particles.

[0040] In some embodiments, the apparatus further comprises a particle injector configured to inject particles into the accelerator chamber. Any suitable particle injector may be used. In some embodiments, the particle injector comprises a gas jet. In some embodiments, the particle injector comprises an aerodynamic lens configured to inject a stream of particles into the accelerator chamber.

[0041] In certain embodiments, the apparatus further comprises a particle source configured to provide the particles.

[0042] In certain embodiments, the particles may include metal particles, and the apparatus may further include an ablation laser configured to ablate a metal target, thereby generating the metal particles, as shown in FIG.

[0043] In some embodiments, the pulse comprises a laser pulse. In some embodiments, the apparatus can further comprise a laser source configured to generate the laser pulse.

[0044] In some embodiments, the pulse has a defocusing length that is greater than the length of the accelerator chamber.

[0045] Also disclosed herein are methods of generating an electron beam using any of the devices disclosed herein. Also disclosed herein are methods of using the electron beam generated by the methods disclosed herein.

[0046] Although several embodiments of the present invention have been described, it will be understood that various modifications can be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims.

[0047] The following examples are intended to further illustrate certain aspects of the systems and methods described herein, and are not intended to limit the scope of the claims. EXAMPLES

[0048] The following examples are described below to illustrate methods and results according to the disclosed subject matter. These examples are not intended to be inclusive of all aspects of the subject matter disclosed herein, but rather to illustrate representative methods and results. These examples are not intended to exclude equivalents and variations of the present invention that are apparent to those skilled in the art.

[0049] Efforts have been made to ensure accuracy with respect to numbers (e.g., amounts, temperature, etc.), but some errors and deviations should be accounted for. Unless otherwise indicated, parts are parts by weight, temperature is in °C or is ambient temperature, and pressure is at or near atmospheric. There are numerous variations and combinations of measurement conditions, e.g., component concentrations, temperatures, pressures, and other measurement ranges and conditions that can be used to optimize the described processes.

[0050] Example 1 - Laser wakefield acceleration above 10 GeV with nanoparticle injection Collision of an ultra-intense laser field with a highly relativistic electron beam is the only currently known way to create an EM field beyond the Schwinger limit, which gives the best opportunity to observe quantum processes in strongly relativistic fields. Since current high energy electron accelerators do not have co-located ultra-intense lasers, the only viable way is to accelerate the electron beam via wakefield acceleration using the laser itself. Furthermore, laser wakefield acceleration has the potential to shrink approximately km-scale facilities to room-sized machines that are affordable for individual users such as hospitals, corporations, etc., and even make them small enough to be mobile. Thus, GeV electron beams become available for many applications at relatively low cost and with great availability. GeV electron beams power modern light sources such as SLAC's Linac Coherent Light Source and Argonne National Laboratory's Advanced Photon Source. They have revolutionized research in materials science, medical and pharmaceutical research, security and nonproliferation, and many other fields. Unfortunately, these facilities are highly oversubscribed and the available beam time is limited, especially for private commercial users and classified national security applications. However, building larger accelerator facilities is prohibitively expensive. Laser-driven electron accelerators can solve this problem, as they can create and use acceleration gradients 10,000 times larger (>GV / cm vs. about 10MV / m). Acceleration to the same energy can therefore be achieved over a 1000-10,000 times shorter distance. Even when considering the laser and associated hardware, the result is a room-sized machine, rather than a kilometer-scale.

[0051] Although proof-of-principle experiments have long since demonstrated their true potential, laser accelerators are still laboratory experiments rather than functioning machines, and the beams are still in many ways inferior to conventional accelerators. A detailed physical understanding of the acceleration process and how to control it in detail are the subject of current cutting-edge research and development. A major research goal worldwide is to keep the acceleration process active long enough to reach electron energies >10 GeV in a single acceleration stage. This is a requirement that has been identified for both laser-driven XFELS and laser-based colliders. Other significant research efforts are focused on controlling the beam parameters such as charge, divergence, and energy spread.

[0052] Results: A method that allows increasing the beam energy and controlling other beam parameters is nanoparticle-assisted wakefield electron acceleration (NA-LWFA).

[0053] Using a modified NA-LWFA method, acceleration of electron bunches to peak energies of >10 GeV was demonstrated using a Texas Petawatt laser at a power level of about 0.8 PW. Electrons were accelerated in a 10 cm long gas cell filled with helium without the use of additional guiding structures such as capillaries or preheated plasma channels. Electron injection into the wake was triggered by aluminum nanoparticles distributed throughout the helium gas. A 4-5 times enhancement in electron energy was observed at optimal conditions from about 2-3 GeV to peak energies of about >10 GeV, as shown in Figures 1-3. The observed beam charge is in the nanocoulomb range and the beam divergence is about 1-2 mrad. Individual electron peaks observed over several shots exhibit an energy spread of only a few percent. The results of the first proof-of-principle experiment with the Petawatt laser exhibit a large stochasticity since the Texas Petawatt laser is a single shot laser (about 4 shots / day) with significant laser pulse fluctuations in the wavefront. However, in many years of wakefield experiments without nanoparticles, energies >2.5 GeV have not been observed over hundreds of shots. In a single experiment with nanoparticles, all shots that produced electron beams at all peak energies were greater than 3 GeV, often between 5 and 7 GeV, and at least twice greater than 10 GeV. The nanoparticles are randomly distributed throughout the entire acceleration volume, adding further stochasticity to the process, leading in some cases to a nanoparticle being in the perfect spot for the maximum energy, while in other shots, multiple nanoparticles contribute to the acceleration, producing multiple electron bunches.

[0054] Moreover, this method can also work in smaller sub-PW laser systems, making it attractive for a wide range of applications and systems. Proof-of-principle NA-LWFA experiments using a 100 TW laser beamline at CoReLS showed a ~50% increase in beam energy, a ~3x reduction in divergence, and a ~10x reduction in energy spread.

[0055] The previous record in LWFA was achieved in an experiment conducted by a team from the BELLA Center at Lawrence Berkeley National Laboratory. They used a very complex setup including a 20 cm discharge capillary, a laser heater, and a 0.88 PW primary laser to generate a 7.8 GeV electron beam, which was the world record at the time. This kind of design produces very high electron energies, but it also has many drawbacks. For example, the pointing stability of the main laser and the laser heater needs to be very good, since the inner diameter of the capillary is several hundred microns. On the other hand, the target of the system described herein is 3 cm wide with a 3 mm pinhole aperture. Another problem is related to the discharge capillary, which requires an elaborate pulsed power setup. Also, the capillary is quickly damaged due to the discharge, which poses a significant challenge for high repetition rate operation. The target of the system described herein does not use any discharge or pulsed power and thus does not suffer from the same problems. Additionally, the capillary walls make any optical probing of the interaction region very difficult, whereas the gas cell of the system described herein provides much easier access for diagnostics. Finally, the LBNL setup requires a 20 cm target to achieve 7.8 GeV, whereas the setup described herein reaches >10 GeV in only 10 cm.

[0056] Further work can be done to understand and control the complex nanoparticle-laser interactions and injection physics. Initial results suggest that the observed energies were limited by the target size, not the physics. What governs the injection physics, as well as its dependence on nanoparticle properties such as size, material, and position, can be further investigated. Multi-particle injection was observed in some shots, but not all. It can be further investigated to what extent the demonstrated gains can be transferred to smaller, higher repetition rate systems, and whether further optimization could increase the gain even more.

[0057] In additional experiments, the particle energy achievable with a single TPW driven stage will be maximized. The dependence of acceleration on laser and target parameters will be investigated to optimize the electron beam charge and emittance, and a detailed understanding of nanoparticle physics can be obtained by processing advanced diagnostics. These goals can be achieved by collecting more experimental data, improving diagnostics, optimizing targets, and performing simulations of the experiments to understand the detailed mechanisms. Large-scale, high-resolution simulations can be performed using the PIC code PSC with its unique adaptive mesh refinement capabilities. PSC was used to successfully model the first AWAKE experiment (Moschuering, N. et al. “First fully kinetic three-dimensional simulation of the AWAKE baseline scenario.” Plasma Physics and Controlled Fusion 61.10(2019):104004).

[0058] The results here show that the observed electron energies are limited by the length of the target, currently 10 cm. Therefore, in additional experiments, longer targets (15-20 cm) will be used, with which it is believed that electron energies of about 15 GeV are achievable. The ability to obtain the highest peak energies and at the same time a very narrow energy spread will also be investigated.

[0059] Such experiments can provide a detailed understanding of laser-based electron acceleration >10 GeV and potential gains up to 15-20 GeV from a single stage. Control of other beam parameters such as charge, emittance, and energy spread can also be achieved. The results can bring plasma-based electron acceleration closer to applications. Furthermore, the developed techniques, targets, diagnostics, and algorithms can be used in other facilities to upscale or downscale results for specific applications.

[0060] Example 2 - Electron beams above 10 GeV via nanoparticle-assisted laser wakefield acceleration Laser wakefield acceleration has the potential to scale down from approximately km-scale facilities to room-sized machines. A major research goal worldwide is to keep the acceleration process active long enough to reach electron energies >10 GeV in a single acceleration stage. This is a requirement that has been identified for both laser-driven XFELS and laser-based colliders.

[0061] Using nanoparticle-assisted laser wakefield acceleration, electron acceleration to energies >10 GeV has been demonstrated in a Texas Petawatt. This is an increase of about 5 times compared to previous results with the same laser system (Wang, X. et al., Nat. Commun. 4, (2013)). Electrons were accelerated in a 10 cm long He-filled gas cell with no additional guiding structures. Electron injection and acceleration are assisted by aluminum nanoparticles distributed throughout the helium gas. Peak energies of >10 GeV were observed, as shown in Figure 4. The observed charges were in the nanocoulomb range and the beam divergence was about 0.5 mrad.

[0062] The work on nano-LWFAs can be extended towards even higher electron energies, aiming for 15-20 GeV from a single stage driven by a Texas Petawatt Laser. These results can be transferred to higher repetition rate (sub- and multi-) Petawatt (PW) lasers to improve the control of beam parameters. The energies achievable with LWFAs are affected by the dephasing between the electron and the wakefield, the laser pump depletion, and the defocusing. In experiments with the Texas Petawatt Laser, pump depletion is not an issue and the dephasing length can be estimated as follows: L deph = λ 2 p / λ 2 a0 Here, λ pis the plasma wavelength, and a0 is the normalized vector potential. In the experiments described here, a0 = 3 and λ P = 43.1 μm, and the phase shift length L deph = 21.7 cm, which is much longer than the 10 cm long gas cell, suggesting that the achieved peak energy of 10.4 GeV could be further increased by increasing the gas cell length. Using the validated fluid dynamics simulations, improved versions of the nano-LWFA target could be developed that would allow for longer acceleration lengths and better control of nanoparticle injection. This target could be processed in experiments at the Texas Petawatt Laser in conjunction with the advanced probe interferometer demonstrated by H.-E. Tsai (Dissertation. UT Austin (2015)). The target could also be adapted for shorter pulse, higher repetition rate petawatt systems. Extended simulations could be performed to understand the underlying physical mechanisms of nanoparticle-assisted LWFA. For example, the PIC code PSC with its unique adaptive mesh refinement capability could enable large-scale, high-resolution simulations. PSCs were used to successfully model the first AWAKE experiment (Moschuering, N., et al. Plasma Physics and Controlled Fusion 61.10(2019):104004).

[0063] In recent experiments with the Texas Petawatt Laser, a 100 pC charge was accelerated to 10 GeV in a single LWFA stage. Additional experiments will focus on improving stability, reproducibility, and tunability. In addition to fulfilling these goals, the versatility of the proposed technique makes it interesting for a wide range of applications.

[0064] The goal of this project is to demonstrate a stable 10-15 GeV single stage laser wakefield accelerator. Experiments will be performed with the Texas Petawatt Laser, which will include designing and processing modified nano-LWFA targets to increase acceleration length and provide better control over nanoparticles. (Alternatively, lasers other than the Texas Petawatt Laser could be used.) Higher repetition rates and laser stability combined with better nanoparticle control could allow for better control of electron beam parameters. These efforts may be supported by advanced PIC simulations.

[0065] This project can yield a stable single stage laser accelerator generating 10-15 GeV electron beams with >100 pC charge. The target is very robust, does not require capillaries or heater beams, and is much less susceptible to damage. Greater control of the nanoparticles can allow control of other beam parameters such as charge and emittance, which may be important for eventual applications such as wakefield-driven FEL, or the unit stage of a laser-based electron collider. This result has the potential to change the paradigm in the field of plasma-based electron acceleration and beyond.

[0066] Example 3 – Nanoparticle-assisted electron wakefield accelerator Described herein are systems and methods that use nanoparticles to trigger the injection of electrons into a plasma wakefield. This allows for greater control of the injection process, and therefore the subsequent acceleration process. Nanoparticle injection allows control over the location and timing of injection, the number of electrons injected, the number of electron bunches accelerated, and the beam properties of the accelerated electrons: particle energy, beam divergence, and pulse length, i.e., spatial and temporal emittance, as well as the number of electrons per bunch and number of bunches.

[0067] Initial experiments with the Texas Petawatt Laser showed a more than five-fold increase in particle energy over older methods that did not use nanoparticles, and achieved the first demonstration of >10 GeV electrons from a laser accelerator, achieving a community milestone that has been sought for more than a decade. 10 GeV single-stage electrons are a requirement for laser-driven e+e- colliders as well as laser-driven XFELS.

[0068] The systems and methods described herein also work with smaller laser systems and allow for higher pulse energies for a given laser system, as well as improving other beam parameters, and are therefore important in any future applications of laser electron accelerators and light sources.

[0069] The systems and methods described herein improve the energy of laser-accelerated electrons and allow full control of several beam parameters (charge, emittance, energy, pulse duration) of the laser-accelerated electrons. As a result, the systems and methods described herein provide better control and better parameters for the same laser system. The systems and methods described herein allow energies >10 GeV from petawatt lasers.

[0070] The systems and methods described herein allow for the maximum acceleration length possible for a given set of laser and target parameters, and allow for controlled injection of electrons into the accelerating wakefield, and control of beam parameters. The systems and methods described herein work for a wide range of wakefield accelerators: laser-driven, beam-driven, over a wide range of densities, gas jet, gas cell.

[0071] The systems and methods described herein are simpler, more compact, and more versatile than other methods: they achieve high energies in only half the length, have a much simpler setup than other methods, and do not use multiple large laser beams or inherently damaging discharges.

[0072] The systems and methods described herein may have one or more of the following advantages: a five-fold increase in energy, a two-fold improvement in emittance, reduced pulse duration, increased charge, and bunch number control.

[0073] The systems and methods described herein may be of interest to accelerator companies, accelerator laboratories, light sources, healthcare, pharmaceuticals, biological research, materials science research, homeland security, anyone who uses advanced x-ray sources, synchrotrons, FELs, electron accelerators, etc.

[0074] Other advantages which are obvious and inherent to the present invention will be apparent to those skilled in the art. It will be understood that certain features and subcombinations are useful and may be employed without reference to other features and subcombinations. This is contemplated by and within the scope of the appended claims. Because many possible embodiments can be made of the present invention without departing from the scope of the invention, it should be understood that all matter described or shown in the accompanying drawings is to be understood as illustrative and not in a limiting sense.

[0075] The apparatus, systems, and methods of the appended claims are not limited in scope by the specific apparatus, systems, and methods described herein, which are intended as illustrations of some aspects of the claims, and any methods that are functionally equivalent are intended to fall within the scope of the claims. Various modifications of the apparatus, systems, and methods in addition to those shown and described herein are intended to fall within the scope of the appended claims. Furthermore, although only certain representative apparatus elements, system elements, and method steps disclosed herein have been specifically described, other combinations of apparatus elements, system elements, and method steps are also intended to fall within the scope of the appended claims, even if not specifically set forth. Thus, although combinations of steps, elements, components, or elements may be explicitly referred to herein or hereinafter, other combinations of steps, elements, components, or elements are included, even if not explicitly set forth.

Claims

1. A particle accelerator comprising an accelerator chamber having a length of up to 500 cm, wherein the particle accelerator is configured to accelerate electrons to an energy of at least 10 GeV within the accelerator chamber, Particle accelerator.

2. The particle accelerator according to claim 1, wherein the accelerator chamber comprises a gas cell.

3. The particle accelerator according to claim 2, wherein the gas cell contains a low-density gas.

4. The particle accelerator according to claim 2, wherein the gas cell contains particles.

5. The particle accelerator according to claim 4, wherein the particles include metal particles.

6. The particle accelerator according to claim 4, wherein the gas cell is configured to contain particles.

7. The particle accelerator according to claim 1, wherein the accelerator chamber is configured to receive a pulse.

8. The particle accelerator according to claim 7, wherein the pulse is a laser pulse.

9. The particle accelerator according to claim 7, wherein the pulse is directed towards the accelerator chamber.

10. The particle accelerator according to claim 9, wherein the pulse is configured to generate electrons within the accelerator chamber by at least partially ionizing a low-density gas and particles.

11. The particle accelerator according to claim 10, wherein the low-density gas is configured to form a plasma wave based on ionization.

12. The particle accelerator according to claim 11, wherein the plasma wave is a wakefield.

13. The particle accelerator according to claim 11, wherein the plasma wave contains the electrons.

14. The particle accelerator according to claim 13, wherein the plasma wave is configured to accelerate the electrons.

15. The particle accelerator according to claim 1, further comprising a particle source configured to provide particles.

16. The particle accelerator according to claim 15, wherein the particle source includes an ablation laser configured to ablate a target to generate particles.

17. A method of accelerating electrons, comprising: (a) providing a particle accelerator having a length of up to 500 cm; and (b) accelerating particles to an energy of at least 10 GeV within the chamber of the particle accelerator. Method.

18. A particle-assisted wakefield accelerator comprising an accelerator chamber configured to contain a gas and particles, and an ionization laser. Ionization laser Particle-assisted wakefield accelerator comprising The ionization laser is configured to ionize a part of the gas and the particles to generate free electrons, the ionization laser field, the free electrons, and the particles are configured to generate a wakefield, the wakefield is configured to accelerate incident electrons within a plasma wave to generate an energy wave, a particle-assisted wakefield accelerator.

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