“Flying focus” techniques produce laser pulses with dynamic focal points that can travel distances much greater than a Rayleigh length. The implementation of these techniques in laser-based applications requires the design of optical configurations that can both extend the focal range and structure the radial group delay. This work describes a method for designing optical configurations that...
Designs for linear colliders based on laser wakefield acceleration (LWFA) must address dephasing, which occurs when trapped particles outpace the accelerating phase of the wakefield. To address dephasing, current designs employ many stages, each operating at a low plasma density, which limits the acceleration gradient and elongates both the individual stages and total collider length. Here, we...
Laser Wakefield Acceleration (LWFA) offers a promising alternative to conventional accelerators, offering superior acceleration gradients. However, the effect of radiation reaction inside the wakefield can be detrimental to their operation. The transverse focusing field in the wakefield can drive betatron oscillations and cause radiation emission, with radiation back-reaction effects on the...
Scaling laws for laser-plasma interactions can be expressed in various ways. One approach is to apply a transformation that leaves the governing equations invariant and ask how the overall system is modified, and treat technological limitations as a set of constraints. This talk will examine such transformations with particular attention to reductions in laser wavelength, with a view toward...
When an ultra-intense laser pulse propagates through a dense plasma, the front of the laser can be locally “etched” by the nonlinear laser-plasma interaction, forming an optical shock. The laser front edge becomes extremely sharp, reaching relativistic amplitude over a sub-wavelength scale. This gives rise to the Carrier-Envelope-Phase (CEP) effect in laser wakefield accelerators (LWFA),...
Next generation laser drivers for laser plasma acceleration and secondary radiation sources will require 3 to 4 orders of magnitude increase in pulse repetition rates, to produce TW-PW class peak power ultrashort pulses at multi-kilowatt average powers [1]. Coherently combined ultrashort pulse fiber laser systems are recognized as a pathway to such high power technology [1]. However, although...
Compact laser plasma accelerators running at repetition rates >1 kHz promise a wide range of applications in science research, medicine, and security. Commercially available laser systems operating at kHz repetition rates offer mJ pulses with pulse duration as low as tens fs. To fulfill the resonant condition for the laser wakefield acceleration, temporal compression of these pulses is...
The laser pulse properties required for a future laser-driven collider are routinely demonstrated with Hz class Ti:Sa lasers; however, a four orders of magnitude increase in repetition rate will be necessary to meet collider luminosity specifications [1]. We model thermal effects in Ti:Sa amplifiers, including thermal effects at high repetition rate, using an operator splitting approach that...
Precise control of the temporal shape of ultrashort pulses of terawatt scale peak power is often desirable in experiments. In previous work, we used single, few-cycle 5 fs pulses for 1 kHz rep. rate laser wakefield acceleration (LWFA) to 15 MeV in near-critical density hydrogen plasma [1]. Double pulses are also of interest for LWFA, as prior simulation studies suggest that resonant driving of...
The advanced accelerator community increasingly recognizes the importance of extending high peak- and average-power laser facilities to longer wavelengths. This recognition is driven by the lambda-squared scaling of the ponderomotive force, inverse-lambda-squared scaling of critical plasma density, and linear-lambda scaling of the number of photons per joule of energy. A significant potential...
We describe recent results from our programme to develop high-repetition-rate, GeV-scale plasma-modulated plasma accelerators (P-MoPAs).
This programme seeks to take advantage of advanced thin-disk lasers (TDLs) that can deliver joule-scale pulses, at kHz repetition rates, but with a pulse duration that is too long ($\sim 1\,\mathrm{ps}$) to drive a wakefield directly at the densities of...
Recently developed techniques for optical generation of low density (≤10^17 cm^(-3)), meter-scale hydrodynamic plasma waveguides in extended supersonic gas jets [1-3] have already enabled a new class of fully-optical multi-GeV laser wakefield accelerators [4,5]. Optimization of the laser wakefield acceleration (LWFA) process in these types of waveguides and plans for future, single-stage 100...
Hydrodynamic plasma waveguides initiated by optical field ionization (OFI) have recently become a key component of multi-GeV laser wakefield accelerators [1–4], We present comprehensive experimental and simulation-based characterization, applicable both to current multi-GeV experiments and future 100 GeV-scale laser plasma accelerators. Crucial to the simulations is the correct modeling of...
Laser wakefield accelerators (LWFA) have long promised to revolutionize particle acceleration by shrinking facility size and cost by orders of magnitude. Despite twenty years of experiments however, we do not understand the performance envelope of LWFAs. Experiments and simulations demonstrate a wide range of possible operating points, ranging from high-charge beams to high-energy beams. ...
We report on electron-beam collimation using a passive plasma lens[1], integrated directly into a laser wakefield-accelerator stage operating in the high-charge regime. The lens is created by the reshaping of the gas-density profile of a supersonic jet at the beam’s exit side. It reduces the beam’s divergence by a factor of 2 to below 1 mrad (rms), while preserving the total charge of 170 pC...
Given a very short and intense plane-wave laser pulse travelling in the positive $z$ direction, we propose a multi-step preliminary analytical procedure to tailor the initial density profile $\widetilde{n_0}(z)$ of a cold diluted collisionless plasma to the pulse, so as to control the formation of the plasma wave (PW), its wave-breaking (WB) at density inhomogeneities, the self-injection of...
We report self-injecting LWFA driven by CPA-CO2 laser pulses of wavelength ~10 micrometers at Brookhaven's Accelerator Test Facility [1]. Long-wave IR pulses open opportunities to drive large wakes in low-density plasma more efficiently than near-IR pulses, potentially enabling higher-quality accelerated bunches. In experiments, 0.5-TW, 4-ps laser pulses generated no electrons, but drove...
A tunable laser positron source as originally described in [1] is being prototyped using the collocated LWIR CO2 laser and electron beam at BNL-ATF. Unlike LPA, this work deals with interaction of three distinct entities, a laser, a pair-plasma, and laser-driven electron density structures.
This work relies on the advantages of larger size of electron density structures excited by the CO2...
The plasma accelerator community has made significant progress in advancing particle beams, bringing us closer to realizing the dream of replacing the radio frequency (RF) cavities' MV/m fields with the plasma-sustained GV/m fields for collider applications. The beam requirements for realizing this vision emphasize a collider-quality beam featuring hundreds of pC of charge, energy spread less...
Laser wakefield acceleration (LWFA) using laser-ablated metallic plasma targets has been developed for high-vacuum and high-repetition rate operations. The metallic plasma density (called the pre-plasma) generated by laser-ablation is increased via the optical ionization process due to intense fs laser pulse (called the main laser). The optical guiding of main laser in the plasma is influenced...