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High power laser transmission is being intensively researched as a potential solution to transfer power to remote systems, being the power converter (PC) one of the main limiting factor to improve the system efficiency ( $\eta $ ). Current PCs are mostly horizontal structures in which the $\eta $ heavily decreases at large input power. In this work, we propose a novel GaAs-based vertical-tunnel-junction (VTJ) PC suitable for ultra-high (UH) input power density (P in ). This structure does not suffer from $\eta $ degradation at high P in because it is designed to have low current density, high output voltage and reduced series resistance (~ 2 orders of magnitude lower than the state-of-the-art PCs). We have demonstrated increasing $\eta $ with P in , reaching values higher than 76% at 3000 $\text{W}\cdot $ cm −2 . This vertical-based architecture enables a new set of potential applications for wireless PC to power remote systems with $\eta $ exceeding today’ s state-of-the-art PC designs.

In this work we determine the 14 C content in a graphite bar used in the core of the research nuclear reactor TRIGA MARK III, at the “Instituto Nacional de Investigaciones Nucleares” (ININ) in Mexico. The 14 C / 12 C ratio was measured, using Accelerator Mass Spectrometry (AMS) at the Laboratorio Nacional de Espectrometria de Masas con Aceleradores (LEMA) at the ”Instituto de Fisica de la Universidad Nacional Autonoma de Mexico” (IFUNAM). Our results show a 14 C ratio over three orders of magnitude higher than that found in modern organic matter. A γ -ray spectroscopy study of the graphite bar with a High Purity Germanium detector (HPGe) shows the presence of the same radioactive isotopes reported in previous studies of similar bars.

Dynamically-tunable impedance matching is a key feature in numerous radio-frequency (RF) applications at high frequencies (10 s of MHz) and power levels (100s–1000 s of Watts and above). This work develops techniques that enable the design of high power tunable matching networks (TMN) that can be tuned orders of magnitude faster than with conventional tunable impedance matching techniques, while realizing the high power levels required for many industrial applications. This is achieved by leveraging an emerging technique – known as phase-switched impedance modulation (PSIM), which involves switching passive elements at the rf operating frequency – that has previously been demonstrated at rf frequencies at up to a few hundred Watts. In this paper, we develop design approaches that enable it to be practically used at up to many kilowatts of power at frequencies in the 10 s of MHz. A detailed analysis of the factors affecting the losses as well as the tradeoffs of a basic PSIM-based element is provided. Furthermore, it is shown how incorporating additional stages to the PSIM-based element, including impedance scaling and / or the addition of series or shunt passive elements, influences the losses and enables the efficient processing of high power levels given the limitations of available switches. A PSIM-based TMN that matches load impedances to 50 $\,\Omega$ and delivers up to 1.5 kW of power at frequencies centered around 13.56 MHz is implemented and tested over a load impedance range suitable for various industrial plasma processes.

We have experimentally improved the temporal contrast of the petawatt J-KAREN-P laser facility. We have investigated how the generation of pre-pulses by post-pulses changes due to the temporal overlap between the stretched pulse and the post-pulse in a chirped-pulse amplification system. We have shown that the time at which the pre-pulse is generated by the post-pulse and its shape are related to the time difference between the stretched main pulse and the post-pulse. With this investigation, we have found and identified the origins of the pre-pulses and have demonstrated the removal of most pre-pulses by eliminating the post-pulse with wedged optics. We have also demonstrated the impact of stretcher optics on the picosecond pedestal. We have realized orders of magnitude enhancement of the pedestal by improving the optical quality of a key component in the stretcher.

This paper presents a new approach based on the use of a Current Steering (CS) technique for the design of fully integrated Gm–C Low Pass Filters (LPF) with sub-Hz to kHz tunable cut-off frequencies and an enhanced power-area-dynamic range trade-off. The proposed approach has been experimentally validated by two different first-order single-ended LPFs designed in a 0.18 µm CMOS technology powered by a 1.0 V single supply: a folded-OTA based LPF and a mirrored-OTA based LPF. The first one exhibits a constant power consumption of 180 nW at 100 nA bias current with an active area of 0.00135 mm2 and a tunable cutoff frequency that spans over 4 orders of magnitude (~100 mHz–152 Hz @ CL = 50 pF) preserving dynamic figures greater than 78 dB. The second one exhibits a power consumption of 1.75 µW at 500 nA with an active area of 0.0137 mm2 and a tunable cutoff frequency that spans over 5 orders of magnitude (~80 mHz–~1.2 kHz @ CL = 50 pF) preserving a dynamic range greater than 73 dB. Compared with previously reported filters, this proposal is a competitive solution while satisfying the low-voltage low-power on-chip constraints, becoming a preferable choice for general-purpose reconfigurable front-end sensor interfaces.

As the highest power proton linear accelerator in continuous wave mode, China initiative Accelerator Driven sub-critical System linear accelerator will deliver 2.5 MW proton beam to the target inside the reactor. Vacuum transition from $5\ifmmode\times\else\texttimes\fi{}{10}^{4}\text{ }\text{ }\text{ }\mathrm{Pa}$ to several ${10}^{\ensuremath{-}6}\text{ }\mathrm{Pa}$ is required at the accelerator to target section. A vacuum differential system located at the transfer line is designed to meet the requirement of the windowless target and upstream collimators are considered for power loss control in this paper. A vacuum test based on vacuum transition verifies that about 10 orders of magnitude vacuum transition could be achieved as required, and gas scattering simulation shows that the power loss and beam size increase are at an acceptable level before the last magnet.

SLAC is pursuing high efficiency, low cost RF source designs that are suitable for mass production, in order to enable the next generation of linear accelerators. These efforts have driven the development of compact linac systems with integrated modulators, klystrons, and accelerator structures, based on a modular, low voltage klystron topology. There is substantial demand for compact linacs for X-ray radiography with security applications, and for new radiation therapy machines that reduce treatment times by orders of magnitude and may yield beneficial biological effects. In this presentation, details and challenges for these new compact accelerator systems and the corresponding RF sources are discussed.

We demonstrate the impact of the optics roughness in Öffner stretchers used in chirped pulse amplification laser chains and how it is possible to improve the temporal contrast ratio in the temporal range of 10–100 ps by adequately choosing the optical quality of the key components. Experimental demonstration has been realized in the front-end source of the multi-petawatt (PW) laser facility Apollon, resulting in an enhancement of the contrast ratio by two to three orders of magnitude.

The Paul Scherrer Institute (PSI) provides the world's highest intensity muon beam of Ó(108)μ+/s at 28MeV/c. The HiMB project aims to improve this rate by two orders of magnitude. Meanwhile, the muCool collaboration is developing a device which converts a standard surface μ+ beam of cm-size and MeV-energy into a beam of 1mm-size and 1eV energy spread by achieving a compression of 6-dimensional phase space by 10 orders of magnitude with an efficiency of 10−3., PoS: Proceedings of Science, 369, ISSN:1824-8039, Proceedings of the 21st international workshop on neutrinos from accelerators

A dual-frequency Doppler Lidar (DFDL) with high precision utilizing a monolithic integrated two-section DFB laser as the dual-frequency light source is proposed and experimentally demonstrated. The DFDL can be realized with smaller size using the monolithic integrated two-section DFB laser which is fabricated by the reconstruction-equivalent-chirp (REC) technique with high precision and low fabrication cost. The range of the measured speed is from 13.62 μm /s to 1.56 m/s, which covers 6 orders of magnitude. The largest relative error of the DFDL system is 3.16%. The DFDL system has an excellent resolution of 1.95 μm/s, which is suitable to detect micro speed changes.

We report the generation of unprecedented 10 PetaWatt laser pulses obtained from each of the two beamlines of the High Power Laser System (HPLS) of ELI-NP (Extreme Light Infrastructure – Nuclear Physics) research infrastructure. The laser system is a hybrid system made of a double CPA based on amplification within Titanium Sapphire crystals combined with an OPCPA with a parametric amplification stage boosting the energy to 10 mJ at the entrance of the second CPA. A XPW filter is also inserted between the two CPA and in combination with the OPCPA improves the temporal contrast of the pulses by typically 7 orders of magnitude. The spectral effects occurring during amplification such as gain narrowing and wavelength shifting are compensated through the use of spectral filters. Final amplification stages are involving large aperture Ti:Sapphire crystals (up to 200 mm) which are pumped by high energy frequencydoubled Nd:Glass lasers delivering each 100 J of green light. Laser beams have been amplified respectively up to 332 J and to 342 J of pulse energy at 1 shot per minute without any occurrence of ASE and transverse lasing thanks to index matching fluid surrounding the crystal over is entire length and pump deposition management over the time before each beam pass within the Ti:Sapphire crystal. We have demonstrated full aperture compression by metric gratings of these amplified pulses down to 22.6 fs and therefore made the full demonstration for the first time ever of 10 PW capability from a laser system.

Recess gate AlGaN/GaN millimeter-wave power high-electron-mobility transistors (HEMTs) with N2O plasma treatment on access region have been fabricated. A thin oxide layer formed on the gate region leads to the gate leakage current at least three orders of magnitude lower than that of conventional recess gate HEMT, which results a ultralow off-state current of $9.4 \times 10^{-7}$ mA/mm accompanied by an on/off ratio of over 108, and a suppressed current collapse of about 4% due to a simultaneous plasma treatment on the gate–source and the gate–drain regions. The forward and the reverse gate-bias stress measurements show that the increment in gate current is within an order of magnitude, indicating an excellent stability of the thin oxide layer. The large signal measurement shows that the HEMT with SiN passivation can yield an output power density of 6 W/mm associated with a peak power-added efficiency (PAE) of 46.8% and a gain of 6.8 dB ( ${V}_{\rm \textsf {ds}}= 25$ V), and an output power density of 4.3 W/mm with a PAE of 59.4% and a gain of 6.6 dB ( ${V}_{\rm \textsf {ds}}= 15$ V), respectively, at 30 GHz. The small signal measurement shows that the HEMT without SiN passivation can yield $f_{T}$ and ${f}_{\rm \textsf {max}}$ of 85 and 274 GHz, respectively.

Cr:ZnSe laser amplifier resulted more than 40 uJ , 72fs pulses, at X0 ~ 2375nm. The CEP stability of the parametrically generated seed stands firm through 6 orders of magnitude of amplification.

The detection of a gravitational wave signal in September 2015 by LIGO interferometers, announced jointly by LIGO collaboration and Virgo collaboration in February 2016, opened a new era in Astrophysics and brought to the whole community a new way to look at - or “listen” to - the Universe. In this regard, the next big step was the joint observation with at least three detectors at the same time. This configuration provides a twofold benefit: it increases the signal-to-noise ratio of the events by means of triple coincidence and allows a narrower pinpointing of GW sources, and, in turn, the search for Electromagnetic counterparts to GW signals. Advanced Virgo (AdV) is the second generation of the gravitational-wave detector run by the Virgo collaboration. After a shut-down lasted 5 years for the upgrade, AdV has being commissioned to get back online and join the two advance LIGO (aLIGO) interferometers to realize the aforementioned scenario. We will describe the challenges and the status of the commissioning of AdV, and its current performances and perspectives. A few lines wil be also devoted to describe the latest achievements, occurred after the TAUP 2017 conference.

A series of experiments are reported which serve as milestones in the development of the MPFD technology. Each test involved reactor pulsing, a controlled power excursion that results from rapid removal of control rods. During a reactor pulse, the power level increases by several orders of magnitude in a fraction of a second resulting from prompt-critical neutron generation in the core. Preliminary reactor pulse testing was conducted at the Kansas State University TRIGA Mk. II nuclear reactor (KSU). The MPFD was used to track reactor pulses of $2.77 and $2.50 worth of reactivity insertion with measured Full Widths at Half Maximum (FWHM) of 13.2 and 16.1 ms compared to theoretical FWHM of 12.2 and 14.4 ms using the Fuchs-Nordheim Model. At the University of Wisconsin Madison Nuclear Reactor (UWNR), a set of 7 detectors, each with 4 independent chambers was deployed as part of the NEUP–NEAMS collaboration between UWNR and KSU. Nine of the time-synchronized chambers were able to track six reactor pulses to provide a spatial map of neutron flux. Finally, a two-chamber MPFD was deployed inside the Idaho National Laboratory Transient Reactor Test Facility (TREAT) reactor core and successfully monitored the power excursion of a 15 GW reactor pulse with an estimated neutron flux of ~1018 n/cm2/s. These preliminary tests highlight the multi-faceted capability of the MPFD as an instrument in different research and power reactors.

A commercial off-the-shelf silicon photomultiplier (SiPM) has been incorporated into a photon counting VLC receiver. In order to minimize the number of background counts in 500 lux of ambient light this receiver is used in conjunction with a 405 nm transmitter, specifically a laser diode. Data was transmitted over the resulting link using on-off keying and a bit-error-rate (BER) of less than 10−3 was achieved for data-rates greater than 420 Mbps. Furthermore, these data rates were achieved with received optical powers of 10 nW (−50 dBm). This means that they are orders of magnitude more sensitive than receivers that use PIN photodiodes.

Review of scientific instruments 90(5), 053301 - (2019). doi:10.1063/1.5086822, We report on the calibration of GafChromic HD-v2 radiochromic film in the extremely high dose regime up to 100 kGy together with very high dose rates up to 7 × 1011 Gy/s. The absolute calibration was done with nanosecond ion bunches at the Neutralized Drift Compression Experiment II particle accelerator at Lawrence Berkeley National Laboratory (LBNL) and covers a broad dose dynamic range over three orders of magnitude. We then applied the resulting calibration curve to calibrate a laser driven ion experiment performed on the BELLA petawatt laser facility at LBNL. Here, we reconstructed the spatial and energy resolved distributions of the laser-accelerated proton beams. The resulting proton distribution is in fair agreement with the spectrum that was measured with a Thomson spectrometer in combination with a microchannel plate detector., Published by American Institute of Physics, [S.l.]

An Infrared Free Electron Laser (IR-FEL) has been designed and developed at RRCAT for potential use in the IR/THz spectroscopy of materials in low temperature and high magnetic field environment. The first commissioning experiments on the IR-FEL setup were performed in 2016, but the out-coupled power achieved in these experiments was two to three orders of magnitude lower than the saturated out-coupled power predicted by the FEL design simulations, mainly due to certain limitations in its injector system. The setup has recently undergone a major upgrade with the installation and commissioning of a new injector system, and lasing at a wavelength of 28 μ m has recently been observed in the setup. This is the first saturation of lasing of an FEL in India, with a measured Continuous Wave (CW) out-coupled IR power of 5 - 7.3 mW. This paper discusses the present status of the IR-FEL project at RRCAT, and the results from recent commissioning experiments leading to lasing in the setup.

Wi-Fi has traditionally been considered a power-consuming communication system and has not been widely adopted in the sensor network and Internet of Things (IoT) space. We introduce Passive Wi-Fi that demonstrates that one can generate 802.11b transmissions using backscatter communication, while consuming 3-4 orders of magnitude lower power than existing Wi-Fi chipsets. Passive Wi-Fi transmissions can be decoded on any Wi-Fi device including routers, mobile phones and tablets. Our experimental evaluation shows that passive Wi-Fi transmissions can be decoded on off-the-shelf smartphones and Wi-Fi chipsets over distances of up to 100 feet. We also design a passive Wi-Fi IC that shows that 1 and 11 Mbps transmissions consume 14.5 and 59.2 ?W respectively. This translates to 10000x lower power than existing Wi-Fi chipsets and 1000x lower power than Bluetooth LE and ZigBee.

Philosophical transactions of the Royal Society of London / A Mathematical, physical and engineering sciences Series A 377(2151), 20180392 - (2019). doi:10.1098/rsta.2018.0392, The FLASHForward experimental facility is a high-performance test-bed for precision plasma wakefield research, aiming to accelerate high-quality electron beams to GeV-levels in a few centimetres of ionized gas. The plasma is created by ionizing gas in a gas cell either by a high-voltage discharge or a high-intensity laser pulse. The electrons to be accelerated will either be injected internally from the plasma background or externally from the FLASH superconducting RF front end. In both cases, the wakefield will be driven by electron beams provided by the FLASH gun and linac modules operating with a 10 Hz macro-pulse structure, generating 1.25 GeV, 1 nC electron bunches at up to 3 MHz micro-pulse repetition rates. At full capacity, this FLASH bunch-train structure corresponds to 30 kW of average power, orders of magnitude higher than drivers available to other state-of-the-art LWFA and PWFA experiments. This high-power functionality means FLASHForward is the only plasma wakefield facility in the world with the immediate capability to develop, explore and benchmark high-average-power plasma wakefield research essential for next-generation facilities. The operational parameters and technical highlights of the experiment are discussed, as well as the scientific goals and high-average-power outlook., Published by Soc., London

We present a sub-µW Neural Spike Processor integrated with a Power Management Unit (PMU) for on-implant processing in motor intention decoding, demonstrating: (i) among the highest level of integration including spike detection, feature extraction, sorting, the first half of decoding, which reduces wireless data rate by more than 4 orders of magnitude; (ii) on-chip PMU integration enabling the system directly powered by harvesters; (iii) the lowest power dissipation of 0.78µW for 96 channels, 21x lower than the prior art at a comparable/better accuracy.

With gain-normalized dark currents reduced below 10 e-/s/pixel, HgCdTe Avalanche Photo-Diode arrays operated in linear mode are now widely accepted as the sensors of choice for adaptive optics wavefront sensing of natural guide stars in the wavelength range 1 to 2.5 um. At lower temperatures the intrinsic dark currents in Leonardo’s SAPHIRA 320 x 256 @ 24um pitch arrays have recently been shown to be four orders of magnitude lower, approaching 0.001 e-/s/pixel. This has opened the way to megapixel class APD arrays offering major advantages for a wide range of low background astronomical observations. We report the status of development of a 1k x 1k @ 15um pixel Read-Out Integrated Circuit (ROIC) for a three-side close-buttable, 16 output, MOVPE HgCdTe array with reference pixels and reference outputs. The design has been optimized for minimum ROIC glow following a detailed investigation of glow sources in the SAPHIRA ME1001 ROIC. This involved precisely overlaying J-band glow images on layout drawings from EDA software to identify all the sources of glow. As of the time of submission of this abstract, the Architecture definition is in its third iteration and the program is on track to produce ROICs around mid-2018. In parallel, Mark 20 SAPHIRAs optimized for very low background operation with the goal of delaying the onset of tunnel-tunnel current to bias voltages producing useful avalanche gain are being characterized along with modified SAPHIRAs with 15um pixels.

Utilizing the modulation transfer spectroscopy (MTS) technique, we realize a compact pumping laser at 459 nm based on cesium (Cs) 62S 1/2 F=4 to 72p 1/2 F'=3 transition with a stability of 1. 8 $\times 10^{-14}/\sqrt{\tau}$ and decreasing to $8\times 10^{-15}$ at 60 s. The 459 nm pumping laser stabilized by MTS technique, achieves the stability by about 2 orders of magnitude better than that of the saturation absorption spectroscopy (SAS), which will contribute to the linewidth reduction of 1470 nm ultimate laser in Cs four-level active optical clock. The 1470 nm stimulated radiation can reach a power of $100 \ \mu\mathbf{W}$ with the stabilized 459 nm pumping laser power being 6 mW. Such a stable laser not only can be used as the pumping laser in active optical clock system, but also a novel optical frequency standard for length and other applications.

Recently, high brightness and broadband supercontinuum (SC) sources reaching far into the infrared (IR) have emerged with the potential to rival traditional broadband sources of IR radiation. Here, the brightness of these IR SC sources is compared with that of synchrotron IR beamlines and SiC thermal emitters (Globars). It is found that SC sources can deliver a brightness that is 5–6 orders of magnitude higher than Globars and 1–2 orders of magnitude higher than typical IR beamlines, matching the beamlines at least out to 10.6 µm (940 cm−1). This means that these sources can now cover nearly all of the 800–5000 cm−1 spectrum (2–12.5 µm) which is frequently used in IR spectroscopy and microscopy. To demonstrate applicability, such an IR SC source was used for transmission spectroscopy of highly scattering filtration membranes from 3500 to 1300 cm−1, and transmission microscopy of colon tissue at 1538 cm−1.

Soft X-ray lasers (SXRLs) produce the highest energy pulses of coherent ultrashort wavelength radiation. Their large number of photons per pulse allow us to perform single-shot imaging of nanoscale objects, to develop material composition sensitive nanoprobes, and to conduct interferometric diagnostics of bright dense plasmas. However, until recently, with the exception of capillary discharge lasers at 46.9 nm, their average power was limited by the low repetition rate of the high energy optical pump lasers required to drive them and by the relatively low pumping efficiency. To overcome this limitation, we have developed a diode-pumped, picosecond Yb:YAG CPA laser driver that allowed us to demonstrate the first table-top SXRL capable of 100 Hz repetition rate gain saturated operation. These new pump lasers combined with efficient plasma heating techniques enable the operation of SXRLs at four orders of magnitude higher repetition rate than the first plasma-based collisional SXRLs (Fig. 2.1). Laser operation at 100 Hz repetition rate generated an average power of 0.2 mW at 18.9 nm (Ni-like Mo) and 0.1 mW at λ = 13.9 nm (Ni-like Ag). We have recently improved upon this diode-pumped laser technology, demonstrating a record 0.5 kHz repetition rate, 1 J, picosecond laser with good beam quality and high stability. We will discuss the results of the first demonstration of a compact table-top soft X-ray laser at repetition rates up to 400 Hz using this new pump laser.

The increasing demand for high laser powers is placing huge demands on current laser technology. This is now reaching a limit, and to realise the existing new areas of research promised at high intensities, new cost-effective and technically feasible ways of scaling up the laser power will be required. Plasma-based laser amplifiers may represent the required breakthrough to reach powers of tens of petawatt to exawatt, because of the fundamental advantage that amplification and compression can be realised simultaneously in a plasma medium, which is also robust and resistant to damage, unlike conventional amplifying media. Raman amplification is a promising method, where a long pump pulse transfers energy to a lower frequency, short duration counter-propagating seed pulse through resonant excitation of a plasma wave that creates a transient plasma echelon that backscatters the pump into the probe. Here we present the results of an experimental campaign conducted at the Central Laser Facility. Pump pulses with energies up to 100 J have been used to amplify sub-nanojoule seed pulses to near-joule level. An unprecedented gain of eight orders of magnitude, with a gain coefficient of 180 cm−1 has been measured, which exceeds high-power solid-state amplifying media by orders of magnitude. High gain leads to strong competing amplification from noise, which reaches similar levels to the amplified seed. The observation of 640 Jsr−1 directly backscattered from noise, implies potential overall efficiencies greater than 10%.

The use of infrared lasers to power optical-scale lithographically fabricated particle accelerators is a developing area of research that has garnered increasing interest in recent years. The physics and technology of this approach is reviewed, which is referred to as dielectric laser acceleration (DLA). In the DLA scheme operating at typical laser pulse lengths of 0.1 to 1 ps, the laser damage fluences for robust dielectric materials correspond to peak surface electric fields in the $\mathrm{GV}/\mathrm{m}$ regime. The corresponding accelerating field enhancement represents a potential reduction in active length of the accelerator between 1 and 2 orders of magnitude. Power sources for DLA-based accelerators (lasers) are less costly than microwave sources (klystrons) for equivalent average power levels due to wider availability and private sector investment. Because of the high laser-to-particle coupling efficiency, required pulse energies are consistent with tabletop microJoule class lasers. Combined with the very high (MHz) repetition rates these lasers can provide, the DLA approach appears promising for a variety of applications, including future high-energy physics colliders, compact light sources, and portable medical scanners and radiative therapy machines.

[1] The Suomi National Polar-Orbiting Partnership (NPP) launched on 28 October 2011 hosts the Visible Infrared Imaging Radiometer Suite (VIIRS) sensor. The VIIRS sensor includes a day-night band (DNB) that covers almost 7 orders of magnitude in its dynamic range from full sunlit scenes to lunar-illuminated clouds. The DNB is panchromatic and covers the wavelengths from 500 nm to 900 nm. Since launch, extensive effort has gone into its characterization. We have shown that the DNB is performing extremely well, meeting most of its specifications with some minor exceedances. The DNB characteristics evaluated include the following: sampling and resolution across the swath, geolocation uncertainty, radiometric sensitivity, radiometric uncertainty, and stray light. The only significant deviation from specification involves the stray light specification. On-orbit, the characterization shows that the DNB suffers stray light level on the order of 100% Lmin or 3 × 10−9 W∙cm−2∙sr−1. After algorithmic correction, the residual radiometric error was reduced to approximately 4.5 × 10−10 W∙cm−2∙sr−1.

The present paper aims to shortly review a relatively new approach to magnetron sputtering, namely “enhanced ionization sputtering” (EIS) or as it is more commonly known “High Power Pulsed Magnetron Sputtering“ (HIPIMS). The EIS concept describes a range of plasmas that have the common features of exhibiting a higher (than what is commonly known) plasma density and a higher ionization fraction of sputtered and gas atoms in the discharge. The somewhat unique properties are the result of pulsing a sputtering source (target) power at a low frequency ranging from a few tens to a few hundreds of Hz and a low duty time of less than 10 %. Consequently, plasma electron densities 2 to 4 orders of magnitude higher than densities in conventional sputtering plasmas can be achieved, while the corresponding ionization fractions of the target material reach up to 90 % for Ti, for example. As will be shown in the present paper, EIS is described as an approach to sputtering that provides new means and a realm of possibilities to develop coating solutions not possible otherwise. This implies that there is not a single description of a HIPIMS plasma, rather a concept for ionization (EIS) that should be used according to the needs of the application in hand. Nevertheless, for the purpose of simplicity, HIPIMS should describe in the present paper both the concept and the technique. Ionenunterstutztes Sputtern in HIPIMS In dem vorliegende Artikel wird uber neue Erfahrungen bei Sputterprozessen mit hoher Ionendichte („Enhanced Ionization Sputtering”, EIS) – besser bekannt unter dem Namen “High Power Pulsed Magnetron Sputtering” (HIPIMS) – berichtet. Das EIS-Konzept beschreibt einen Bereich des Plasmas in dem eine hohere Plasmadichte vorherrscht als in konventionellen Plasmen und in dem sowohl der Ionisationsgrad der Gasteilchen als auch der gesputterten Atome groser ist. Diese besonderen Eigenschaften des Plasmas resultieren aus der Pulsung der Leistung an der Sputterquelle (Target) im Frequenzbereich von einigen zehn bis hundert Hz und einer kurzen Arbeitszyklusdauer (duty time) von ca. 10 %. Dies kann bei entsprechender Ausstattung des Pulsers (z.B. iPulse, INI coatings Ltd.) zu enormen hohen (∼5 A/cm2) Stromdichten fuhren. Die daraus resultierenden Elektronendichten konnen zwei bis vier Grosenordnungen hoher sein als die mit konventionellen Sputterplasmen erzielten, wahrend der korrespondierende Ionisationsgrad des Targetmaterials beispielsweise bis zu 90 % fur Ti reicht. Die EIS-Plasmen eroffnen damit vielzahlige Moglichkeiten fur Beschichtungen, die mit herkommlichen Plasmen nicht erreicht werden konnen. So kann dann auch nicht von dem HIPIMS-Plasma an sich gesprochen werden, sondern eher von einem Konzept fur Ionisation (EIS), das unter Berucksichtigung der jeweiligen Anwendungsanforderung angepasst werden muss. Zur Vereinfachung wird der Begriff HIPIMS in diesem Artikel sowohl fur das Konzept als auch die Technik verwendet.

Acta crystallographica / A 69(5), 490 - 497 (2013). doi:10.1107/S0108767313019612, A ptychographic coherent X-ray diffractive imaging (PCDI) experiment has been carried out using 7.9 keV X-rays and Kirkpatrick-Baez focusing mirrors. By introducing a semi-transparent central stop in front of the detector the dynamic range on the detector is increased by about four orders of magnitude. The feasibility of this experimental scheme is demonstrated for PCDI applications with a resolution below 10 nm. The results are compared with reference data and an increase of resolution by a factor of two is obtained, while the deviation of the reconstructed phase map from the reference is below 1%., Published by IUCR, [S.l.]

X-ray optics have revolutionized x-ray astronomy; the degree of background suppression that these afford has led to a tremendous increase in sensitivity. The current Chandra observatory has the same collecting area (∼10 3 cm 2 ) as that of the non-imaging UHURU observatory, the first x-ray observatory which was launched in 1970, but has five orders of magnitude more sensitivity due to its focusing optics. In addition, its 0.5″ angular resolution has revealed a wealth of structure in many cosmic x-ray sources. The Chandra observatory achieved its resolution by using relatively thick pieces of Zerodur glass, which were meticulously figured and polished to form the four-shell nested array. The resulting optical assembly weighed >1000 kg, and cost approximately $0.5B. The challenge for future x-ray astronomy missions is to greatly increase the collecting area (by one or more orders of magnitude) while ultimately maintaining sub-arcsecond angular resolution, and all within realistic mass and budget constraints.

Regenerative amplification of single and multiple ultrashort subpicosecond UV pulses in a wide-aperture KrF amplifier with an unstable confocal resonator was investigated on the GARPUN-MTW hybrid laser system. Amplitude-modulated 100-ns long UV radiation pulses with an energy of several tens of joules were obtained at the output of the system. The pulses were a combination of a quasi-stationary oscillation pulse and a train of amplified ultrashort pulses (USPs) with a peak power of 0.2–0.3 TW, which exceeded the power of free-running lasing pulse by three orders of magnitude. The population inversion recovery time in the active KrF laser medium was estimated: τc ≤ 2.0 ns. Trains of USPs spaced at an interval Δt ≈ τc were shown to exhibit the highest amplification efficiency. The production of amplitude-modulated UV pulses opens up the way to the production and maintenance of extended plasma channels in atmospheric air.

Imaging speed is one of the most important parameters that define the performance of optical coherence tomography (OCT) systems. During the last two decades, OCT speed has increased by over three orders of magnitude. New developments in wavelength-swept lasers have repeatedly been crucial for this development. In this review, we discuss the historical evolution and current state of the art of high-speed OCT systems, with focus on wavelength swept light sources and swept source OCT systems.

The rise in demand on the electronic devices and smart solutions is a very important characteristic in today's daily routine. These complicated devices rose with the flourishing of CAD tools and automated digital designs. This paper presents a new standard cell library based on the 7nm BSIM-CMG FinFET technology. The library supports the design of synchronous and asynchronous circuits. Thanks to the new technology, great circuit specs are now reachable. A case study on a 4×16 decoder working at 10 GHz frequency is carried out to verify the feasibility of the proposed library. The study shows enhancement in power in comparison with GF 65nm & UMC 130nm by 66% & 87% respectively, also enhancement in area by three orders of magnitude when compared with GF 65nm & UMC 130nm.

This presentation gives an overview of the neutron experimental facilities at LANSCE. The layout is mentioned in detail, with a map of the south-side experimental facilities, information on Target-4 and the Lujan Center. Then it goes into detail about neutron sources, specifically continuous versus pulsed. Target 4 is then discussed. In conclusion, we have introduced the south-side experimental facilities in operation at LANSCE. 1L target and Target 4 provide complementary neutron energy spectra. Two spallation neutron sources taken together cover more than 11 orders of magnitude in neutron energy.

We introduce the theoretical framework of laser wakefield acceleration and plasma wiggler radiation generation in the matched regime, give scaling laws and apply the scheme to laser systems planned for the near future. We compare the anticipated electron and x-ray beam parameters for a 100 TW, 1 PW and 10 PW short pulse Ti:Sapphire laser with previous experimental results. Depending on the chosen laser configuration, x-rays from a plasma wiggler beamline (PWB) can be several orders of magnitude brighter than current betatron sources, and comparable to or better than 3rd generation synchrotron facilities. Furthermore, increasing the laser power from 0.1 to 10 PW, the spectral peak of the betatron radiation shifts into the hard x-ray and gamma-ray regime. We also discuss a basic layout of a PWB and motivate 100 TW, 1 PW and 10 PW beamlines with a wide range of uses, experiments and applications. The ability to couple the PWBs with various optical laser drivers has the potential to facilitate uses across the spectrum of light source applications. (C) 2011 Elsevier B.V. All rights reserved.

Advances in superconducting linac technology offer the possibility of an upgrade of the Jefferson Lab Free Electron Laser (JLab FEL) facility to an oscillator-based VUV-FEL that would produce 6 × 1012 coherent 100 eV photons per pulse at multi-MHz repetition rates in the fundamental. In this paper we present novel designs that are verified by model calculations which have themselves been validated by comparison with experimental performance measurements using oscillator-based continuous-wave free electron lasers (FELs) operating in the IR and UV, with sub-picosecond pulses up to 75 MHz and producing harmonics upwards of 10 eV. The accelerator uses an energy recovered linac design for efficiency of operation, and high gain per pass in the oscillator. The fully coherent nature of the source results in peak and average brightness values that are several orders of magnitude higher than storage rings.

Accelerator-based light sources stimulated progress in photon science in a truly extraordinary manner. The spectral brightness of storage-ring-based facilities increased by three orders of magnitude every 10 years since the 1960s. The extreme peak brightness at single-pass free electron X-ray lasers with pulse durations variable between about 1 and 300 femtoseconds will allow transformative experiments in many areas of science. This article is an attempt to show how progress in accelerator science and technology stimulated advancement in photon science, by discussing a limited number of examples of work at third generation storage ring facilities and free electron lasers. Hopes for further improvements in specific beam properties are expressed.

We investigated the transmutation of some fission product nuclides (129)l, (135)Cs, (126)Sn, (93)Zr, (107)Pd, (137)Cs and (90)Sr, induced by the Compton backscattering (CBS) photons generated from the future Shanghai Laser Electron Gamma Source (SLEGS) facility. The evaluated photo-transmutation rates for (129)I, (135)CS, (126)Sn, (93)Zr, (107)Pd, (137)CS and (90)Sr can achieve 2.5 x 10(6), 1.3 x 10(6), 4.8 x 10(6), 2.7 x 10(6), 9.4 x 10(6), 1.3 x 10(6) and 1.6 x 10(6) per second, respectively, improving 4-5 orders of magnitude compared with those via the bremsstrahlung photons by a 10(20) W/cm(2) laser. The maximum transmutation Coupling efficiencies of the CBS photons were estimated to be 1.36% for (129)I, 1.70% for (135)Cs, 2.02% for (126)Sn, 1.03% for (90)Zr, 1.52% for (107)Pd. 1.62% for (137)Cs and 1.72% for (90)Sr, which are 2-6 times as those via the bremsstrahlung method by the 10(20) W/cm(2) laser. Moreover, we presented a possible experimental method for the future SLEGS facility to check the estimated results. (C) 2008 Elsevier B.V. All rights reserved.

The ‘Frankfurter Neutronenquelle am Stern–Gerlach–Zentrum’ (FRANZ), which is currently under development, will be the strongest neutron source in the astrophysically interesting energy region in the world. It will be about three orders of magnitude more intense than the well-established neutron source at the Research Center Karlsruhe (FZK).

Proposed laser fusion power plant concepts suffer from the huge size and expense of the lasers needed for compression and ignition. In a 1969 study (classified in 1970 and declassified in 2007), the idea to use chemical high explosives for the pumping of megajoule lasers was explored. Apart from being less expensive by orders of magnitude, such lasers are expected to be much more compact, and with their large energy, output could simultaneously drive several thermonuclear micro-explosion chambers. Because of its topical importance, I accepted the journal's invitation to publish a previously classified work, but with new unpublished ideas, with the previously classified paper put into the appendix.

This article reviews the progress in the development of practical table-top sources of soft x-ray laser radiation. The field is rapidly approaching the stage at which soft x-ray lasers sufficiently compact to fit onto a normal optical table will be routinely utilized in science and technology. This is the result of recent advances in the amplification of soft x-ray radiation in both compact laser-pumped and discharge-pumped devices. The use of excitation mechanisms that take full advantage of new ultrafast high power optical laser drivers and multiple pulse excitation schemes has resulted in the demonstration of saturated soft x-ray amplification at wavelengths as short as 14 nm using several Joule of laser-pump energy. Moreover, several schemes have demonstrated significant gain with only a fraction of a Joule of laser-pump energy. In addition, the demonstration of saturated table-top soft x-ray lasers pumped by very compact capillary discharges has shattered the notion that discharge-created plasmas are insufficiently uniform to allow for soft x-ray amplification, opening a route for the development of efficient, high average power soft x-ray lasers. Recently, a table-top capillary discharge laser operating at 46.9 nm has produced millijoule-level laser pulses at a repetition rate of several Hz, with a corresponding spatially coherent average power per unit bandwidth comparable to that of a beam line at a third generation synchrotron facility. This review summarizes fundamental and technical aspects of table-top soft x-ray lasers based on the generation of population inversions in plasmas, and discusses the present status of development of specific laser systems.

Since the early 1950s the vital multidisciplinary progress in understanding condensed matter is, in a substantial fraction, based on results of neutron scattering experiments. Neutron scattering is an inherently intensity limited method and after 50 years of considerable advance—primarily achieved by improving the scattering instruments—the maturation of the technique of pulsed spallation sources now opens up the way to provide more neutrons with improved cost and energy efficiency. A quantitative analysis of the figure-of-merit of the specialized instruments for pulsed source operation shows that up to 2 orders of magnitude intensity gains can be achieved in the next decade, with the advent of high power spallation sources. The first stations on this road, the MW class short pulse spallation sources SNS in the USA (under commissioning), and J-PARC in Japan (under construction) will be followed by the 5 MW long pulse European Spallation Source (ESS). Further progress, that can be envisaged on the longer term, could amount to as much as another factor of 10 improvement. To cite this article: F. Mezei, C. R. Physique 8 (2007).

We report on a high-contrast, high-peak power laser system, which combines both conventional laser amplification and optical parametric chirped pulse amplification (OPCPA) techniques. By employing an OPCPA system after a regenerative amplifier, we have enhanced the prepulse contrast by six orders of magnitude. A prepulse contrast of better than 4.4 × 10−11 has been measured with a high-energy broadband pulse of 24 mJ at a 10 Hz repetition rate from the OPCPA system. With a subsequent four-pass Ti:sapphire amplifier, we have achieved an amplified energy of 279 mJ and an ultrashort recompressed amplified pulse duration of 23.5 fs. We also discuss the basic design aspects and present our preliminary experimental investigations for higher energy operation to a multijoule.

We report on the frequency doubling of femtosecond laser pulses at 1030 nm center wavelength generated from the fully diode-pumped laser system POLARIS. The newly generated pulses at a center wavelength of 515 nm have a pulse energy of 3 J with a pulse duration of 120 fs. On the basis of initially ultra-high contrast seed pulses we expect a temporal intensity contrast better 10 17 200 ps before the peak of the main pulse. We analyzed the temporal intensity contrast from milliseconds to femtoseconds with a dynamic range covering more than 20 orders of magnitude. The pulses were focussed with a f/2-focussing parabola resulting in a peak intensity exceeding 10 20 W / cm 2 . The peak power and intensity are to the best of our knowledge the highest values for 515 nm-laser-pulses achieved so far.

This year, 2015, marks the centenary of the publication of Einsteins Theory of General Relativity and it has been named the International Year of Light and light-based technologies by the UN General Assembly. It is thus timely to discuss the possibility of broadening the present CERN research program by including a new component based on a novel concept of the light source which could pave a way towards a multipurpose Gamma Factory. The proposed light source could be realized at CERN by using the infrastructure of the existing accelerators. It could push the intensity limits of the presently operating light-sources by at least 7 orders of magnitude, reaching the flux of the order of 10^17 photons/s, in the particularly interesting gamma-ray energy domain of 1 < Ephoton < 400 MeV. This domain is out of reach for the FEL-based light sources. The energy-tuned, quasi-monochromatic gamma beams, together with the gamma-beam-driven, high intensity secondary beams of polarized positrons, polarized muons, neutrons and radioactive ions would constitute the basic research tools of the proposed Gamma Factory. The Gamma Factory could open new research opportunities in a vast domain of uncharted fundamental physics and industrial application territories. It could strengthen the leading role of CERN in the high energy frontier research territory by providing the unprecedented-brilliance secondary beams of polarized muons for the TeV-energy-scale muon collider and the polarized- muon-beam based neutrino factory., An Executive Summary of the Gamma Factory proposal addressed to the CERN management. 6 pages

The EXTraS project (Exploring the X-ray Transient and variable Sky) will harvest the hitherto unexplored temporal domain information buried in the serendipitous data collected by the European Photon Imaging Camera (EPIC) instrument onboard the ESA XMM-Newton X-ray observatory since its launch. This will include a search for fast transients, as well as a search and characterization of variability (both periodic and aperiodic) in hundreds of thousands of sources spanning more than nine orders of magnitude in time scale and six orders of magnitude in flux. X-ray results will be complemented by multiwavelength characterization of new discoveries. Phenomenological classification of variable sources will also be performed. All our results will be made available to the community. A didactic program in selected High Schools in Italy, Germany and the UK will also be implemented. The EXTraS project (2014-2016), funded within the EU/FP7 framework, is carried out by a collaboration including INAF (Italy), IUSS (Italy), CNR/IMATI (Italy), University of Leicester (UK), MPE (Germany) and ECAP (Germany)., 6 pages, 1 figure. Proceedings of "Swift: 10 years of Discovery", to appear in PoS

The APERTIF (APERture Tile In Focus) project aims to install Phased Array Feeds (PAFs) in the 25m diameter reflector antennas of the Westerbork Synthesis Radio Telescope (WSRT). These PAF systems can simultaneously form 37 compound beams on the sky and will replace the current single beam horn feeds. The survey speed of the WSRT will be improved significantly, bringing down the time to execute a deep wide-field astronomical survey by a few orders of magnitude. The detailed design phase is completed and samples of final hardware have been tested (W.A. van Cappellen and J.G. Bij de Vaate, XXXIth URSI GASS, 2014, pp. 1–4). Three WSRT dishes are equipped with this hardware, with the aim to reconfirm system performance, before starting full production.

The design, fabrication and commissioning of a 703.75 MHz SRF photoinjector with a retractable multi-alkali photocathode designed to deliver 0.5 A average current at 100% duty factor is the present undertaking of the electron cooling group in the Collider Accelerator Division of Brookhaven National Labs. This photoinjector represents the state of the art in photoinjector technology, orders of magnitude beyond the presently available technology, and should be commissioned by 2007. The R&D effort presently underway, and the focus of this paper, will address the numerous technological challenges that must be met for this project to succeed. These include the novel physics design of the cavity, the challenges of inserting and operating a multi-alkali photocathode in the photoinjector at these high average currents, and the design and installation of a laser system capable of delivering the required 10 s of watts of laser power needed to make this photoinjector operational.

A new THz/IR/UV photon source at Jefferson Lab is the first of a new generation of light sources based on an Energy-Recovered, (superconducting) Linac (ERL). The machine has a 160 MeV electron beam and an average current of 10 mA in 75 MHz repetition rate hundred femtosecond bunches. These electron bunches pass through a magnetic chicane and therefore emit synchrotron radiation. For wavelengths longer than the electron bunch the electrons radiate coherently a broadband THz ∼ half cycle pulse whose average brightness is >5 orders of magnitude higher than synchrotron IR sources. Previous measurements showed 20 W of average power extracted [Carr, et al., Nature 420 (2002) 153]. The new facility offers simultaneous synchrotron light from the visible through the FIR along with broadband THz production of 100 fs pulses with >200 W of average power. The FELs also provide record-breaking laser power [Neil, et al., Phys. Rev. Lett. 84 (2000) 662]: up to 10 kW of average power in the IR from 1 to 14 μm in 400 fs pulses at up to 74.85 MHz repetition rates and soon will produce similar pulses of 300–1000 nm light at up to 3 kW of average power from the UV FEL. These ultrashort pulses are ideal for maximizing the interaction with material surfaces. The optical beams are Gaussian with nearly perfect beam quality. See www.jlab.org/FEL for details of the operating characteristics; a wide variety of pulse train configurations are feasible from 10 ms long at high repetition rates to continuous operation. The THz and IR system has been commissioned. The UV system is to follow in 2005. The light is transported to user laboratories for basic and applied research. Additional lasers synchronized to the FEL are also available. Past activities have included production of carbon nanotubes, studies of vibrational relaxation of interstitial hydrogen in silicon, pulsed laser deposition and ablation, nitriding of metals, and energy flow in proteins. This paper will present the status of the system and discuss some of the discoveries we have made concerning the physics performance, design optimization, and operational limitations of such a first generation high power ERL light source.