Mikael Otendal

Liquid-metal-jet anode electron-impact x-ray source

We demonstrate an anode concept, based on a liquid-metal jet, for improved brightness in compact electron-impact x-ray sources. The source is demonstrated in a proof-of-principle experiment where a 50 keV, ∼100 W electron beam is focused on a 75 μm liquid-solder jet. The generated x-ray flux and brightness is quantitatively measured in the 7–50 keV spectral region and found to agree with theory. Compared to rotating-anode sources, whose brightness is limited by intrinsic thermal properties, the liquid-jet anode could potentially be scaled to achieve a brightness >100× higher than current state-of-the-art sources. Applications such as mammography, angiography, and diffraction would benefit from such a compact high-brightness source.

Liquid-tin-jet laser-plasma extreme ultraviolet generation

We demonstrate the applicability of liquid-metal jets in vacuum as regenerative targets for laser-plasma generation of extreme ultraviolet (EUV) and soft x-ray radiation. This extends the operation ...

Phase-contrast x-ray imaging with a liquid-metal-jet-anode microfocus source

Phase-contrast methods increase contrast, detail, and selectivity in x-ray imaging. Present compact x-ray sources do not provide the necessary spatial coherence with sufficient power to allow the laboratory-scale high-resolution phase-contrast imaging with adequate exposure times. In this letter, the authors demonstrate phase-contrast imaging with few-micron detail employing a compact ∼6.5μm spot liquid-metal-jet-anode high-brightness microfocus source. The 40W source is operated at more than ten times higher electron-beam power density than present microfocus sources and is shown to provide sufficient spatial coherence as well as scalability to high power, thereby enabling the application of phase-contrast x-ray imaging with short exposure times in clinics and laboratories.

A 9 keV electron-impact liquid-gallium-jet x-ray source

We demonstrate a high-brightness compact 9 keV electron-impact microfocus x-ray source based on a liquid-gallium-jet anode. A approximately 30 W, 50 kV electron gun is focused onto the approximately 20 ms, 30 mum diameter liquid-gallium-jet anode to produce an approximately 10 microm full width at half maximum x-ray spot. The peak spectral brightness is >2 x 10(10) photons(s mm(2) mrad(2)x0.1% BW). Calculation and experiments show potential for increasing this brightness by approximately three orders of magnitude, making the source suitable for laboratory-scale x-ray crystallography and hard x-ray microscopy.

Liquid-metal-jet anode x-ray tube

We describe a novel electron-impact x-ray source based on a high-speed liquid-metal-jet anode. Thermal power load calculations indicate that this new anode concept potentially could increase the achievable brightness in compact electron-impact x-ray sources by more than a factor 100 compared to current state-of-the-art rotating-anode or microfocus sources. A first, successful, low-power proof-of-principle experiment is described and the feasibility of scaling to high-brightness and high-power operation is discussed. Some possible applications that would benefit from such an increase in brightness are also briefly described.

Stability and debris in high-brightness liquid-metal-jet-anode microfocus x-ray sources

We investigate the x-ray spot stability and the debris emission in liquid-metal-jet anode electron-impact x-ray sources operating in the 10-100 W microfocus regime. The x-ray spot size is 15-23 mu ...

Liquid-metal-jet x-ray tube technology and tomography applications

The power and brightness of electron-impact micro-focus X-ray sources have long been limited by thermal damage in the anode. Here we describe a novel X-ray microfocus source based on a new anode concept, the liquid-metal-jet anode (MetalJet). The regenerative nature of this anode allows for significantly higher e-beam power density than on conventional anodes, resulting in this source generating significantly higher brightness than other X-ray tubes in the microfocus regime (~5-50 μm). We describe the fundamental properties of the technology and will review the current status specifically in terms of spot size, stability, lifetime, flux, acceleration voltage and brightness.

Laboratory x-ray micro imaging: Sources, optics, systems and applications

We summarize the recent progress in laboratory-scale soft and hard x-ray micro imaging in Stockholm. Our soft x-ray work is based on liquid-jet laser-plasma sources which are combined with diffractive and multilayer optics to form laboratory x-ray microscopes. In the hard x-ray regime the imaging is based on a liquid-metal-jet electron-impact source which provides the necessary coherence to allow phase-contrast imaging with high fidelity.

Status of the liquid-metal-jet-anode electron-impact x-ray source

We have demonstrated a new electron-impact hard-x-ray source based on a liquid-metal-jet anode in a proof-of-principle experiment. Initial calculations show that this new anode concept potentially allows a >100x increase in source brightness compared to todays compact hard-x-ray sources. In this paper we report on the scale up of the system to medium electron-beam power resulting in a brightness comparable to current state-of-the-art sources. The upgraded system combines a ~20-μm diameter liquid-tin jet operating at ~60 m/s with a 50 kV, 600 W electron beam focused to ~150 μm FWHM. We describe the properties of the current system, experimental results, as well as a brief discussion of key issues for future high-power scaling.

High-intensity electron beam for liquid-metal-jet anode hard x-ray generation

We report on our progress towards the experimental realization of a liquid-metal-jet-anode x-ray source with high brightness. We have previously shown that this electron-impact source has potential for very high x-ray brightness by combining small-spot high-flux operation of the electron beam with high-speed operation of the regenerative liquid-metal-jet anode. In the present paper we review the system and describe theoretical calculations for improving the 50 kV, 600 W electron-beam focussing to ~30 μm spot size. With such a system the power density on the liquid-metal-jet would be ~400 kW/mm2, i.e., more than an order of magnitude higher than the power density on a state-of-the-art rotating anode.