Lobster-eye Optics Research Articles

Effective algorithm for ray-tracing simulations of lobster eye and similar reflective optical systems

The algorithm presented is intended mainly for lobster eye optics. This type of optics (and some similar types) allows for a simplification of the classical ray-tracing procedure that requires great many rays to simulate. The method presented performs the simulation of a only few rays; therefore it is extremely effective. Moreover, to simplify the equations, a specific mathematical formalism is used. Only a few simple equations are used, therefore the program code can be simple as well. The paper also outlines how to apply the method to some other reflective optical systems.

Exploring the Dynamic X-ray Universe: Scientific Opportunities for the Einstein Probe Mission

Time-domain astrophysics will enter a golden era towards the end of this decade with the advent of major facilities across the electromagnetic spectrum and in the multi-messenger realms of gravitational wave and neutrino. In the soft X-ray regime, the novel micro-pore lobster-eye optics provides a promising technology to realise, for the first time, focusing X-ray optics for wide-angle monitors to achieve a good combination of sensitivity and wide field of view. In this context Einstein Probe, a soft X-ray all-sky monitor mission, was proposed and selected as a candidate mission of priority in the space science programme of the Chinese Academy of Sciences. This paper reviews the most important science developments and key questions in this field towards 2020 and beyond, and how to achieve them technologically. It also introduces the Einstein Probe mission, including its key science goals and mission definition, as well as some of the key technological issues.

Invited Article: First flight in space of a wide-field-of-view soft x-ray imager using lobster-eye optics: Instrument description and initial flight results.

We describe the development, launch into space, and initial results from a prototype wide field-of-view soft X-ray imager that employs lobster-eye optics and targets heliophysics, planetary, and astrophysics science. The sheath transport observer for the redistribution of mass is the first instrument using this type of optics launched into space and provides proof-of-concept for future flight instruments capable of imaging structures such as the terrestrial cusp, the entire dayside magnetosheath from outside the magnetosphere, comets, the Moon, and the solar wind interaction with planetary bodies like Venus and Mars [Kuntz et al., Astrophys. J. (in press)].

Prototyping a global soft X‐ray imaging instrument for heliophysics, planetary science, and astrophysics science

AbstractWe describe current progress in the development of a prototype wide field‐of‐view soft X‐ray imager that employs Lobster‐eye optics and targets heliophysics, planetary, and astrophysics science. The prototype will provide proof‐of‐concept for a future flight instrument capable of imaging the entire dayside magnetosheath from outside the magnetosphere. Such an instrument was proposed for the ESA AXIOM mission (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Next-Generation X-Ray Astronomy

AbstractThis review of future timing capabilities in X-ray astronomy includes missions in implementation (astro-h, gems, srg and astrosat), those under study (currently nicer, athena and loft), and new technologies that may be the seeds for future missions, such as lobster-eye optics. Those missions and technologies will offer exciting new capabilities that will take X-ray Astronomy into a new generation of achievements.

Erratum: “Investigation of etched silicon wafers for lobster-eye optics” [Rev. Sci. Instrum. 70, 1268 (1999)

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Tests of lobster eye optics for small space X-ray telescope

The Lobster eye design for a grazing incidence X-ray optics provides wide field of view of the order of many degrees, for this reason it can be a convenient approach for the construction of space all-sky X-ray monitors. We present preliminary results of tests of prototype lobster eye X-ray optics in quasi parallel beam full imaging mode conducted using the 35 m long X-ray beam-line of INAF-OAPA in Palermo (Italy). X-ray images at the focal plane have been taken with a microchannel plate (MCP) detector at several energy values from 0.3 to 8 keV. The gain, the field of view and the angular resolution have been measured and compared with theoretical values.

Kirkpatrick-Baez (KB) and Lobster Eye (LE) Optics for Astronomical and Laboratory Applications

Most of grazing incidence (reflective) X-ray imaging systems used in astronomy and in other (laboratory) applications are based on the Wolter 1 (or modified) arrangement. But there were proposed also other designs and configurations, which are considered for future applications for both in laboratory and (finitely) in space. The Kirkpatrick-Baez (KB) lenses as well as various types of Lobster-Eye (LE) optics and MCP/Micropore optics serve as an example. Analogously to Wolter lenses, the X-rays are mostly reflected twice in these systems to create focal images. The KB systems have already found wide usage in laboratory and synchrotron, both application are reviewed and discussed in detail in this paper. While this paper focuses on future possible applications of non-Wolter grazing incidence systems in space and astronomy, we also discuss in detail applications in other areas of science, where (in contrary to astronomy) some of these systems have demonstrated their advantages.

Detailed simulation of a Lobster-eye telescope

The concept of an x-ray telescope based on the optics of the eye of certain types of crustacea has been in currency for nearly thirty years. However, it is only in the last decade that the technology to make the telescope and the opportunity to mount it on a suitable space platform have combined to allow the idea to become a reality. Accordingly, we have undertaken a detailed simulation study, updating previous simplified models, to properly characterise the performance of the instrument in orbit. The study reveals details of how the particular characteristics of the lobster-eye optics affect the sensitivity of the instrument and allow us to implement new ideas in data extraction methods.

MC ray-tracing optimization of lobster-eye focusing devices with RESTRAX

The enhanced functionalities of the latest version of the RESTRAX software, providing a high-speed Monte Carlo (MC) ray-tracing code to represent a virtual three-axis neutron spectrometer, include representation of parabolic and elliptic guide profiles and facilities for numerical optimization of parameter values, characterizing the instrument components. As examples, we present simulations of a doubly focusing monochromator in combination with cold neutron guides and lobster-eye supermirror devices, concentrating a monochromatic beam to small sample volumes. A Levenberg–Marquardt minimization algorithm is used to optimize simultaneously several parameters of the monochromator and lobster-eye guides. We compare the performance of optimized configurations in terms of monochromatic neutron flux and energy spread and demonstrate the effect of lobster-eye optics on beam transformations in real and momentum subspaces.

Production issues for high aspect ratio Lobster-eye optics using LIGA

We have previously considered some of the parameters for, and production issues involved in making, a useful Lobster-eye prototype using X-ray lithography. Due to the high aspect ratio and dense packing of the array features, we were unable, in our initial attempts to produce optimal Lobster-eye optics using X-ray lithography and a PMMA resist, to consistently overcome adhesion issues between the substrate and the resist. In recent work we have overcome this problem by using SU-8 as the resist instead. In the light of this advance we reconsider the relevant parameters and production issues when using SU-8 and lower-energy exposures.

Using lobster-eye optics in hard-x-ray imaging systems

Using lobster-eye optics in hard-x-ray imaging systems

Production issues for high aspect ratio Lobster-eye optics using LIGA

Production issues for high aspect ratio Lobster-eye optics using LIGA

Deconvolution of an extended object viewed by a lobster-eye telescope

X-ray telescopes based on the lobster-eye principle offer considerable promise for an all-sky monitor mission. The extended cruciform point-spread function of the lobster-eye optic has typically not been a major issue as sources in the classical X-ray band (0.5–3.5 keV) at the sensitivities that will be observed are generally point-like and well separated. However, lobster-eye optics may also be used as the basis for an imaging spectrometer for near-earth objects. Such a mission requires that the effect of the lobster-eye point spread function be considered. This paper finds that deconvolution of the point-spread function is feasible at contrast levels as low as 10% for a reasonable orbital configuration and mission duration.

Investigation of etched silicon wafers for lobster-eye optics

We investigate some high aspect ratio etched silicon to determine its suitability as a lobster-eye optic. The major defects present leading to performance degradation are identified and tolerance goals are set for prospective candidates.

Lobster-eye all-sky monitors: A comparison of one- and two-dimensional designs

X-ray all-sky monitors (ASMs) have played a vital role in the development of x-ray astronomy. In order for them to continue to do so ASMs with high sensitivity, broad energy band coverage, and large sky coverage will be required. The best way to achieve these goals is for the next generation of ASMs to have focusing capability. Lobster-eye optics offer a way to construct a focusing ASM and a design is presented for a lobster-eye ASM that offers an order of magnitude increase in sensitivity over previous nonfocusing instruments. Simpler versions of the lobster-eye telescope, based on arrays of flat reflectors in one dimension only, have also been suggested in the past. In this article we compare the one- and two-dimensional (lobster-eye) configurations and conclude that, for intense short-lived phenomena, where the background is negligible, the one-dimensional configuration is optimal, whereas for ultimate sensitivity of background-limited faint sources the two-dimensional configuration is preferred.

Lobster-eye x-ray optics: a rapid evaluation of the image distribution

A method for calculating the image distribution for one-dimensional lobster-eye optics is presented. This method gives the image distribution exactly for certain cases and offers improved speed over the method of ray tracing. Examples of the use of the algorithm are given. We show that the algorithm gives the same results as detailed ray-tracing codes. Extension of the method to the two-dimensional case is discussed.

X-ray focusing with lobster-eye optics: a comparison of theory with experiment

We report an experimental investigation and comparison with simulation of the x-ray focusing of a flat, square profile microchannel plate. We use x rays with an energy of ~1.5 keV from a laser-produced plasma. The images were recorded with x-ray film. We find the focal structure to be consistent with theoretical expectations. The angular resolution of the focus is 0.96 mrad, which is a major improvement over previous results. The measured peak intensity gain is 27 ± 4, which is ~33% of that for a perfect optic.