RU2474813C1 - Broadband soft x-ray spectrometer - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: broadband soft X-ray spectrometer has a sealed housing in which there are detection channels, each having, arranged in series on the direction of radiation, an entrance slit, a selective filter, a region bounded by two total external reflection (TER) mirrors and an X-ray detector, wherein the detection channels are arranged quasi-parallel, wherein the TER mirrors are merged into one bundle by a common housing; the entrance slit is common for the whole bundle, and the X-ray detector used is a photographic recorder or a CCD matrix.

EFFECT: high spectral selectivity of the device, easier operation of the spectrometer owing to interdependent adjustment of the detection channels of the spectrometer on the radiation source, and compactness of the device and reduced weight and size due to fewer fastening elements.

3 cl, 5 dwg

Description

The invention relates to devices for determining the spatial spectral characteristics of x-rays generated by plasma formations, x-ray sources with a wide spectral range, and can be used in scientific and applied problems, for example, in the field of thermonuclear research or in the development of x-ray sources for lithographic systems, etc. .P.

Known x-ray spectrometer [Patent RU 2177629, "X-ray spectrometer", IPC: G01T 1/36, publ. 12/27/2001, authors: Shalata F.G., Elyash S.L. et al.], including a two-part composite housing, selective edge X-ray filters located in through cells and fixed with a pressure plate, and X-ray recorders in the form of thermoluminescent detectors mounted on plugs. The presented spectrometer is used to measure the spectral characteristics or spatial distribution of x-rays in a given region of the spectrum. The signal is generated using a selective edge filter and detector.

The disadvantage of this device is the inability to determine the spatial brightness of the radiation source due to the lack of a system of image reprojection and low spectral selectivity due to the presence of the contribution from quanta with energy above the transmission window of the edge filter in the detector signal.

The closest in technical solution to the claimed device is a broadband soft x-ray spectrometer ["DMX: An absolutely calibrated time-resolved broadband soft x-ray spectrometer designed for MJ class laser-produced plasmas", JLBourgade, B. Villette, JLBocher and others, Review of scientific instruments, Vol.72, No.1, Jan 2001, p.1173-1182], which is selected as a prototype and includes a sealed enclosure in which 12 registration channels are radially placed, each of which consists of a collimating slit, two mirrors of total external reflection (AA), a selective edge filter located in a through cell in front of the air defense mirrors, and an X-ray detector located at the output of the registration channel. The X-ray radiation recorder is a vacuum X-ray diode (WFD). The spectrometer is used to measure the spectral-temporal characteristics of x-rays. The formation of a temporary signal is provided due to the WFD, and the separation of radiation into spectral components is carried out by air defense mirrors and selective edge filters.

The disadvantage of the prototype are:

- the impossibility of registering the spatial brightness of the x-ray source due to the lack of an image re-projection scheme and the use of the WFD, which does not allow recording the spatial distribution;

- insufficient spectral selectivity of the channels due to a single reflection of x-ray radiation from the air defense mirrors;

- difficulty in operation, requiring the configuration of each registration channel separately;

- high overall dimensions.

The problem to be solved is the creation of a new spectrometer design for obtaining information on the spectral brightness of an x-ray source at its various spatial points in the range of quantum energies from 0.05 keV to 12 keV with one-dimensional spatial resolution.

The technical result consists in providing the possibility of obtaining the spatial spectral characteristics of the glow of the x-ray source.

An additional technical result is to increase the spectral selectivity of the device; ensuring the convenience of operation of the spectrometer due to the interdependent alignment of the registration channels of the spectrometer to the radiation source; the compactness of the device and the reduction of overall dimensions by reducing the number of fasteners.

The technical result is achieved in that the broadband soft x-ray spectrometer includes a sealed housing in which registration channels are located, each of which includes an entrance slit sequentially placed in the direction of radiation, a selective filter, an area bounded by two mirrors of total external reflection ), and an X-ray recorder.

What is new is that the registration channels are placed quasi-parallel, while the air defense mirrors are combined into a package by a common body, the entrance slit is common to the entire package, and a photorecorder or CCD array is used as an X-ray registrar. In addition, the device may additionally contain a zero registration channel, and a sealed enclosure can be attached to the interaction chamber.

The placement of the registration channels quasi-parallel allows the x-ray radiation to experience multiple reflections in the region bounded by two air defense mirrors, which increases the spectral selectivity of the channels; and also use only one slit to register a one-dimensional spatial spectral image.

The combination of air defense mirrors in a package with a common housing makes it possible to register a one-dimensional image of an x-ray source from one spatial position; reduces the dimensions of the structure, providing ease of use due to the interdependent alignment of the channels.

The presence of a common entrance slit for the entire package carries out the construction of a one-dimensional image of the x-ray source on the recorder, provides ease of use and improves overall dimensions.

The use of a photorecorder or a CCD matrix as an X-ray recorder allows one to obtain registration of the spatial distribution of the spectral brightness of the source.

Additional supply of the device with a zero registration channel allows you to do without additional systems for alignment, which reduces the weight and dimensions of the device.

Attaching a sealed enclosure to the interaction chamber improves the usability by facilitating the alignment of the device.

The design of a broadband soft x-ray spectrometer is shown in Fig. 1, where 1 is an x-ray source, 2 is x-ray, 3 is an entrance slit, 4 are holders of selective edge filters, 5 are selective edge filters, 6 are combined into an air defense mirror package, 7 - X-ray recorder, 8 - zero registration channel, 9 - common housing, 10 - sealed housing, 11 - interaction chamber, 12 - holder with shifts.

Figure 2 shows the spectral characteristics of the channels of the device; figure 3 shows a model of a complex laser-plasma source, consisting of two plasma sources, spaced in space; figure 4 shows the resulting spectrogram using a film of the brand UV-4; figure 5 presents the restored spectral brightness of the upper and lower x-ray sources.

In the presented embodiment, the device includes a sealed cylindrical-shaped vacuum housing made of stainless steel, which is vacuum tightly attached to the interaction chamber in which the x-ray source is placed. In a sealed enclosure located in the direction of radiation: the entrance slit, consisting of two steel knives with a thickness of 200 μm and a gap of 20 μm between them; selective filters (including edge K-, L-type) glued to the filter holder, which, in turn, is mounted on a common aluminum housing, in which air defense mirrors made of flat window glass obtained by hot spill over the surface of molten tin; and an X-ray recorder. Air defense mirrors are located quasi-parallel in a common housing at the required specific angle. For the simultaneous adjustment of all air defense mirrors, an additional registration channel, also located in the package, was additionally used. The common housing is attached to the sealed with a holder with slides. An X-ray film cassette UV-4 is used as an X-ray recorder, with which a source image is obtained. The cassette is attached using the pressure plates to the exit of the package. The package itself, placed inside the sealed enclosure, is attached to the holder with slides, which allows the package to be tilted in two mutually perpendicular planes to angles of up to 10 degrees.

The device operates as follows. The spectrometer is attached to the interaction chamber 11, in which the x-ray source 1 is located. The distances between the x-ray source 1, the input slit 3 and the x-ray detector 7 are selected so as to provide the necessary spatial resolution. Air defense mirrors 6 are located in a common housing 9 in such a way as to provide the specified angles of incidence of x-ray radiation 2 on them, for the implementation of spectral selection. A zero registration channel 8 is installed in the common housing 9, for subsequent alignment of the entire package of air defense mirrors 6. The common housing 9 is adjusted using a holder with slides 12 so that the x-ray quanta emitted from the central region of the x-ray source 1 pass through the entrance slit 3 and reflected from the air defense mirrors 6, they would fall into the central region of the X-ray recorder 7. By selecting the thicknesses of the filters 5 mounted on the holder 4, the required energy densities of the X-ray radiation 2 are obtained t he area X-ray recorder 7 for each channel. When the installation of the device and its adjustment are completed, the cover of the sealed housing 10 closes. In the case of using 7 films as a registrar of X-ray radiation, after the experiment, the cover of the sealed housing 10 opens, and the film changes in the cartridge. Using the received signals from the X-ray recorder 7, a spatial spectral dependence of the brightness distribution of the x-ray source 1 is constructed.

Design study was carried out and a spectrometer was created. As a result of experimental studies, the spatial and spectral characteristics of a laser plasma, a Z-pinch plasma, and a high-current X-ray tube were obtained. The recorded spectral range is from 60 eV to 12 keV. The spectral width of each channel is E / ΔE≈5. Using the device, a one-dimensional spatial image of a laser-plasma source with a resolution of 20 μm was obtained. Currently, the developed device is successfully used in the process of studying plasma parameters and, due to its compactness, facilitates its use in various application conditions.

Claims (3)

1. A broadband soft x-ray spectrometer, including a sealed enclosure, in which registration channels are located, each of which includes an entrance slit sequentially placed in the direction of radiation, a selective filter, an area bounded by two mirrors of total external reflection (AA), and an X-ray recorder radiation, characterized in that the registration channels are placed quasi-parallel, while the air defense mirrors are combined into a package by a common housing, the entrance slit is common to the entire package , and as a registrar of x-ray radiation use a photorecorder, or a CCD matrix. 2. The broadband spectrometer according to claim 1, characterized in that it is additionally equipped with a zero recording channel. 3. The broadband spectrometer according to claim 1, characterized in that the sealed enclosure is attached to the interaction chamber.

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