PURPOSE

    The camera is intended for recording and measuring spatial-temporal parameters of high-speed phenomena in the field of soft x-rays radiation in a single-frame mode and a streak mode of sweeping the image under study.
    The image at the camera output is recorded with the aid of a CCD readout unit and is entered into a personal computer. Software provides the user with wide possibilities of processing the image recorded (it is described in details in a documentation of a readout unit).
    Possible fields of application:
   - laser physics
   - nuclear physics
   - plasma physics including thermonuclear synthesis
   - X-ray spectroscopy
   - electrical breakdowns and discharges, etc


CONSTRUCTION AND OPERATING PRINCIPLE

    The main components of the streak camera are:
- PV-204XM open X-ray image converter tube containing a changeable with slit and square from CsJ or Au photocathodes on parylen films or beryllium foil and two pair of deflection plates
- one micro-channel plate(MCP)and phosphor screen
- a power supply unit
- two changeable control unit's (slow and fast) with sweep and gate pulse generators
- a CCD readout unit (1392x1032 pixels, 12 bits ADC)

    These components are assembled within the metal mini case and can be updated. The camera is provided with sealing flange for attaching it to vacuum chambers. The sealing flange is connected with temporal analyzing image converter the tube by means of a bellow.
    An image converter path of the camera is formed by an open (being evacuated during operation) temporal-analyzing image converter tube (ICT) of a PV-204XM type. A readout unit CCD television camera together with a PC forms a digital image-recording system.

    A photosensitive working area of changeable slit Au and CsJ photocathodes is a narrow strip with a 0.1 mm width and a length somewhat greater than 15 mm that in one case is deposited on a very thin substrate from nitrocellulose (parylene) and in the other case is deposited on a substrate from beryllium foil of a 15 ?m thickness. Both substrates are transparent for soft X-rays. A photocathode-strip is vertically oriented. Only that part of the image that is projected on the photocathode is converted into an electron image that falls on the photosensitive strip.
    A photosensitive working area of changeable frame Au and CsJ photocathodes on substrates from beryllium foil is a square of a size not less than 8 mm x 8 mm.

    X-ray radiation (or a projected X-ray process image) recorded by the camera is converted into an electron image on an ICT photocathode, is accelerated by a photocathode-accelerating electrode electrical field, is accelerated and focused on an MCP input surface by an electric field of an electrostatic lens. The electron image intensified in the MCP by at least a factor of 5 x 103 is transferred to a luminescent screen where it is converted into a visible image. The MCP allows to provide such image brightness on the ICT screen that is necessary for reliable record of the ICT output image with the CCD readout unit.

    Image gain (a conversion coefficient) can be adjusted by changing a voltage on the MCP.
    With the aid of an objective lens the visible image is transferred from the ICT screen to the television camera (TVC) CCD matrix, is readout, digitized and transmitted to PC system unit memory for subsequent processing and displaying. The TVC is power-supplied from the PC.
    Controlling electronics including power supply unit (PSU), shut pulse generator (ShPG) and sweep pulse generator (SwPG) provides ICT operation in a static (continuous) or dynamic (pulsed, waiting) mode.
    In a static mode of X-rays camera operation ICT and TVC works in continuous mode, an object image coming to the ICT input is continuously displayed on the PC display.

    In dynamic mode of X-rays camera operation the MCP is blanked if there is no pulse of camera triggering. Therefore, there is no image on the ICT screen. When a triggering pulse is applied to the camera control unit (CU), then the SwPG forms a linearly varying sweep voltage, the ShPG generates a rectangular pulse that unblanks the MCP for the time of a direct sweep pass and TVC records to the PC an image which was registered on the ICT screen. On completion of a direct sweep pass the MCP is blanked by the ShPG.
    The camera complete set contains two changeable control units: CU-1 (fast) and CU-2 (slow).
    A mode of X-rays camera operation (either single-frame or streak) depends on whether the SwPG is disconnected with ICT deflection plates or is connected to them. In the first case a single-frame ("FRAME") mode is realized; in the second case a streak ("STREAK") mode is realized.


Main parameters