Spherical Crystal X-ray Imaging for MTW, OMEGA, and OMEGA EP

Transcription

1 Spherical Crystal X-ray Imaging for MTW, OMEGA, and OMEGA EP C.STOECKL, G. FISKEL, R. K. JUNGQUIST, P. M. NILSON, AND W. THEOBALD University of Rochester, Laboratory for Laser Energetics Spherical Crystal Imaging (SCI) Systems Have Been Installed on MTW, OMEGA and OMEGA EP A 5-nm Resolution is Predicted for the Cu K a Imaging System The OMEGA EP Crystal Imager Uses Two TIM s in Shot Mode and Three TIM s in Alignment Mode The OMEGA Spherical Crystal Imager is Based on the OMEGA EP Design Using Two Opposing TIM s High-Quality Backlit Images of Implosions can be Obtained with a Crystal Imaging System An SCI system has a number of unique capabilities narrow spectral width high throughput high spatial resolution SCI systems have been installed on all of the LLE laser facilities MTW: Cu K a and Zr K a emission, Al He b and Si He a backlighting OMEGA EP: Cu K a emission OMEGA: Cu K a emission, Si He a backlighting Three major improvements are planned for the Si-SCI on OMEGA aspheric crystal to reduce the astigmatism time-resolved recording system using an x-ray framing camera (XRFC) fast target insertion system for compatibility with CRYO E % to 90% width (nm) E18862a Y direction; sphere X direction; sphere Paraxial focusing D radius (mm) Best focusing N Crystal Detector TIM-13 TIM-10 TIM-12 Alignment fiber The crystal is located in TIM mm from the target at a 1.3 angle of incidence The IP detector in TIM-13 is placed at 2.7 m from crystal for a magnification of ~9.5 E20907 C. Stoeckl et al., Rev. Sci. Instrum. 83, (2012). E20912 Spherical crystal imager TIM-6 TIM-4 Line-of-sight blocker The crystal is located in TIM-6, 267 mm from the target at a 1.3 angle of incidence The IP detector in TIM-4 is placed 3.6 m from the crystal for a magnification of ~13 Image plate Detector The backlighter foil is not in the focus of the imaging system, so the backlighter uniformity does not depend on the laser-intensity distribution A collimator blocks the line-of-sight (LOS) to the backlighter, minimizing the background from short-pulse laser A direct LOS block shields the detector from background produced by the implosion target E20916 Collimator Direct LOS block Short-pulse laser Target Backlighter Crystal A Spherical Crystal Imager Can Work Either in Self-emission or Backlighting Mode The Spherical Crystal Imager on MTW Uses a Manual Crystal Mount and Either CCD or IP Detectors The Crystal Holder Assembly Includes a Removable Blast shield and a Direct Line-of-Sight Shield A Pointer on the Crystal Mount Assembly is Used to Locate the Crystal at the Desired Distance from TCC The OMEGA SCI Setup was Recently Modified to a Si He a Backlighting Configuration Near-normal incidence Large field of view Low astigmatism Aim to obtain high spatial resolution of ~5 nm or better High-intensity laser pulse Backlighter Top view not to scale Self-emission Object Bragg angle (i B ) Detector CCD or IP Extension pipe 10 magnification 2750 mm 275 mm Removable crystal shield Tungsten sight shield blocker (7 mm OD) Crystal New Focus 8817-V with ipico Motor drive Pointer Thumb screws Locating pins New base for the vacuum-rated Newport motorized mount Updated the grab handles on the x-ray block assembly Relocated the x-ray collimators Spherically bent crystal Crystal mount Larger-diameter shield Detector E18857a Rowland circle E18860a E20909 E20913 E20917 Different Crystals Are Used for the Different Wavelength Requirements of the Applications Wedge Targets Are Used to Study the Fast-Electron Conversion Efficiency The Image-Plate Detector Assembly is Based on a LLNL Design with an Additional Collimator and Filter Mount The Image Plate Detector is Housed in an Extension on the Back of TIM-4 Backlit Images of Implosions were Recorded with the Si-SCI System at 2.2 ns Emission line Si He a Cu K a Zr K a Front view Laser-beam spot Side view 45º, s-pol Bragg diffraction imager (BDI) Access door 30-mm aperture s64959 SCI mm aperture s65000 SCI 1 25 Wavelength (Å) Energy (kev) Quartz Reflection order E-field 105 nm 30º, s-pol 18 nm 110 nm Image plate New front end 30-mm ID collimator and additional filter Image-plate assembly Alignment camera 200 nm nm Bragg angle (º) One-piece Cu targets with ~ nm 3 volume and 30º, 45º, and 60º opening angles Radius of curvature (~1 nm) smaller than the focal-spot diameter Wedge target orientation sets laser polarization Image plate The astigmatism of the imager is reduced with the smaller aperture. 0 E18859a E17223a E20910 E20914 E20918 Two Imagers Have Been Fabricated by Photonics Product Group, Inc. A Spherical Bragg Crystal Imager Recorded the Spatially Resolved Cu K a Emission The First Data from the OMEGA EP SCI Showed High Resolution and a Good Signal/Background The SCI Recorded Images from Cu-Doped, Cone-in-Shell Fast-Ignitor Targets A Reasonable Contrast is Obtained even with a Time- Integrated Recording System R = 500 mm Flat foil Wedge 100 nm 100 nm nm 3 Cu target 1 kj, 10 ps, best focus Edge lineouts at different locations Image rotated and scaled s65000 SCI 1 Lineout: Three-column average s65000 lineout 30 mm Quartz crystal is 100 nm thick and 25 mm in diameter The crystal is optically bound to a glass substrate that is spherically shaped to R = 500 mm The substrate is 10 mm thick and 30 mm in diameter One imager will be used on OMEGA EP and another on OMEGA 2125 Homogeneous emission; indicates hot-electron refluxing in the targets. CCD 2117 s-pol, 60 8-keV K a fluor Bragg crystal y (nm) x (nm) 500 Signal/background ~100 Intensity (arbitrary units) nm Distance across edge (nm) Spatial resolution ~10nm ``` 900 nm Cu-doped shell OMEGA UV beams only Undoped shell OMEGA UV beams only 200 nm Signal (arbitrary units) Radius (nm) Laser E20906 E17224a E20911 E20915 Images courtesy of M. Wei, General Atomics E20919

2 Spherical Crystal Imaging (SCI) Systems Have Been Installed on MTW, OMEGA and OMEGA EP An SCI system has a number of unique capabilities narrow spectral width high throughput high spatial resolution SCI systems have been installed on all of the LLE laser facilities MTW: Cu K a and Zr K a emission, Al He b and Si He a backlighting OMEGA EP: Cu K a emission OMEGA: Cu K a emission, Si He a backlighting Three major improvements are planned for the Si-SCI on OMEGA aspheric crystal to reduce the astigmatism time-resolved recording system using an x-ray framing camera (XRFC) fast target insertion system for compatibility with CRYO E20905

3 A Spherical Crystal Imager Can Work Either in Self-emission or Backlighting Mode Near-normal incidence Large field of view Low astigmatism Aim to obtain high spatial resolution of ~5 nm or better High-intensity laser pulse Backlighter Top view not to scale Self-emission Object Bragg angle (i B ) Spherically bent crystal Detector E18857a Rowland circle

4 Different Crystals Are Used for the Different Wavelength Requirements of the Applications Emission line Si He a Cu K a Zr K a Wavelength (Å) Energy (kev) Quartz Reflection order Bragg angle (º) E18859a

5 Two Imagers Have Been Fabricated by Photonics Product Group, Inc. R = 500 mm Quartz crystal is 100 nm thick and 25 mm in diameter The crystal is optically bound to a glass substrate that is spherically shaped to R = 500 mm The substrate is 10 mm thick and 30 mm in diameter 30 mm One imager will be used on OMEGA EP and another on OMEGA E20906

6 A 5-nm Resolution is Predicted for the Cu K a Imaging System 20 10% to 90% width (nm) Y direction; sphere X direction; sphere Paraxial focusing Best focusing D radius (mm) E18862a

7 The Spherical Crystal Imager on MTW Uses a Manual Crystal Mount and Either CCD or IP Detectors Detector CCD or IP 2750 mm Extension pipe 10 magnification 275 mm Crystal mount E18860a

8 Wedge Targets Are Used to Study the Fast-Electron Conversion Efficiency Front view Side view Laser-beam spot 45º, s-pol E-field 105 nm 18 nm 110 nm 30º, s-pol One-piece Cu targets with ~ nm 3 volume and 30º, 45º, and 60º opening angles Radius of curvature (~1 nm) smaller than the focal-spot diameter Wedge target orientation sets laser polarization E17223a

9 A Spherical Bragg Crystal Imager Recorded the Spatially Resolved Cu K a Emission Flat foil Wedge 100 nm 100 nm s-pol, 60 Homogeneous emission; indicates hot-electron refluxing in the targets. CCD 8-keV K a fluor Bragg crystal Laser E17224a

10 The OMEGA EP Crystal Imager Uses Two TIM s in Shot Mode and Three TIM s in Alignment Mode N TIM-10 The crystal is located in TIM mm from the target at a 1.3 angle of incidence Crystal TIM-12 The IP detector in TIM-13 is placed at 2.7 m from crystal for a magnification of ~9.5 Alignment fiber Detector TIM-13 E20907 C. Stoeckl et al., Rev. Sci. Instrum. 83, (2012).

11 The Crystal Holder Assembly Includes a Removable Blast shield and a Direct Line-of-Sight Shield Removable crystal shield Tungsten sight shield blocker (7 mm OD) Crystal New Focus 8817-V with ipico Motor drive E20909

12 The Image-Plate Detector Assembly is Based on a LLNL Design with an Additional Collimator and Filter Mount Bragg diffraction imager (BDI) Image plate New front end 30-mm ID collimator and additional filter E20910

13 The First Data from the OMEGA EP SCI Showed High Resolution and a Good Signal/Background nm 3 Cu target 1 kj, 10 ps, best focus Edge lineouts at different locations 50 y (nm) Intensity (arbitrary units) nm x (nm) Distance across edge (nm) Signal/background ~100 Spatial resolution ~10nm E20911

14 The OMEGA Spherical Crystal Imager is Based on the OMEGA EP Design Using Two Opposing TIM s TIM-4 Spherical crystal imager Image plate TIM-6 Line-of-sight blocker The crystal is located in TIM-6, 267 mm from the target at a 1.3 angle of incidence E20912 The IP detector in TIM-4 is placed 3.6 m from the crystal for a magnification of ~13

15 A Pointer on the Crystal Mount Assembly is Used to Locate the Crystal at the Desired Distance from TCC Thumb screws Locating pins Pointer E20913

16 The Image Plate Detector is Housed in an Extension on the Back of TIM-4 Access door Image-plate assembly Alignment camera Image plate E20914

17 The SCI Recorded Images from Cu-Doped, Cone-in-Shell Fast-Ignitor Targets ``` 900 nm Cu-doped shell OMEGA UV beams only Undoped shell OMEGA UV beams only E20915 Images courtesy of M. Wei, General Atomics

18 High-Quality Backlit Images of Implosions can be Obtained with a Crystal Imaging System Short-pulse laser Crystal Detector Collimator Direct LOS block Target Backlighter The backlighter foil is not in the focus of the imaging system, so the backlighter uniformity does not depend on the laser-intensity distribution A collimator blocks the line-of-sight (LOS) to the backlighter, minimizing the background from short-pulse laser A direct LOS block shields the detector from background produced by the implosion target E20916

19 The OMEGA SCI Setup was Recently Modified to a Si He a Backlighting Configuration Updated the grab handles on the x-ray block assembly New base for the vacuum-rated Newport motorized mount Relocated the x-ray collimators Larger-diameter shield E20917

20 Backlit Images of Implosions were Recorded with the Si-SCI System at 2.2 ns 30-mm aperture s64959 SCI mm aperture s65000 SCI nm nm 5 0 The astigmatism of the imager is reduced with the smaller aperture. E20918

21 A Reasonable Contrast is Obtained even with a Time- Integrated Recording System Image rotated and scaled s65000 SCI 1 Lineout: Three-column average s65000 lineout nm Signal (arbitrary units) Radius (nm) E20919