Bremsstrahlung emission profile from intense laser-solid interactions as a function of laser focal spot size

C. D. Armstrong; C. M. Brenner; E. Zemaityte; G. G. Scott; D. R. Rusby; G. Liao; H. Liu; Y. Li; Z. Zhang; Y Zhang; B. Zhu; P. Bradford; N. C. Woolsey; P. Oliveira; C. Spindloe; W. Wang; P. McKenna; D. Neely

doi:10.1088/1361-6587/aaf596

Bremsstrahlung emission profile from intense laser-solid interactions as a function of laser focal spot size

C. D. Armstrong, C. M. Brenner, E. Zemaityte, G. G. Scott, D. R. Rusby, G. Liao, H. Liu, Y. Li, Z. Zhang, Y Zhang, B. Zhu, P. Bradford, N. C. Woolsey, P. Oliveira, C. Spindloe, W. Wang, P. McKenna, D. Neely

Physics

Research output: Contribution to journal › Article › peer-review

Abstract

The bremsstrahlung x-ray emission profile from high intensity laser-solid interactions provides valuable insight to the internal fast electron transport. Using penumbral imaging, we characterise the spatial profile of this bremsstrahlung source as a function of laser intensity by incrementally increasing the laser focal spot size on target. The experimental data shows a dual-source structure; one from the central channel of electrons, the second a larger substrate source from the recirculating electron current. The results demonstrate than an order of magnitude improvement in the intensity contrast between the two x-ray sources is achieved with a large focal spot, indicating preferable conditions for applications in radiography. An analytical model is derived to describe the transport of suprathermal electron populations that contribute to substrate and central channel sources through a target. The model is in good agreement with the experimental results presented here and furthermore is applied to predict laser intensities for achieving optimum spatial contrast for a variety of target materials and thicknesses.

Original language	English
Article number	034001
Number of pages	9
Journal	Plasma Physics and Controlled Fusion
Volume	61
Issue number	3
DOIs	https://doi.org/10.1088/1361-6587/aaf596
Publication status	Published - 23 Jan 2019

Keywords

bremsstrahlung
defocus
laser-plasma
penumbral
x-ray radiography
x-ray source size

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10.1088/1361-6587/aaf596

Armstrong_2019_Plasma_Phys._Control._Fusion_61_034001
© 2019 IOP Publishing Ltd
Final published version, 1.39 MBLicence: CC BY

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Armstrong, C. D., Brenner, C. M., Zemaityte, E., Scott, G. G., Rusby, D. R., Liao, G., Liu, H., Li, Y., Zhang, Z., Zhang, Y., Zhu, B., Bradford, P., Woolsey, N. C., Oliveira, P., Spindloe, C., Wang, W., McKenna, P., & Neely, D. (2019). Bremsstrahlung emission profile from intense laser-solid interactions as a function of laser focal spot size. Plasma Physics and Controlled Fusion, 61(3), Article 034001. https://doi.org/10.1088/1361-6587/aaf596

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title = "Bremsstrahlung emission profile from intense laser-solid interactions as a function of laser focal spot size",

abstract = "The bremsstrahlung x-ray emission profile from high intensity laser-solid interactions provides valuable insight to the internal fast electron transport. Using penumbral imaging, we characterise the spatial profile of this bremsstrahlung source as a function of laser intensity by incrementally increasing the laser focal spot size on target. The experimental data shows a dual-source structure; one from the central channel of electrons, the second a larger substrate source from the recirculating electron current. The results demonstrate than an order of magnitude improvement in the intensity contrast between the two x-ray sources is achieved with a large focal spot, indicating preferable conditions for applications in radiography. An analytical model is derived to describe the transport of suprathermal electron populations that contribute to substrate and central channel sources through a target. The model is in good agreement with the experimental results presented here and furthermore is applied to predict laser intensities for achieving optimum spatial contrast for a variety of target materials and thicknesses.",

keywords = "bremsstrahlung, defocus, laser-plasma, penumbral, x-ray radiography, x-ray source size",

author = "Armstrong, {C. D.} and Brenner, {C. M.} and E. Zemaityte and Scott, {G. G.} and Rusby, {D. R.} and G. Liao and H. Liu and Y. Li and Z. Zhang and Y Zhang and B. Zhu and P. Bradford and Woolsey, {N. C.} and P. Oliveira and C. Spindloe and W. Wang and P. McKenna and D. Neely",

year = "2019",

month = jan,

day = "23",

doi = "10.1088/1361-6587/aaf596",

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Armstrong, CD, Brenner, CM, Zemaityte, E, Scott, GG, Rusby, DR, Liao, G, Liu, H, Li, Y, Zhang, Z, Zhang, Y, Zhu, B, Bradford, P , Woolsey, NC, Oliveira, P, Spindloe, C, Wang, W, McKenna, P & Neely, D 2019, 'Bremsstrahlung emission profile from intense laser-solid interactions as a function of laser focal spot size', Plasma Physics and Controlled Fusion, vol. 61, no. 3, 034001. https://doi.org/10.1088/1361-6587/aaf596

TY - JOUR

T1 - Bremsstrahlung emission profile from intense laser-solid interactions as a function of laser focal spot size

AU - Armstrong, C. D.

AU - Brenner, C. M.

AU - Zemaityte, E.

AU - Scott, G. G.

AU - Rusby, D. R.

AU - Liao, G.

AU - Liu, H.

AU - Li, Y.

AU - Zhang, Z.

AU - Zhang, Y

AU - Zhu, B.

AU - Bradford, P.

AU - Woolsey, N. C.

AU - Oliveira, P.

AU - Spindloe, C.

AU - Wang, W.

AU - McKenna, P.

AU - Neely, D.

PY - 2019/1/23

Y1 - 2019/1/23

N2 - The bremsstrahlung x-ray emission profile from high intensity laser-solid interactions provides valuable insight to the internal fast electron transport. Using penumbral imaging, we characterise the spatial profile of this bremsstrahlung source as a function of laser intensity by incrementally increasing the laser focal spot size on target. The experimental data shows a dual-source structure; one from the central channel of electrons, the second a larger substrate source from the recirculating electron current. The results demonstrate than an order of magnitude improvement in the intensity contrast between the two x-ray sources is achieved with a large focal spot, indicating preferable conditions for applications in radiography. An analytical model is derived to describe the transport of suprathermal electron populations that contribute to substrate and central channel sources through a target. The model is in good agreement with the experimental results presented here and furthermore is applied to predict laser intensities for achieving optimum spatial contrast for a variety of target materials and thicknesses.

AB - The bremsstrahlung x-ray emission profile from high intensity laser-solid interactions provides valuable insight to the internal fast electron transport. Using penumbral imaging, we characterise the spatial profile of this bremsstrahlung source as a function of laser intensity by incrementally increasing the laser focal spot size on target. The experimental data shows a dual-source structure; one from the central channel of electrons, the second a larger substrate source from the recirculating electron current. The results demonstrate than an order of magnitude improvement in the intensity contrast between the two x-ray sources is achieved with a large focal spot, indicating preferable conditions for applications in radiography. An analytical model is derived to describe the transport of suprathermal electron populations that contribute to substrate and central channel sources through a target. The model is in good agreement with the experimental results presented here and furthermore is applied to predict laser intensities for achieving optimum spatial contrast for a variety of target materials and thicknesses.

KW - bremsstrahlung

KW - defocus

KW - laser-plasma

KW - penumbral

KW - x-ray radiography

KW - x-ray source size

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DO - 10.1088/1361-6587/aaf596

M3 - Article

AN - SCOPUS:85062520295

SN - 0741-3335

VL - 61

JO - Plasma Physics and Controlled Fusion

JF - Plasma Physics and Controlled Fusion

IS - 3

M1 - 034001

ER -

Bremsstrahlung emission profile from intense laser-solid interactions as a function of laser focal spot size

Abstract

Keywords

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