Final published version
Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
}
TY - JOUR
T1 - High harmonics from relativistically oscillating plasma surfaces - a high brightness attosecond source at keV photon energies
AU - Zepf, M.
AU - Dromey, B.
AU - Kar, S.
AU - Bellei, C.
AU - Carroll, D. C.
AU - Clarke, R. J.
AU - Green, J. S.
AU - Kneip, S.
AU - Markey, K.
AU - Nagel, S. R.
AU - Simpson, P. T.
AU - Willingale, L.
AU - McKenna, P.
AU - Neely, D.
AU - Najmudin, Z.
AU - Krushelnick, K.
AU - Norreys, P. A.
PY - 2007/11/15
Y1 - 2007/11/15
N2 - An intense laser pulse interacting with a near discontinuous plasma vacuum interface causes the plasma surface to perform relativistic oscillations. The reflected laser radiation then contains very high order harmonics of fundamental frequency and-according to current theory-must be bunched in radiation bursts of a few attoseconds duration. Recent experimental results have demonstrated x-ray harmonic radiation extending to 3.3 angstrom (3.8 keV, order n > 3200) with the harmonic conversion efficiency scaling as eta(n) n(-2.5) over the entire observed spectrum ranging from 17 nm to 3.3 angstrom. This scaling holds up to a maximum order, n(RO) 81 8(1/2)gamma(3), where gamma is the peak value of the Lorentz factor, above which the harmonic efficiency decreases more rapidly. The coherent nature of the generated harmonics is demonstrated by the highly directional beamed emission, which for photon energy h nu > 1 keV is found to be into a cone angle similar to 4 degrees, significantly less than that of the incident laser cone (20 degrees).
AB - An intense laser pulse interacting with a near discontinuous plasma vacuum interface causes the plasma surface to perform relativistic oscillations. The reflected laser radiation then contains very high order harmonics of fundamental frequency and-according to current theory-must be bunched in radiation bursts of a few attoseconds duration. Recent experimental results have demonstrated x-ray harmonic radiation extending to 3.3 angstrom (3.8 keV, order n > 3200) with the harmonic conversion efficiency scaling as eta(n) n(-2.5) over the entire observed spectrum ranging from 17 nm to 3.3 angstrom. This scaling holds up to a maximum order, n(RO) 81 8(1/2)gamma(3), where gamma is the peak value of the Lorentz factor, above which the harmonic efficiency decreases more rapidly. The coherent nature of the generated harmonics is demonstrated by the highly directional beamed emission, which for photon energy h nu > 1 keV is found to be into a cone angle similar to 4 degrees, significantly less than that of the incident laser cone (20 degrees).
KW - LASER-PULSE
KW - INTENSE LASER
KW - GENERATION
KW - ULTRASHORT
KW - SUPPRESSION
U2 - 10.1088/0741-3335/49/12B/S14
DO - 10.1088/0741-3335/49/12B/S14
M3 - Journal article
VL - 49
SP - B149-B162
JO - Plasma Physics and Controlled Fusion
JF - Plasma Physics and Controlled Fusion
SN - 0741-3335
IS - 12B
T2 - 34th European-Physical-Society Conference on Plasma Physics
Y2 - 2 July 2007 through 6 July 2007
ER -