| 1. |
- Alcorn, J, et al.
(författare)
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Basic instrumentation for Hall A at Jefferson Lab
- 2004
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - : Elsevier BV. - 0167-5087 .- 0168-9002. ; 522:3, s. 294-346
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Tidskriftsartikel (refereegranskat)abstract
- The instrumentation in Hall A at the Thomas Jefferson National Accelerator Facility was designed to study electro-and photo-induced reactions at very high luminosity and good momentum and angular resolution for at least one of the reaction products. The central components of Hall A are two identical high resolution spectrometers, which allow the vertical drift chambers in the focal plane to provide a momentum resolution of better than 2 x 10(-4). A variety of Cherenkov counters, scintillators and lead-glass calorimeters provide excellent particle identification. The facility has been operated successfully at a luminosity well in excess of 10(38) CM-2 s(-1). The research program is aimed at a variety of subjects, including nucleon structure functions, nucleon form factors and properties of the nuclear medium. (C) 2003 Elsevier B.V. All rights reserved.
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| 2. |
- S. Zamith, V. Blanchet, B. Girard, J. Norin, J. Mauritsson, A. l'Huillier, J. Andersson, S. L. Sorensen, I. Hjelte, O. Björneholm and D. Gauyacq
(författare)
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The predissociation of highly excited states in acetylene by time-resolved photoelectron spectroscopy
- 2003
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Ingår i: Journal of Chemical Physics. ; :119, s. 3763-
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Tidskriftsartikel (refereegranskat)
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| 3. |
- Descamps, D, et al.
(författare)
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Extreme ultraviolet interferometry measurements with high-order harmonics
- 2000
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Ingår i: Optics Letters. - 0146-9592. ; 25:2, s. 135-137
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Tidskriftsartikel (refereegranskat)abstract
- We demonstrate that high-order harmonics generated by short, intense laser pulses in gases provide an interesting radiation source for extreme ultraviolet interferometry, since they are tunable, coherent, of short pulse duration, and simple to manipulate. Harmonics from the 9th to the 15th are used to measure the thickness of an aluminum layer. The 11th harmonic is used to determine the spatial distribution of the electron density of a plasma produced by a 300-ps laser. Electronic densities higher than 2-10(20) electrons/cm(3) are measured. (C) 2000 Optical Society of America. OCIS codes: 190.0190, 190.4160, 190.7110, 120.3180, 140.7240, 350.4500.
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| 4. |
- Gayou, O, et al.
(författare)
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Measurement of G(Ep)/G(Mp) in (e)over-right-arrowp -> e(p)over-right-arrow to Q(2)=5.6 GeV2
- 2002
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Ingår i: Physical Review Letters. - 1079-7114. ; 88:9
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Tidskriftsartikel (refereegranskat)abstract
- The ratio of the electric and magnetic form factors of the proton G(Ep)/G(Mp), which is an image of its charge and magnetization distributions, was measured at the Thomas Jefferson National Accelerator Facility (JLab) using the recoil polarization technique. The ratio of the form factors is directly proportional to the ratio of the transverse to longitudinal components of the polarization of the recoil proton in the elastic (e) over right arrowp --> e (p) over right arrow reaction. The new data presented span the range 3.5 < Q(2) < 5.6 GeV2 and are well described by a linear Q(2) fit. Also, the ratio rootQ(2) F-2p/F-1p reaches a constant value above Q(2) = 2 GeV2.
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| 5. |
- Merdji, H., et al.
(författare)
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Coherence properties of high-order harmonics : Application to high-density laser-plasma diagnostic
- 2000
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Ingår i: Laser and Particle Beams. - 0263-0346. ; 18:3, s. 495-502
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Tidskriftsartikel (refereegranskat)abstract
- We present two interferometry schemes in the extreme ultraviolet, based on either the wave-front division of a unique harmonic beam (1st scheme) or two spatially separated, phase-locked harmonic sources (2nd scheme). In the first scheme using a Fresnel bimirror interferometer, we measure the degree of spatial coherence of the 13 th harmonic generated in xenon, as a function of different parameters. A high degree of coherence, larger than 0.5, is found for the best conditions in almost the full section of the beam. Then, we demonstrate that the second scheme can be used for interferometry measurements with an ultrahigh time resolution. The 11th harmonic is used to study the spatial variation of the electron density of a laser-produced plasma. Electronic densities higher than 2.10 20 cm -3 are measured.
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| 6. |
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| 7. |
- Tcherbakoff, O., et al.
(författare)
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Controlling the duration of XUV high order harmonic pulses
- 2003
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Ingår i: 2003 Conference on Lasers and Electro-Optics Europe, CLEO/EUROPE 2003. - 0780377346 - 9780780377349
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Konferensbidrag (refereegranskat)abstract
- We modulate temporally the polarization of a ∼ 30 fs, 800 nm IR pulse and use it to generate high order harmonics. The harmonic emission can clearly be confined and the XUV pulse duration can be continuously tuned from - 5 - 7 fs to 50 fs.
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| 8. |
- Biegert, Jens, et al.
(författare)
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Control of the frequency chirp rate of high harmonic pulses
- 2004
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Ingår i: Springer Series in Chemical Physics. - 0172-6218. ; 79, s. 204-206
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Tidskriftsartikel (refereegranskat)abstract
- We measured the frequency chirp rate of harmonics 13 to 23 in argon by cross-correlation with a short femtosecond probe pulse. We directly measured the negative chirp due to the atomic dipole phase and demonstrated that an additional chirp on the pump pulse was transferred to the qth harmonic as q times the fundamental chirp.
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| 9. |
- Lopez, Rodrigo, et al.
(författare)
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Characterization of high-order harmonic radiation on femtosecond and attosecond time scales
- 2004
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Ingår i: Applied Physics B. - : Springer Science and Business Media LLC. - 0946-2171 .- 1432-0649. ; 78:7-8, s. 835-840
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Tidskriftsartikel (refereegranskat)abstract
- We characterize the temporal structure of high-order harmonic radiation on both the femtosecond and attosecond time scales. The harmonic emission is characterized by mixed-color two-photon ionization with an infrared femtosecond laser using a Mach-Zehnder interferometer where both pump and probe arms travel completely separate paths. In a first experiment, we measure the duration and chirp of individual harmonics. In a second experiment, we resolve, for the first time with this type of setup, the attosecond beating of several harmonics generated under conditions similar to the first experiment. We suggest that the results of both measurements can be combined to determine the full attosecond time structure of the harmonic emission.
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| 10. |
- Mauritsson, Johan, et al.
(författare)
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Measurement and control of the frequency chirp rate of high-order harmonic pulses
- 2004
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Ingår i: Physical Review A (Atomic, Molecular and Optical Physics). - 1050-2947. ; 70:2
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Tidskriftsartikel (refereegranskat)abstract
- We measure the chirp rate of harmonics 13 to 23 in argon by cross correlation with a 12 femtosecond probe pulse. Under low ionization conditions, we directly measure the negative chirp due to the atomic dipole phase, and show that an additional chirp on the pump pulse is transferred to the qth harmonic as q times the fundamental chirp. Our results are in accord with simulations using the experimentally measured 815 nm pump and probe pulses. The ability to measure and manipulate the harmonic chirp rate is essential for the characterization and optimization of attosecond pulse trains.
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