IPAC2011 - List of Authors (Papadichev, V.A.)

Paper	Title	Page
WEPZ005	Field Calculations to obtain Attosecond/Femtosecond Electron Bunches	2772
	V.A. Papadichev LPI, Moscow, Russia
	Obtaining short electron bunches of attosecond and femtosecond duration in a combined quasi-static and laser electric field [* - ***] requires careful field formation in the cathode region. First, the maximum of laser electric field normal to the cathode plate, depending on the incidence angle, was found employing Fresnel formulae using complex dielectric permittivity of metals. Second, laser field enhancement on cathode spikes was calculated for the case of an ellipsoid in a qusi-static approximation (laser wavelength larger than spike dimensions). Field enhancement is approximately proportional to the square of the ratio of major to minor axes of ellipsoid. Thus, enhancement factors as large as 100 - 1000 are obtainable, allowing to reduce laser power by 10 thousand to 1 million times. V.A.Papadichev, Patent RU 2 269 877 C1, 10.02.06, Bull. 4. V.A.Papadichev, Proc. EPAC08, p.2812. * V.A.Papadichev, Proc. EPAC08, p.2815. **** V.A.Papadichev, Proc. IPAC'10, p. 4372

WEPZ006	Forming Attosecond Electron Pulses in Space-charge Dominated Regime	2775
	V.A. Papadichev LPI, Moscow, Russia
	Production of high-current attosecond electron pulses requires studying of the final bunching stage, which inevitably is space-charge dominated [, , *]. Two models are studied, both allow solving a one-dimensional equation of motion. The first is for a spherical bunch, which corresponds to a short emitted pulse from a one-spike cathode of diameter approximately equal to its length. The second model is suited for pulses emitted from a multi-spike or multi-blade cathode. The bunch in the latter case is a thin plate and its evolution can be studied by also solving one-dimensional equation of motion. It was shown that bunches of 10-attosecond (as) duration with peak current of dozens of amperes can be obtained when using a carbon dioxide laser and less than 0.1-as duration with currents up to 1 MA when employing a neodymium laser. Beam focusing in transverse directions is also studied using a model. Possible applications of such electron bunches are reviewed, including obtaining attosecond pulses of tunable coherent radiation in UV and X-ray regions. V.A.Papadichev, Proceedings of EPAC08, p.2815. V.A.Papadichev, Proceedings of IPAC'10, Kyoto, Japan, p. 4372. * V.A.Papadichev, Proc. RUPAC-2010, TUPSAO10, p. 56.

Paper

Title

Page

Field Calculations to obtain Attosecond/Femtosecond Electron Bunches

2772

V.A. Papadichev
LPI, Moscow, Russia

Obtaining short electron bunches of attosecond and femtosecond duration in a combined quasi-static and laser electric field [* - ****] requires careful field formation in the cathode region. First, the maximum of laser electric field normal to the cathode plate, depending on the incidence angle, was found employing Fresnel formulae using complex dielectric permittivity of metals. Second, laser field enhancement on cathode spikes was calculated for the case of an ellipsoid in a qusi-static approximation (laser wavelength larger than spike dimensions). Field enhancement is approximately proportional to the square of the ratio of major to minor axes of ellipsoid. Thus, enhancement factors as large as 100 - 1000 are obtainable, allowing to reduce laser power by 10 thousand to 1 million times.
* V.A.Papadichev, Patent RU 2 269 877 C1, 10.02.06, Bull. 4.
** V.A.Papadichev, Proc. EPAC08, p.2812.
*** V.A.Papadichev, Proc. EPAC08, p.2815.
**** V.A.Papadichev, Proc. IPAC'10, p. 4372

WEPZ006

Forming Attosecond Electron Pulses in Space-charge Dominated Regime

2775

V.A. Papadichev
LPI, Moscow, Russia

Production of high-current attosecond electron pulses requires studying of the final bunching stage, which inevitably is space-charge dominated [*, **, ***]. Two models are studied, both allow solving a one-dimensional equation of motion. The first is for a spherical bunch, which corresponds to a short emitted pulse from a one-spike cathode of diameter approximately equal to its length. The second model is suited for pulses emitted from a multi-spike or multi-blade cathode. The bunch in the latter case is a thin plate and its evolution can be studied by also solving one-dimensional equation of motion. It was shown that bunches of 10-attosecond (as) duration with peak current of dozens of amperes can be obtained when using a carbon dioxide laser and less than 0.1-as duration with currents up to 1 MA when employing a neodymium laser. Beam focusing in transverse directions is also studied using a model. Possible applications of such electron bunches are reviewed, including obtaining attosecond pulses of tunable coherent radiation in UV and X-ray regions.
* V.A.Papadichev, Proceedings of EPAC08, p.2815.
** V.A.Papadichev, Proceedings of IPAC'10, Kyoto, Japan, p. 4372.
*** V.A.Papadichev, Proc. RUPAC-2010, TUPSAO10, p. 56.