Magnetic bottle

Handschuh H, Gantefor G and Eberhardt W 1995 Vibrational spectroscopy of clusters using a magnetic bottle electron spectrometer Rev. Sci. Instnim. 66 3838... 

TRPES has been recently reviewed and details of the experimental method and its interpretation can be found elsewhere [5], Trans-azobenzene was introduced via a helium supersonic molecular beam into the interaction region of a magnetic bottle photoelectron spectrometer. The molecules were photoexcited by a tunable femtosecond laser pulse (pump pulse) with a wavelength of 280-350nm. After a variable time delay, the excited molecules were ionized by a second femtosecond laser pulse (probe pulse) with a wavelength of 200 or 207nm. The emitted photoelectrons were collected as a function of pump-probe time delay and electron kinetic energy. 

The experiments were carried out in a high vacuum chamber where a beam of atomic potassium K (4s) intersects perpendicularly with the femtosecond laser pulses leading to photoionization. The released photoelectrons are detected employing a magnetic bottle time-of-flight electron spectrometer. The 785 nm, 30 fs FWHM laser pulses provided by an amplified 1 kHz Ti sapphire laser system are split into two beams using a Mach-Zehnder interferometer. In the first experiment the time delay r is varied in a range of 80 to 100 fs with 0.2 fs resolution at a... 

Storage has mainly been achieved in four types of traps (11 the radio frequency or Paul trap (2) the Penning trap (3) the Kingdon electrostatic trap and (4) the magnetostatic (magnetic bottle) trap. The principles, advanlages, and disadvantages of these traps are detailed by DJ. Wineland (Science, 226, 395-400, Oct. 26, 1984). 

Figure 13. Magnetic trapping of ions in a magnetic bottle as a function of mass.

A commonly used analyzer in TRPES experiments has been the magnetic bottle time-of-flight (TOF) spectrometer [118-120], This technique uses a... 

Photoionization always produces two species available for analysis the ion and the electron. By measuring both photoelectrons and photoions in coincidence, the kinetic electron may be assigned to its correlated parent ion partner, which may be identified by mass spectrometry. The extension of the photoelectron-photoion-coincidence (PEPICO) technique to the femtosecond time-resolved domain was shown to be very important for studies of dynamics in clusters [131, 132]. In these experiments, a simple yet efficient permanent magnet design magnetic bottle electron spectrometer was used for photoelectron... 

Photoelectron Analysers. Electrostatic, TOF, magnetic bottle and threshold electron analysers have all been used. The electrostatic analysers, which are similar to those in the classical PES set-up, have the advantage of an optimized design and ready commercial availability. The electron energy is a function of the analyser voltage, and the resolution... 

Major components of a tokamak fusion reactor are shown here. Giant coils of superconducting metal create powerful magnetic fields that confine the superhot plasma—a hot gas of charged particles—in a magnetic bottle. ... 

C. Energetic Electron Pair Analysis Magnetic Bottle TOF Methods... 

The structure of this chapter is as follows. First, a brief review of the characteristics of direct double ionization of atoms is presented as a background to the recent results on indirect processes and on molecules. Second, the new experimental methods based on threshold electron detection and on the magnetic bottle time of flight (TOF) technique are described. The main body of the chapter then presents representative results on selected atoms and molecules. Finally the relevance of the experimental findings to the characterization of electron correlation is discussed qualitatively. 

The combination of magnetic bottle spectrometers with synchrotron radiation from storage rings has opened a huge energy range but also posed a problem. 

Another unusual type of highly excited doubly charged ion has one hole in a deep inner shell and one in the valence shell. Such states are of interest theoretically because of (a) the presence of distinct electron vacancies and (b) several possible pathways for their production [86]. The first observation of direct formation of such states in Ne and N2 was recently achieved by the magnetic bottle TOF method [87]. The cross section for their formation is very low, and the electron distribution in the Ne case shows both a direct contribution and an indirect pathway. For the final states from s l2p l ionization the intermediate states are satellites of the Islsi1 3S)ns series whose lines show asymmetric Fano profiles. The presence of these profiles demonstrates that the matrix elements representing direct double ionization, formation of the intermediate states, and interaction of those states with the continuum are of similar magnitudes. 

The advantage of the magnetic bottle TOF-PEPECO technique relative to classical Auger spectroscopy, that it allows separate examination of the Auger... 

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