[en] The challenge of the high accuracy of certain optical measurements, the long coherence length of light provokes one to search for possibilities to enlarge the neutron coherence length. A proposal is made to achieve this by using a five or a four plate Bonse-Hart interferometer. A further problem is, whether the neutron beam is composed of wave packets or of overlapping independent monochromatic waves; it is considered that the former is more likely. (author) 12 refs.; 3 figs

[en] Some problems of the interaction of slow singly and multiply charged ions with surfaces are described; in particular the neutralization processes which happen a few Angstroms in front of the surface are studied. The stepwise neutralization in a sequence of Auger-de-excitation and Auger-neutralization processes for doubly charged neon ions is demonstrated in detail. (Author)

[en] Fractions of long-lived excited species in noble-gas ion beams, produced by various methods, have been determined using slow ion impact induced electron emission from clean polycrystalline tungsten. Investigations with ion beams produced by single electron impact on atoms permitted the determination of cross sections for the production of singly charged metastable ions of the noble gases Ar, Kr and Xe. The cross sections obtained increase steeply from threshold up their maximum values of about 10^-17 cm² within 1.5 times threshold energy. Processes responsible for production of these metastable ions are discussed and the method applied is compared with other techniques for metastable ion detection. (author)

No abstract available

[en] High intensity electron beams are usually produced by thermionic cathodes. For applications where increased energy spread is tolerable the use of plasma cathodes can advantageous. In the present paper the dependence of beam qualities can discharge parameters for a Duoplasmatron electron gun is investigated. With extraction potentials of 1 to 10 kV a maximum current density of 7 A cm^-2 with a total current of 0.5 A can be produced. The measured microperveances are in the region of 0.5 to 3. (author)

[en] In the potential emission process an electron transfers from a bound state in the metal to a vacant state of the incoming projectile. This report discusses potential emission of electrons due to impact of multiply charged ions (MCI). From experimental results it can be concluded that: Neutralization of slow MCI takes place in the vicinity of the surface in a stepwise manner. The yield of the emitted electrons is proportional to the potential energy up to a critical velocity which depends on the available potential energy. The proportionality factor is a function of impact energy and decreases with increasing velocity. Inner shell vacancies in the projectile give rise to emission of high energetic characteristic projectile Auger electrons and cause a deviation of the proportionality between potential energy and electron yield. Target Auger electrons caused by projectile inner shell holes have also been observed. 19 refs.; 5 figs

[en] Some problems of the interaction of slow singly and multiply charged ions with surfaces are described; in particular the neutralization processes which happen a few Angstroms in front of the surface are studied. The stepwise neutralization in a sequence of Auger-de-excitation and Auger-neutralization processes for doubly charged neon ions end is demonstrated in detail. (Auth.)

No abstract available

[en] The determination of cross-sections for desorption of CO adsorbed on a Ni(111) single crystal induced by argon ion bombardment is discussed. Experimental results are given for ions with kinetic energies ranging from 10 to 600 eV. The desorption cross-sections and the fractions of neutrals and ions desorbed from the surface were measured by means of a quadrupole mass spectrometer. In addition, the influence of the charge state of the impinging ion on the desorption cross-section has been studied. (author)

[en] Results from sputtering of TaC and TiC by various ions ranging from Xe⁺ to H⁺ are presented. Different effects of preferential sputtering show up in the surface concentration of TaC and TiC due to bombardment with various ions. For TaC mainly mass effects are important whereas binding energy and particularly chemical effects are found in TiC. (G.Q.)