The Ramaty High Energy Solar Spectroscopic Imager (RHESSI) Xray data base (February 2002 – May 2006) has been searched to find solar flares with weak thermal components and flat photon spectra. Using a regularised inversion technique, we determine the mean electron flux distribution from count spectra of a selection of events with flat photon spectra in the 15–20 keV energy range. Such spectral...

Extensive confJggtion interaction calculations bilsed on ab initio wavefunctions including cliffme basis functions are reported for all-?rans-1,3,5-hex Using these results we have assigned the one-photon s_oectra of Gavin and Rice and the electron-impact spectra of Kuppermann, and we have confirmed the assignment of the two-photon spectra of El-8ayed. The valence 2 ’ Ag state is found to lie ab...

Articles you may be interested in Single-photon and resonance-enhanced multiphoton threshold ionization of the allyl radical Single-photon threshold photoionization spectra for jet-cooled NO have been measured for the v+ =0 and 1 vibrational levels of the X I~+ ground state of NO+. The NO+ rotational state distribution for the v+ =0 level is shown to be perturbed by nearby autoionizing levels, ...

In an effort to elucidate the variation of the electronic structure as a function of oxidation and composition, we investigated an extensive series of dichromium oxide clusters, Cr2On- (n=1-7), using photoelectron spectroscopy (PES). Well-resolved PES spectra were obtained at several photon energies. While low photon energy spectra yielded much better spectral resolution, high photon energy dat...

INTRODUCTION We directly measured diagnostic X-ray photon spectra produced by a single-phase 2-pulse diagnostic X-ray unit driven at 50 to 100 kV and a few mA(1), a mammographic X-ray unit at 25 to 32 kV and 3 times of 80 mAs(2) and an X-ray computed tomography (CT) scanner at 120 kV and 3 mA(3) have been analyzed. Since detected spectra were distorted by the response of CdZnTe(CZT) detector an...

The influence of the pulse shape and/or chirp on multipeak structures that appear in both photoelectron spectra in laser-induced autoionisation and in near-resonant Ramanscattering photon spectra is investigated. The analytic results are presented for both types of spectra for a wide variety of smooth strong pulses. Possible experimental verification of the multipeak structures in the spectra i...

We present gas-phase infrared spectra of tantalum cluster cations containing 6-20 atoms. Infrared multiple photon dissociation of their complexes with argon atoms is used to obtain vibrational spectra in the region between 90 and 305 cm(-1). Many spectra have features in common with the vibrational spectra of the lighter homologs, vanadium and niobium, pointing to a common cluster growth mechan...

Effect of radiation of many photons by a single electron traversing a target is discussed. When the summary energy of emitted photons (the energy losses spectrum) is measured only, the photon spectrum is distorted comparing with the photon spectrum in one interaction. Influence of this effect is discussed for the cases (1) bremsstrahlung (described by Bethe-Heitler formula), (2) the strong Land...

Recent progress in solar Hard X-ray (HXR) observations with RHESSI data and methods for spectral inversion allow us to study model-independent mean electron flux spectra in solar flares. We report several hard X-ray events observed by RHESSI in which the photon spectra I(ǫ) are such that the inferred source mean electron spectra are not consistent with the standard model of collisional transpor...

In this article we derive the lineshapes observed in two-photon photoassociation spectrocopy of molecules using an effective Hamiltonian adapted from previous work in atomic physics. The lineshape is decomposed in terms of sums and products of Breit-Wigner and Fano profiles, which we associate with physical absorption and emission processes, and to quantum interferences between transition ampli...