## 1 Introduction  
The development of free-electron lasers (FEL) has enabled novel studies into the structure and dynamics of various forms of matter under extreme conditions, ranging from atoms and molecules [1; 2; 3; 4] to condensed matter [5; 6; 7]. A particular interesting research field is the ultrafast dynamics of nanoscale samples triggered by intense FEL pulses, which provide basic insights into the mechanism of the laser-matter interaction. Atomic clusters are an ideal model system for this research. Their size is tunable and they are isolated systems with bulk density. The properties and responses of clusters in intense fields have been widely studied experimentally--using methods including charged-particle spectroscopy [8; 9; 10; 11; 12; 13; 14; 15; 16; 17], X-ray diffraction [18; 19; 20; 21; 22; 23; 24; 25; 26], and fluorescence spectroscopy [27; 28]--as well as theoretically [29; 30; 31; 32].  
Early experimental studies started with ion spectrometry, from which, unexpected energetic ion emissions, even in the short wavelength (extreme ultraviolet to X-ray) regime, were reported [9]. This stimulated discussion regarding the dynamics in clusters based on the spectra obtained by averaging over the ensemble of shots of the incident laser pulses. Pioneering works [18; 22; 33; 34] revealed that the properties of individual particles are concealed by the accumulation of spectra due to the laser profile and to the size distribution and structural isomers of clusters originating from the generation methods.  
X-ray free-electron laser (XFEL) sources provide a new pathway for the analysis of the structure of single particles. Intense and short X-ray pulses delivered from XFELs allow for the investigation of the structure of nanoscale samples and biomolecules [35; 36] in the particle-by-particle regime, based on the diffraction before destruction scheme [37]. The structural analysis of free-flying clusters has been demonstrated by single-shot diffraction experiments [18; 19; 20; 21; 23; 24; 22]. The combination of single-shot imaging with spectroscopy allows for the studies of the laser-matter interaction, where experimental parameters such as the size and structure of the single particle target and the intensity of the irradiated laser pulses at the interaction point can be determined as additional parameters for the data analysis. This selective multispectroscopy has recently been proven to be valid in studies using the combination of small-angle X-ray scattering (SAXS) with ion spectroscopy [18; 22]. In these studies, the characteristic and systematic structural ion spectra were specified by filtering the sample size and the intensity of XFEL pulses.  
In this work, we present results of enhanced multispectroscopic measurements with XFEL pulses. We recorded SAXS signals from Xe clusters in combination with ion time-of-flight (TOF) spectra and fluorescence spectra for every XFEL pulse. We observed clear diffraction patterns from Xe clusters and extracted both the XFEL fluence at the actual interaction point and the cluster size from them. We found that the XFEL fluence and the cluster size had a clear correlation with the fluorescence and ion TOF spectra. Our results on the fluence dependence of the maximum charge state and the mean charge state of Xe ions in the hard X-ray regime are in good agreement with preceding works in the soft X-ray and ultraviolet spectral regime [18; 22].