Self-amplified spontaneous emission free electron laser devices and nonideal electron beam transport

Leslie Lamberto Lazzarino ,D Di Giovenale,G Di Pirro,A Petralia,G Gatti,F Ciocci,F Villa,M Artioli,E Di Palma,L Giannessi,A Bacci,M Ferrario,A R Rossi ,E Chiadroni,M Bellaveglia,V Petrillo,M P Anania ,P Musumeci,G Dattoli,A Mostacci,A Cianchi,E Sabia,C Vaccarezza,R Pompili,Julietta V Rau

doi:10.1103/physrevstab.17.110706

Abstract

We have developed, at the SPARC test facility, a procedure for a real time self-amplified spontaneous emission free electron laser (FEL) device performance control. We describe an actual FEL, including electron and optical beam transport, through a set of analytical formulas, allowing a fast and reliable on-line ``simulation'' of the experiment. The system is designed in such a way that the characteristics of the transport elements and the laser intensity are measured and adjusted, via a real time computation, during the experimental run, to obtain an on-line feedback of the laser performances. The detail of the procedure and the relevant experimental results are discussed.

Highlights

At the SPARC test facility, a procedure for a real time self-amplified spontaneous emission free electron laser (FEL) device performance control
In a self-amplified spontaneous emission (SASE) free electron laser (FEL) the interaction of high quality electron beam with a long magnetic undulator provides the generation of bright EUV/x-ray pulses with suitable coherence properties for a different type of application [1,2,3,4]
The algorithm and the described procedure have been preliminarily checked on the SPARC FEL facility [19,20]

Summary

INTRODUCTION

In a self-amplified spontaneous emission (SASE) free electron laser (FEL) the interaction of high quality electron beam with a long magnetic undulator provides the generation of bright EUV/x-ray pulses with suitable coherence properties for a different type of application [1,2,3,4]. At the SPARC FEL [12] test facility a useful benchmarking tool has been developed to test the reliability of predictions given by different codes It could provide an important check of validation for models describing the nonlinear harmonic generation in SASE or seeded configuration [5,6,7,8,9]. Another important consideration emerging from this study is that semianalytical models are extremely reliable predicting tools, if properly used. The intensity growth along the undulator longitudinal coordinate z is described by means of a generalized logistic map [11] [hereafter referred as SASE logistic map (SLAP)], namely, 1098-4402=14=17(11)=110706(6)

AðzÞ þ

Energy E

PRELIMINARY EXPERIMENTAL RESULTS

Beam peak current

CONCLUSIONS