## 4 Data Acquisition System for High Repetition Rate Performance  
Routine operation of PW-class laser-plasma experiments at high repetition rates would represent a new paradigm in terms of statistically relevant discoveries of new plasma acceleration regimes, investigation of complex effects, along with mitigation of laser-plasma instabilities to improve the stability of secondary sources (particles and radiation). This new scenario will require not only fast target delivery devices, but also fast diagnostics and data acquisition systems, along with real-time analysis tools allowing online characterization of laser-plasma generated secondary source parameters. Online diagnostic systems for laser-generated ion beams at the TERESA and ELIMAIA beamlines are described in detail in [13; 17; 18], therefore, the following will mainly focus on recently developed and tested data acquisition systems and data analysis tools for high repetition rate operation (up to 10 Hz). Nevertheless, in terms of laser-plasma ion diagnostics, it is worth mentioning that one of the main challenges in the detection of laser-accelerated ions is the high-peak flux (\(10^{10}\)-\(10^{12}\) ions/pulse) and the short bunch duration (0.1-1 ns), hence the very high dose-rates in a single pulse (around \(10^{9}\) Gy/s). Thus, innovative techniques and devices for beam characterization have been developed for the ELIMAIA beamline, since robust online diagnostics represents one of the crucial steps towards multidisciplinary applications of such non-conventional beams [18]. The main online ion diagnostic system is based on the time-of-flight (TOF) technique using diamond and silicon carbide detectors, as reported in the literature [12; 13; 27], which offers the possibility to monitor shot-by-shot the main ion beam features up to a repetition rate of 10 Hz. Another key ion diagnostic system is the widely used Thomson Parabola Spectrometer (TPS), which allows the detection of energy-resolved ion spectra while discriminating ions with different charge-to-mass ratios by means of combined use of electric and magnetic fields [28; 29]. In high repetition rate TPS configuration, deflected ions are typically observed and amplified by means of a microchannel plate (MCP), and are sent to a phosphor screen, thus producing an image of the energy-resolved ion spectra subsequently recorded by a CCD camera. The acquisition of the raw CCD image is controlled by a trigger signal from the laser. The use of a repetition rate of 1-10 Hz requires a data acquisition system (DAS) with the ability to measure and store a large amount of data. For this purpose, we have developed a data acquisition system based on commercially available oscilloscopes (Agilent Technologies, Santa Clara, CA, USA, DSO9064A; LECROY, Chestnut Ridge, NY, USA, WAVERUNNER 8404M and WAVERUNNER 8254), but with the capability of real-timedata transfer to the computer using standard TCP-IP communication over a local area network (LAN). The DAS system was tested using all three oscilloscopes (with four active channels per device) operated simultaneously in one LAN. After successful triggering, data are acquired into the oscilloscope's memory. The dedicated NI Labview routine that follows the trigger status initiates the transfer of acquired data to the PC. During a test, the code allowed to count the data loss within a series of 200 subsequent triggers at different laser repetition frequencies, 1, 3.3, and 10 Hz (i.e., 1 s, 0.3 s, and 0.1 s), and various sampling rates per channel. Figure 5 depicts the data acquisition time for two extreme configurations: (a) delay between triggers of 1 s/1000 samples per channel; and (b) delay between triggers of 0.1 s/25,000 samples per channel. In the first case, a successful read of data happens in between two triggers without affecting the next measurement, while for the second configuration (where data loss is 29%), after few long data reads (longer than 10 Hz limit, as depicted by the orange line) a subsequent loss of data occurs.