Abstract
Recently, measurements of few-picosecond (ps, 10−12 s) pulses of laser-driven protons were realised by the observation of transient opacity in SiO2. This ultrafast response could be understood by the formation of self-trapped excitonic states in the material, creating a rapid de-excitation channel for conduction band electrons. Here we extend this work to examine the onset and evolution of an ion-induced opacity in transparent dielectrics, namely multicomponent variants of SiO2. The fast recovery observed in SiO2 is in sharp contrast to borosilicate (BK7) and soda-lime glasses. We find that the opacity decay timescales for BK7 and soda-lime glass are orders of magnitude greater than the 3.5 ps proton pump pulse duration and discuss the underlying processes which may be affecting the extended recovery of the material. Simultaneous probing with 2nd harmonic radiation allows estimates of ultrafast electron dynamics due to proton interactions in matter to be investigated, this indicates that a rapid evolution of an initially unstructured ion-induced dose distribution seeds the longer term recovery pathways in the irradiated dielectrics. When combined, these results demonstrate the efficacy of utilising ultrafast laser-driven ionising radiation along with highly synchronised probe pulses to enable the study of ion-induced damage in matter on ultrafast timescales in real time.
Highlights
Understanding the effects of ionising radiation in matter has been a focus of research for decades; from investigating the response of cells when undergoing hadron therapy in medicine [1], changing the optical properties of a material [2, 3], or the damage induced in materials deployed in radiation harsh environments such as space—where cosmic rays and other forms of ionising radiation can pose a threat to sensitive electronic equipment [4,5,6]
We find that the opacity decay timescales for BK7 and soda-lime glass are orders of magnitude greater than the 3.5 ps proton pump pulse duration and discuss the underlying processes which may be affecting the extended recovery of the material
Simultaneous probing with 2nd harmonic radiation allows estimates of ultrafast electron dynamics due to proton interactions in matter to be investigated, this indicates that a rapid evolution of an initially unstructured ion-induced dose distribution seeds the longer term recovery pathways in the irradiated dielectrics
Summary
Understanding the effects of ionising radiation in matter has been a focus of research for decades; from investigating the response of cells when undergoing hadron therapy in medicine [1], changing the optical properties of a material [2, 3], or the damage induced in materials deployed in radiation harsh environments such as space—where cosmic rays and other forms of ionising radiation can pose a threat to sensitive electronic equipment [4,5,6] Many of these studies focus on the longer term effects such as cell death or the effect on structural integrity and permanent damage centre formation in the material [7,8,9,10]. Understanding how the associated early stage dynamics underpin the formation of these final states is very challenging, both experimentally and computationally This is because the nascent phase can evolve over time frames that span from femtoseconds (fs, 10−15 s) to nanoseconds (ns, 10−9 s) [11]. The use of traditional radio-frequency (RF) particle accelerators provide stable high energy pulses, this is at the cost of long pulse durations (>100 ps) with significant levels of timing jitter with respect to optical probe pulses, due to the ion and probe sources being coupled electronically [18]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
