Charge-coupled Device Imaging Research Articles

Effective streamer discharge control by tailored nanosecond-pulsed high-voltage waveforms

In this paper we present our solid-state nanosecond pulse source (the solid-state impedance-matched Marx generator) which can generate arbitrary waveforms and which can be used for pulsed discharge generation. The purpose of the development of such a generator is twofold: by being able to change the waveform at will, we aim to control the discharge generated by such pulses very precisely which can be very useful for plasma applications, but also for more fundamental studies. In the presented study, we applied the arbitrary-waveform pulse source for streamer discharge generation in a cylinder-wire-like arrangement and used the arbitrary-waveform capability to change the rise time (in our experiments we used 6.8–26.2 ns) of unipolar positive pulses with 6-10 kV amplitude and 80 ns duration. Additionally, we introduced variations of a step in the rising edge of the waveform. We performed measurements both in air and nitrogen to electrically characterize the discharge while analyzing the streamer propagation in the plasma reactor with intensified charge-coupled device imaging and measured ozone generation (in air). The results show that we can indeed control the propagation of the streamer discharge with the stepped waveform, but that the rise-time variation has little effect on the streamer propagation in our system. However, the streamer velocity and structure differs significantly comparing discharges in nitrogen and air for the same applied voltage waveform. Additionally, for some of the stepped waveforms we found a slight increase of the ozone yield for air at low overall energy densities.

Ion fluxes and memory effects in an Ar–O2 modulated radiofrequency-driven atmospheric pressure plasma jet

In this work we used molecular beam mass spectrometry to characterize ion fluxes produced by a modulated radiofrequency (RF)-driven atmospheric pressure plasma jet operating in a homogeneous gas environment (Ar + 1% O2). The influence of the RF modulation frequency (100 Hz to 20 kHz) on the ion fluxes was investigated by time-resolved measurements, and the lifetimes of the dominant ions, O2 +, NO+, O−, O2 − and O3 −, were found to be 28 ± 2, 117 ± 8, 7.3 ± 0.4, 17 ± 1 and 23 ± 2 μs, respectively. The absolute ion densities in the near afterglow region were found to be of the order of 1011 cm−3. Significant differences in the dynamics of the positive and negative ions were found; these are explained by the presence of electrons at similar densities in the afterglow produced by electron detachment reactions from negative ions due to the large concentrations of atomic oxygen and singlet delta oxygen. Transitions in ion flux dynamics for different modulation frequencies and at the startup of the plasma were analyzed together with intensified charge coupled device images recording the plasma propagation in order to assess the dynamics of plasma plume propagation and how it is impacted by ‘memory effects’. Quantitative measurements of the ion densities enabling these memory effects are reported. The results in this paper highlight the tremendous impact of memory effects on plasma propagation and the corresponding pre-ionization.

Plasma-surface interaction: dynamic evolution of interfacial pattern modes during transformation process from dielectric to metallic substrate

Plasma–surface interaction is a complex system involving the codependency between the plasma and the substrate, especially for substrate’s with different permittivities. Therefore, a better understanding of the dynamic evolution of interactions with different substrates is essential for optimizing the required changes of specific substrates. In this work, we report two modes of interfacial pattern formation by a pulsed helium plasma jet interacting with indium tin oxide (ITO) glass and a metal substrate, and we mainly focus on the dynamic evolution process for interfacial pattern modes during a transformation process from ITO glass to metal substrate. Pattern morphology, current–voltage characteristics, intensified charge coupled device images, and reactive species distribution are used to examine the evolution mechanism of the plasma-jet–substrate interaction. Results show that, for the ITO glass substrate, a circular interfacial pattern with plenty of streamer channels is generated while, for the metal substrate, a constricted solid spot interfacial pattern is formed; these two pattern mode transformations are realized from the glass dielectric to the metal substrate. Furthermore, during the transformation process from the dielectric to metal substrate, the pattern area is gradually decreased, while the discharge intensity, emission intensity, and local electric field gradually become stronger. Importantly, by observing the dynamic behavior of the interfacial pattern, the ionization wave on the substrate surface is stopped from spreading toward the metal direction and a bright touch point appears at the interface between the dielectric and the metal, while the surface ionization wave still spreads and has no influence on the other direction besides the metal direction. Additionally, the evolution mechanism of pattern mode transformation is discussed, which may be attributed to the difference in the substrate conductivity leading to the different distribution of the local electric field. This study is beneficial to deep insights into the nature of the plasma–surface interaction.

Caudal autotomy and regeneration of arc in a 3D gliding arc discharge plasma

To gain a better understanding of the mechanism governing arc dynamics in 3D gliding arc discharge (GAD) plasma, the spatio-temporal evolution of GAD was investigated in a reverse vortex flow by a novel reactor with ring (powered electrode, PE) and truncated cone (ground electrode, GE) electrodes. A newly underlying mechanism governing arc evolution in 3D GAD was gained with combination of flow field simulation, synchronous electrical characteristics, intensified charge coupled device images and high-speed photos. The spatio-temporal analysis indicates that, being different from the well-known ignition–gliding–extinction mechanism occurring in traditional GAD, the PE arc root glides continuously in the 3D GAD, but the GE arc root features jumps from the end of the gliding path to the beginning of the next one. By means of the jumping, the arc auto-sheds the caudal part of the arc and a new arc tail is simultaneously generated, rather than rebuilding a new arc channel back to the shortest electrode gap. With this special behavior of caudal autotomy and regeneration, the main part of the arc remains for each jump. This new insight improves the understanding of the discharge mechanism governing arc evolution in 3D GAD and provides a reference for optimization design of gliding arc plasma in a vortex flow.

Combined microwave and laser Rayleigh scattering diagnostics for pin-to-pin nanosecond discharges

In this work, the temporal decay of electrons produced by an atmospheric pin-to-pin nanosecond discharge operating in the spark regime was measured via a combination of microwave Rayleigh scattering (MRS) and laser Rayleigh scattering (LRS). Due to the initial energy deposition of the nanosecond pulse, a variation in the local gas density occurs on the timescale of electron decay. Thus, the assumption of a constant collisional frequency is no longer applicable when electron number data are extracted from MRS measurements. To recalibrate MRS measurements throughout the electron decay period, temporally resolved LRS measurements of the local gas density were performed over the event duration. The local gas density was calculated to be 30% of the ambient level during the later stages of electron decay, and it recovers at about 1 ms after discharge. A shock front traveling approximately 500 m/s was additionally observed. Coupled with plasma volume calibration via temporally resolved intensified charge-coupled device imaging, the corrected decay curves of the electron number and electron number density are presented with a measured peak electron number density of 4.5 × 1015 cm−3 and a decay rate of ∼(0.1–0.35) × 107 s−1. A hybrid MRS and LRS diagnostic technique can be applied for a broad spectrum of atmospheric-pressure microplasmas where a variation in the gas number density is expected due to energy deposition in the discharge.

Systematic investigation of the pulsed barrier discharges in flowing and stationary gas: From differences to similarities

Pulsed dielectric barrier discharges in flowing and stationary helium at atmospheric pressure are comparatively studied. The discharges are generated in plane-parallel configuration and driven by positive voltage pulses. The intensified charge coupled device imaging and electrical measurements are used for temporally, spatially, and spectrally resolved discharge emission. The populations of excited states are investigated by optical emission and absorption spectroscopy. The discharge operating in flowing helium is characterized by a single current pulse per each voltage flank and a “residual current peak.” In stationary helium or in flowing helium with low velocity (<10 cm/s), multiple current pulses are observed. The appearance of the subsequent current pulse(s) is related to the disappearance of the “residual current peak.” Besides these differences between the two discharge regimes, some similarities are also registered. The maximum emission intensity is reached at the cathode, even for the subsequent current pulses formed in stationary helium, confirming the generation of the glow and multi-glow discharges. Also, the most important similarities between the discharges working in stationary helium and in flowing gas mixture, in relation to flowing helium mode, are discussed. Finally, the subsequent current pulses formed in multi-glow discharges are due to re-ignition of the discharge dominantly by direct electronic excitation and ionization processes, not by Penning ionization, because of the decrease in metastable atoms density and their lifetime. In addition, the metastable lifetime reaches a critical value, for which the discharge transits from glow to multi-glow mode, when the gas velocity or its composition changes.

Estimation of suspended matter concentration in manwan reservoir, lancang river using remotely sensed small satellite constellation for environment and disaster monitoring and forecasting (HJ-1A/1B), charge coupled device (CCD) data

ABSTRACT The estimation of total suspended matter (TSM) concentration is crucial in monitoring, evaluating, and protecting water quality. Many empirical and semi-analytical models have been established for clear or extremely turbid water bodies; however, only a few are applicable to inland, extremely turbulent deep rivers. Using in situ data from the water of the Manwan reservoir, we developed a robust algorithm to estimate the TSM concentration in the Manwan reservoir, with a root mean square error (RMSE) ≤ 4.43 mg L−1 and a mean absolute percentage error (MAPE) of 23.2%, indicating the feasibility of the empirical model for estimating TSM. The empirical model was then applied to 251 Small Satellite Constellation for Environment and Disaster Monitoring and Forecasting loaded with the Charge Coupled Device (HJ-CCD) images to derive TSM distribution maps from 2009 to 2018. The estimated TSM concentrations exhibited significant spatial and seasonal changes, revealing relationships among TSM, wind speed, and precipitation. The spatial heterogeneity was significantly higher downstream than upstream in the reservoir due to watershed inputs and anthropogenic dredging activity. The temporal heterogeneity of TSM, significantly higher in summer and autumn than in winter and spring, was mainly caused by seasonal rainfall. Our study shows that the empirical model for HJ-CCD images can be used to quantitatively monitor the TSM in inland rivers.

Astronomical Analysis on Star Exploration: A Quantitative Research on Luyten’s star based on Proper Motion and Photometric Brightness.

There are many intrinsic properties for the stars and some of them can be investigated by an astronomical way. Through an investigation on one Luyten’s star (LHS33), this paper presents one basic astronomical analysis method and result about its high proper motion, and brightness for four different filters (RC, V, Blue, Ic). It is an essential element when exploring the target star and obtaining its properties. The method used in this study is a measurement of astrometric position and photometry. All of the measurements require the original CCD (Charge-coupled Device) images obtained from the telescope and a series of software processing. The results obtained mainly are about the value of proper motion, apparent magnitude in these 4 filters above. For instance, the proper motion calculated for right ascension (RA) is 0.59 ± 0.10 arcsecs per year and for declination (Dec) is -3.70 ± 0.11 arcsecs per year. The valued calculations suggest an agreement with current published data. It verifies the correction for both operation procedure and data analysis. It gives a specific interpretation on why such the observation happened based on the quantitative analysis.

The influence of target surface position on plasma characteristics in dual-pulse fiber-optic laser-induced breakdown spectroscopy

Laser-produced plasmas of dual-pulse fiber-optic laser-induced breakdown spectroscopy with different target positions relative to the waist region of laser focusing are studied using fast imaging and optical emission spectroscopy (OES). The laser energy of the two laser pulses is both maintained at around 18 mJ (i.e. the total energy is 36 mJ). The inter-pulse delay is kept at 250 ns. Ten spot sizes changing from 947 to 543 μm are obtained by precisely adjusting the distance between the focusing lens and the target surface. The profile of laser beam output from fiber shows a distinct top-hat shape. When approaching the dual-pulse waist region, the self-absorption and self-reversal of matrix iron lines gradually become intense while the plasma emission is enhanced, but the signal-to-noise ratio of minor elements gradually decreases. Under a similar spot size, the emission intensity with the target surface behind the waist region is weaker than that in front of the waist region and also with greater jitters. The target surface position is optimized to deviate from the waist region by ~ 1.3–1.6 mm towards the focusing lens for improving SNR of minor elements, corresponding to the lens-to-sample distances of 11.8–12.1 mm. Plasma morphology has undergone a transformation from stream- to umbrella-like structure using the recorded Intensified Charge-Coupled Device (ICCD) images. The expansion distance of the plasma front is increased from 1.07 to 1.28 mm, and the plasma volume is increased from 0.59 to 1.60 mm3. Besides, by utilization of OES, the maximum variation of plasma temperature and line broadening width rise to 2702 K from 1630 and to 0.0492 from 0.0316 nm along the vertical direction. The significant increase of optical thickness and nonuniformity of plasma temperature and density is the main reason for the intensification of self-absorption.

Tyramide signal amplification and enzyme biocatalytic precipitation on closed bipolar electrode: Toward highly sensitive electrochemiluminescence immunoassay

Abstract A novel closed bipolar electrode-based electrochemiluminescence (BPE-ECL) imaging platform for visual detection of cardiac troponin I (cTnI) was constructed using tyramine signal amplification (TSA) strategy and enzyme-catalyzed precipitation techniques (BCP). In this platform, tyramine-HRP repeats formation and the BCP were executed on the cathodic pole in the presence of H2O2, which the ECL from Ru(bpy)32+/TPA system was used as signal reporter on the anodic pole. In the presence of cTnI, a large number of HRP from HRP-Au NPs-Ab compounds and tyramine-HRP repeats catalyze the formation of insoluble precipitation on the cathodic pole of the BPE, resulting in the decreased ECL from Ru(bpy)32+/TPA system on the anodic pole. Thanks to the TSA and BCP on the cathodic pole of the BPE platform, the method for cTnI detection exhibits the detection limits of 5.0 × 10−13 g/mL by a photomultiplier tube and 5.0 × 10-12 g/mL by a charge-coupled device imaging. Furthermore, the content of cTnI in human serum samples was determined and the recovery was between 90.0 % and 112.0 %. This multiple signal amplification strategy provides new perspectives for the BPE-ECL imaging platform in the biochemical analysis of biomarkers with low abundance.

Analysis and Comparison of Three Classical Color Image Interpolation Algorithms

With the development of society, the progress of science and technology, the level of computer has been improved. Digital imaging technology has also achieved unprecedented development. The most commonly used digital cameras are Charge-coupled device (CCD) and Complementary Metal Oxide Semiconductor (CMOS) image sensors. Bayer filters are often used to help sensors capture color information. However, only one component can be achieved per pixel. Full-color images must be obtained by color interpolation. Therefore, the color interpolation algorithm has attracted the attention of the academic community. In this paper, three classical color interpolation algorithms- Bilinear interpolation algorithm, COK Algorithm, Gradient Interpolation Algorithm- are compared and studied. The Optimal Algorithm is selected by comparing false color, noise and color moire fringe. After comparison, it is found that the three basic algorithms will have color moire fringes appear. But the gradient interpolation algorithm has the least moire fringe and noise. COK Algorithm, second of all. But the COK Algorithm has color overflows.

A Compact Calibratable Pulse Oximeter Based on Color Filters: Towards a Quantitative Analysis of Measurement Uncertainty

Compact and low-cost opto-biomedical sensing systems today are ubiquitously available for measuring the oxygen saturation in blood. The oxygen saturation is derived by a complex, usually not well defined analytical process from the optical absorption of tissue at different wavelengths. The amount of information, which is originally contained in absorption measurements, is drastically reduced by this circumstance. However, the reliability of the analytical process as well as the influence of external parameters like blood pressures on the experimental uncertainty of such systems are widely unknown. Thus, to explore the experimental uncertainty quantitatively, original experimental data have to be used. In commercial systems, however, these data are usually not accessible. Therefore, test systems with full access to original absorption data are necessary. In this work, we develop and describe a test system consisting of color filters and a charge-coupled device (CCD) image sensor, which has substantial advantages in comparison to usually used systems based on multi-color light-emitting diodes (LEDs). Color filters with well-defined filter functions allow for a higher spectral resolution, and will finally guide the way to multi-spectral analysis of blood absorption measurements with reduced uncertainty.

Development of on-chip pattern processing in event-driven SOI pixel detector for X-ray astronomy with background rejection purpose

This paper reports on the development of on-chip pattern processing in the event-driven silicon-on-insulator pixel detector for X-ray astronomy with background rejection purpose. X-ray charge-coupled device (CCD) detectors, well-established pixel detectors used in this field, has proven that classification of detected events considering their spatial pattern is effective for particle background rejection. Based on the current architecture of our device and from the CCD images obtained in space, we first established a design concept and algorithm of the pattern processor to be implemented. Then, we developed a new device, including a prototype pattern-processing circuit. Experiments using X-ray and beta-ray radioisotopes demonstrated that the pattern processor properly works as expected, and the particle background rejection is realized in an on-chip fashion. This function is useful, especially in a limited-resource system such as the CubeSat.

Optical Design of Compact Space Autonomous Docking Instrument with CMOS Image Sensor and All Radiation Resistant Lens Elements

Built-in autonomous stereo vision devices play a critical role in the autonomous docking instruments of space vehicles. Traditional stereo cameras for space autonomous docking use charge-coupled device (CCD) image sensors, and it is difficult for the overall size to be reduced due to the size of the CCD. In addition, only the few outermost elements of the camera lens use radiation-resistant optical glass material. In this paper, a complementary metal–oxide semiconductor (CMOS) device is used as the image sensor, and radiation-resistant optical glass material is introduced to all lens elements in order to make a compact and highly reliable space grade instrument. Despite the limited available material, a fixed focus module with 7 lens elements and overall length of 42 mm has been achieved, while meeting all the required performance demands for the final vision-guided docking process.

Helicon-Wave-Excited Helium Plasma Performance and Wall-Conditioning Study on EAST

Helium helicon wave plasma (He-HWP) wall conditioning was performed with a specially designed antenna system on the Experimental Advanced Superconducting Tokamak (EAST) under strong magnetic field (0.5–1 T). The maximum effective RF power $P_{\mathrm {eff}}$ was 30 kW at 27 MHz, and the He pressure was fixed at ~0.27 Pa. Charge-coupled device (CCD) images indicated that toroidal homogeneous but poloidal inhomogeneous He-HWPs were obtained. An obvious desorption of H2 and HD was found during He-HWP operation. Deuterium was desorbed mainly in the form of HD, with a removal rate of ~1021–1022D atoms/h. Additionally, the residual gas analyzer (RGA) results also showed a steep rise in H/D desorption during mode transition (inductively coupled plasma (ICP) $\to $ HWP) with increased $P_{\mathrm {eff}}$ from 5 to 15 kW, then a slight decline in the HWP mode with relatively higher $P_{\mathrm {eff}}$ (>15 kW), which was further verified by the spectral data of hydrogen Balmer series ( $\text{H}_{\alpha }$ and $\text{D}_{\alpha }$ ).

Long-term remote tracking the dynamics of surface water turbidity using a density peaks-based classification: A case study in the Three Gorges Reservoir, China

• A water optical classification method was developed using density peaks. • The class-specific retrieval models of surface water turbidity were established. • Long-term dynamics of surface water turbidity was tracked using satellite images. • Interaction of water level and rainfall is probably the main environmental driver. Surface water turbidity (SWT), as a low-cost proxy of surface suspended sediment, is important for characterizing the hydro-ecological process and light availability in the lake or reservoir ecosystem. In this study, we proposed the combined use of HJ-1 charge-coupled device imaging and field observation to track the long-term SWT dynamics with environmental changes in Lakes Gaoyang, Hanfeng, and Changshou of the Three Gorges Reservoir, China. In situ remote sensing reflectance spectra were utilized to develop the characteristic spectral indexes for the SWT estimation in different water optical classes separated by a density peaks-based classification. Significant correlations were found between the red-, four-band, band ratio spectral indexes and SWT (determination coefficient >0.71 and root-mean-square error <8.32 nephelometric turbidity unit), suggesting a crucial role of the class-specific retrieval models for the SWT estimation in optically complex waters. The proposed method was further used to monitor the spatio-temporal SWT dynamics over the three lakes from 2008 to 2019, demonstrating that the significant SWT decline in Lakes Gaoyang and Hanfeng and the relatively stable trend in Lake Changshou during the 11-year period. Specifically, the SWT decreasing trends may be attributed to the water level linkage mechanism of Three Gorges and Wuyang Dams. In addition, analyses with simultaneous environmental factors showed that the seasonal and inter-annual variations of SWT appear to be closely correlated with water level and rainfall. Long-term remote tracking of the SWT dynamics presented in this study could provide new insight and reference for reservoir management in the post-Three Gorges Project Era.

Research progress on solidification structure of alloys by synchrotron X-ray radiography: A review

Abstract The synchrotron radiation technology has recently emerged as a powerful tool to characterize the real-time microstructure evolution during solidification of alloys. Compared with other methods, the synchrotron radiation technology, along with its unique advantages of strong brightness, high energy, excellent resolution, and good monochromaticity, allows for capturing the dendrite evolution behavior of alloys in real time and can be dynamically coordinated with high-resolution CCD (Charge-coupled Device) imaging systems. This paper briefly reviews the recent advances in developing synchrotron radiation for solidification of alloys with low, medium, and high melting points, and under the external electric, magnetic, and ultrasonic fields. Furthermore, a series of microstructural features and behaviors such as dendrite morphology, growth orientation, dendrite fracture, and rotation are described in detail. Finally, the development trends and application prospects of synchrotron radiation technology in alloy solidification are forecasted.

Gas Absorption and Mass Transfer in a Pore-Array Intensified Tube-in-Tube Microchannel

A pore-array intensified tube-in-tube microchannel (PA-TMC), which is characterized by high throughput and low pressure drop, was developed as a gas–liquid contactor. The sulfite oxidation method was used to determine the oxygen efficiency (φ) and volumetric mass transfer coefficient (kLa) of PA-TMC, and the mass transfer amount per unit energy (e) was calculated by using the pressure drop. The effects of structural and operating parameters were investigated systematically, and the two-phase flow behavior was monitored by using a charge-coupled device imaging system. The results indicated that the gas absorption efficiency and mass transfer performance of the PA-TMC were improved with increasing pore number, flow rate, and number of helical coil turns and decreasing pore size, row number, annular size, annular length, and surface tension. The φ, e and kLa of PA-TMC could reach 31.3%, 1.73 × 10−4 mol/J, and 7.0 s−1, respectively. The Sherwood number was correlated with the investigated parameters to guide the design of PA-TMC in gas absorption and mass transfer processes.

Fine Fabrication and Optical Waveguide Characteristics of Hexagonal tris(8-hydroxyquinoline)aluminum(Ⅲ) (Alq3) Crystal

Herein, we reported on the precise growth and optical waveguide characteristics of hexagonal tris(8-hydroxyquinoline)aluminum(Ⅲ) (Alq3) micro-crystals (MCs). The hexagonal Alq3 MCs were prepared using surfactant-assisted assembly growth with the help of cetyltrimethylammoniumbromide (CTAB), in which the crystallization occurred as a result of molecular assembly and packing. Also, we adjusted the molar ratio of Alq3 and CTAB for the control degree of crystallization. The formation and structure of Alq3 MCs were investigated using field-emission scanning electron microscopy and X-ray diffraction pattern experiments, respectively. The solid-state laser confocal microscope-photoluminescence spectra and charge-coupled device images for the Alq3 MCs were measured to study the luminescence efficiency and colors, respectively. The optical waveguide performance of the hexagonal Alq3 MCs was measured for each side direction. According to our results, crystalline Alq3 micro-crystals are promising materials for application to the development of optical communication devices.

Single grain infrared photoluminescence (IRPL) measurements of feldspars for dating

Existing infrared photoluminescence (IRPL) systems have used pulsed infrared stimulation (~830 nm) and measured IRPL emission (at 880 or 955 nm) using time resolved data collection with photomultipliers. Breakthrough of the infrared stimulation light overwhelms the IRPL, but the delayed emission during the laser-off period has been used instead.This paper describes a system for measurement of the IRPL signal from single sand-sized grains of feldspar. The attachment uses an electron-multiplying charge-coupled device (EMCCD) imaging system, and has two innovations that make it possible to use such a detector to obtain IRPL data. First, the optical detection system has been designed to minimise stray light and maximise the efficiency with which filters reject the stimulation light. This acts to reduce, but not eliminate, the breakthrough. Second, by placing the sample to be measured in a clearly defined sample grid, the spatial resolution provided by the EMCCD has been used to differentiate between regions of the image where IRPL is emitted and adjacent regions where only breakthrough is expected. This allows quantification of the breakthrough and effective subtraction to isolate the IRPL signal from the grains of interest.The attachment has been used to measure IRPL from single sand-sized grains of feldspar from an aeolian dune from New Zealand. A 1W UV LED (365 nm) is also added to the system and this is effective at resetting the IRPL signal, permitting a single aliquot regenerative dose (SAR) protocol to be used to measure equivalent dose (De). Measurement of a known laboratory dose (104 Gy) demonstrates the reproducibility of the attachment, with no overdispersion observed in the resulting single grain De values. The recovered dose is within 10% of the given dose. The natural IRPL signal yields De values from single grains with low overdispersion (22%) and giving a weighted mean value (103 ± 5.8 Gy) that is consistent with that obtained using post-IR IRSL measurements (105 ± 3.8 Gy). The attachment described here provides IRPL measurements on single grains suitable for exploring the potential of this novel and exciting signal for dating geological sediments.