Optimizing pyroelectric x-ray detectors for synchrotron applications S. R. Kane, R. W. Whatmore, P. K. Jha, P. K. Mehta Aip Advances, 2025 This study presents a comprehensive investigation of pyroelectric detectors for high-energy x-ray detection. We compare three high-performance pyroelectric materials (LiTaO3, LiNbO3, and triglycine sulfate) in two geometries, thermally coupled and uncoupled, and contrasting current with conventional voltage amplifier designs. The results obtained using 17 keV synchrotron radiation demonstrate that current amplification significantly outperforms voltage follower configurations, achieving responsivity values of up to 105 V/W with substantially improved signal-to-noise ratios. Of the three materials tested, triglycine sulfate exhibits superior sensitivity when used in thicker formats (specific detectivity D* ∼ 7.60 × 107 cm Hz1/2 W−1), although LiTaO3 offers better thermal stability for practical applications. Further optimization through thickness reduction of LiTaO3 crystals in the range of 500–100 μm yielded substantial improvements in D*, with the thinnest crystals achieving D* values of ∼1.1 × 108 cm Hz1/2 W−1 in uncoupled geometry, which maximizes thermal isolation and temperature rise per unit-absorbed power. These results validate our theoretical models, which predict performance enhancements through optimal thermal management and amplification strategies. This establishes new benchmarks for pyroelectric-based x-ray detection.
Green Protocol For Synthesis of Cu2O@g-C3N4 Photocatalysts For 1, 4 Radical Oxidative Addition of Trans Crotonaldehyde Under Visible Light Condition Bharat A. Maru, Vandana J. Rao, Sanjeev Kane, U. K. Goutam, Chetan K. Modi Chemphotochem, 2024 Using visible light conditions, we have developed a green protocol to prepare copper oxide‐doped graphitic carbon nitride (Cu2O@g‐C3N4) photocatalysts with varied ratios of g‐C3N4 nanosheets to copper oxide‐dopant (0.1 %, 0.5 %, 0.7 %, and 5 % respectively) and characterized through various physicochemical techniques. These photo‐responsive catalysts were used for the 1,4 radical oxidative addition of trans crotonaldehyde into β‐hydroxybutyric acid (BA) as a major product, utilizing 30 % hydrogen peroxide as an oxidant and a white LED (Light Emitting Diode) source. Under the innoculous eco‐friendly stipulations, Cu2O@g‐C3N4 (5 %) exclusively promoted the aforementioned reaction leading to 99.85 % trans crotonaldehyde conversion with 66.57 %, 24.1 %, and 9.1 % selectivity for β‐hydroxybutyric acid, crotonic acid and subsequent radical synthesis, respectively.
Development of piezo-actuated x-ray deformable mirror for vertical focusing of synchrotron radiation at Indus-2 Sumit, Hari Shankar Kumar Jha, A.K. Biswas, M.K. Swami, A. Sagdeo, C. Mukherjee, S.R. Kane, A.K. Sinha, Tapas Ganguli, S.K. Rai, Rahul Shukla Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment, 2024 Piezo-actuated x-ray deformable mirrors (PXDMs) can effectively control the surface profile with sub-nanometre accuracy for adaptive focusing and correct the wavefront distortion generated due to imperfections in optical components or other extraneous effects like heat load, minor misalignments of synchrotron radiation beamline . Generating and controlling the desired shape of PXDMs with sub-nanometre accuracy is very challenging due to the presence of a large number of actuators and constraints related to nonlinearity of piezoactuator , boundary conditions, fabrication related limitations and the requirement for ex-situ as well as in-situ characterization of PXDM. To accomplish this, a PXDM of zerodur with multiple electrodes on a piezoactuator has been developed for vertical focusing of synchrotron x-rays for the first time in India. The PXDM has been fabricated and characterized by in-house developed technologies. The iterative piezo response function-based optimization technique is used to optimize the electric fields of individual piezoactuators in order to achieve the desired parabolic shape of the PXDM. The ex-situ characterization showed that the PXDM can achieve the target parabolic profile with 42 nm root-mean-square error. Furthermore, in-situ characterization at a beamline, BL-12, of Indus-2 synchrotron radiation source using PXDM has confirmed the focusing of collimated x-ray beam in the vertical direction from FWHM 235 μm to FWHM 83 μm.
A versatile beamline for soft x-ray reflectivity, absorption, and fluorescence measurements at Indus-2 synchrotron source Mohammed H. Modi, Rajkumar Gupta, Shruti Gupta, Praveen Kumar Yadav, Chander Kant, Sohan Lal, V. K. Raghuvanshi, S. R. Kane Review of Scientific Instruments, 2024 A versatile beamline for performing reflectivity, fluorescence, and absorption experiments in the soft x-ray region of 100–1500 eV is commissioned on a bending magnet port of the Indus-2 synchrotron source. A high vacuum 2-axis reflectometer with x, y, and z sample scanning stages is installed. This reflectometer is used to measure the reflectivity of large samples up to 300 mm in length and 5 kg in weight. This feature is useful for characterizing x-ray optical elements, such as mirrors, gratings, and multilayers. A flange mounted silicon drift detector is installed in the downstream of the reflectometer for soft x-ray fluorescence measurements. The soft x-ray absorption measurements are carried out in the total electron yield and partial fluorescence yield modes. Integration of three different experimental techniques in the experimental station makes the beamline versatile for materials science applications as it provides structural, chemical, and electronic state information by performing the required experiments in an identical environment. The beamline uses a varied line spacing plane grating monochromator and gives a high flux (∼109 to 1011 photon/s) with a moderate resolution (λ/Δλ ~1000–5000). A three-mirror-based higher harmonic setup is incorporated to get rid of harmonics and to get a high spectral purity monochromatic beam with less than 0.1% harmonic content. In the present article, the beamline optical scheme, mechanical configuration, and details of the experimental setups are presented, along with a few representative results of each experimental mode.
Thermal Wave Detection Technique for High-Resolution XANES Spectroscopy of Lead and Platinum Metal Foils Sanjiv Kane, Manvendra Singh, Srinibas Satapathy, Prashant Mehta, Prafulla Jha, Rajashri Urkude IEEE Ultrasonics Ferroelectrics and Frequency Control Joint Symposium Uffc Js 2024 Proceedings, 2024 X-ray Absorption Near Edge Structure (XANES) spectroscopy is a powerful tool for investigating the electronic and structural properties of materials. Due to the availability of an intense tuneable X-ray source in the form of synchrotron radiation, X-ray spectroscopy has flourished in the past ten years. A large number of detection techniques have been developed to measure the absorption of X-rays by thin films, metal oxide films and surface layers. All the detection techniques measure a signal that is related to the probability of exciting a core electron. In this study, we introduce a novel application of the thermal wave detection method using a pyroelectric detector (LiTaO3) for acquiring XANES spectra of Lead (Pb) and Platinum (Pt) metal foils. By exposing these metal foils to synchrotron X-ray radiation, the absorbed X-rays generate localized heating, leading to thermal waves. These thermal waves are detected and analyzed using the pyroelectric detector to obtain the XANES spectra.
