Acute Esophageal Necrosis as an Unusual Cause of Epigastric Pain in the Emergency Department

Epigastric pain is a common complaint in the emergency department (ED). Clinicians require skills to differentiate the epigastric pain in the ED. Here, we report a case of acute esophageal necrosis (AEN) as a cause of epigastric pain in the ED. An 83-year-old woman with diabetes mellitus visited the ED because of worsening subacute epigastric pain, nausea, and anorexia. The patient’s vital signs and general condition did not seem serious at first in the ED. Esophagogastroduodenoscopy revealed circumferential inflammation and necrosis of the esophageal mucosa. The patient was diagnosed with AEN and admitted. The patient’s condition suddenly worsened on the sixth day. Citrobacter koseri was detected in blood culture, and although the patient was treated with antibiotics, she died on the twelfth day. In our case, epigastric pain, a common complaint in the ED in elderly women, was caused by AEN, an uncommon disease. The patient was seemingly stable at first but rapidly developed sepsis and died. In this case, we identified two important clinical issues: (1) AEN is an uncommon cause of epigastric pain in the ED, but it is worth considering. (2) Once AEN is diagnosed, the clinician should engage in further investigations such as esophageal and blood culture tests and close follow-up of the clinical course, even if patients’ condition does not appear to be serious

Development of carbon thin film for Laser‐driven heavy ion acceleration using a XeCl excimer laser

The carbon thin film as a target for laser‐driven heavy ion acceleration has been developed using the carbonization of polyimide induced by the irradiation of a XeCl excimer laser. The relationship between the depth of the crater produced by the laser irradiation and the laser fluence were measured in order to clear the carbonization mechanisms of polyimide. The melting threshold of polyimide was estimated to 0.058 J/cm2. It is found that the carbonization is induced by the irradiation with the laser fluence around or under the threshold

Denoising application for electron spectrometer in laser-driven ion acceleration using a Simulation-supervised Learning based CDAE

Real experimental measurements in high-radiation environments often suffer from a high-flux of background noise which can limit the retrieval of the underlying signal. It is important to have an effective method to properly remove unwanted noise from measurement images. Machine learning methods using a multilayer neural network (deep learning) have been shown to be effective for extracting features from images. However, the efficacy of such methods is often restricted by a lack of high-quality training data. Here, we demonstrate the application for noise removal by performing simulations to generate virtual training data for a denoising deep-learning model. We first apply the model to simulations of an electron spectrometer measuring the energy spectra of electron beams accelerated from the interaction of an intense laser with a thin foil. By considering the chi-squared test and image test-indexes, namely the peak signal-to-noise ratio (PSNR) and structural similarity index measure (SSIM), we found our method to be highly effective. We then used the trained model to denoise real experimental measurements of the electron beam spectra from experiments performed at a state-of-the-art high-power laser facility. This application is offered as a new method for effectively removing noise from experimental data in high-flux radiation background environment

Denoising technique of an in-line electron energy spectrometer based on the feature filtering

On the experiment for laser-driven ion acceleration at J-KAREN-P[1] with pulse repetition rates of 0.1 Hz, the angular distribution of electron spectrum is diagnosed by multiple electron spectrometers. The electron spectrometer with comprising a bending magnet, a CCD camera and a scintillator is placed in the main vacuum chamber. When the laser focus on the target, many radiations generated in the main vacuum chamber, therefore, CCD camera is exposed to the radiation and distorted the measured images. We need to develop a new technique for removing noise (denoising) from a noisy image and recovering a true measurement image. In recent years, with the development of machine learning methods such as Deep-Learning, "Deep-Learning based Feature filtering" that uses a feature value of an image obtained from machine learning as a base and reproduces a true image from a noisy image is developed[2]. This filtering technique is a new technique of reconstructing a denoising image by separating noise and true data with the feature value of the true-image data. This technique expectes to be effective for the denoising of radiation. In order to demonstrate the feature filtering method, we make a pseudo-measured image generated from an ideal simulation of electron spectroscopy (using as the true-image data), and the noise-image data which make from the measured radiation noise convoluted with the pseudo-measured image (using as the noise-image data). Then, the ideal feature base is obtained by machine learning from the true-image data and the noise-image data, the feature filtering of the actually measured data is verified by using these the ideal feature base. In this report, we show the denoising performance of the feature filtering compared with "median filter" which is generally used for filtering of radiation noise.HEDS202

Ion species discrimination method by linear energy transfer measurement in Fujifilm BAS-SR Imaging Plate

We have developed a novel discrimination methodology to identify ions in multispecies beams with similar charge to mass ratios but different atomic numbers. After an initial separation by charge-to-mass ratio using co-linear electric and magnetic fields, individual ions can be discriminated by considering the Linear Energy Transfer and non-linear detector response of ions irradiating stimulable phosphor plate (Fujifilm imaging plate), by comparison with Monte-Carlo calculation. We apply the method to energetic multispecies laser-driven ion beams and use it to identify silver ions produced by the interaction between a high contrast, high intensity laser pulse and a sub-m silver foil target. We also show that this method can be used to calibrate imaging plate for arbitrary ion species without requiring individual calibration

Vieraea. Vol. 35

State-of-the-art high power laser facilities present numerous potential applications, including the generation of ultra-short and low emittance ion beams. Understanding the underlying laser-plasma interaction physics and resulting scaling to ultra-high intensities is of great importance for optimising such sources. We therefore present experimental data of proton acceleration in a sheath field using the ultra-high intensity J-KAREN-P laser (10 J, 40 fs, 5x1021 W/cm2), allowing investigation at the high-intensity frontier.A repetitive tape target was used to generate proton beams at a 0.1 Hz repetition rate limited only by the laser, allowing a systematic and comprehensive scan over laser parameters. Our laser-target system is able to regularly produce protons in excess of 40 MeV at the full repetition rate. We will demonstrate a slower than expected increase in proton energy with decreasing focal spot size, show that this is due to a reduced sheath lifetime for tight focal spots, and propose a new model which successfully predicts proton energies over a large range of focal spot sizes.We demonstrate that the laser accelerated electron temperature depends not only on laser intensity but also on focal-spot size, in which the restriction of the transverse acceleration distance causes saturation of the electron temperature at increasingly small foci. However, the accelerated electron beam profile becomes more collimated and asymmetric with small focal spots. Measurements of the proton beam show only limited benefit to using increasingly small focal spot sizes, and the best scaling for achieving higher maximum proton energies from sheath acceleration is achieved with increasing the pulse energy, rather than reducing the spot size or pulse length.Optics & Photonics International Congress 2019 (HEDS2019

Experimental investigation of sheath- driven proton acceleration scaling to the ultra-short pulse, ultra-high intensity regime

The behaviour of high power laser-plasma interaction from solid targets, and the resultant ion generation, at the extreme intensities available at state-of-the-art laser facilities is an important topic for realising potential applications. We will present experimental data investigating electron heating and proton acceleration in a sheath field using the ultra-high intensity, high contrast J- KAREN-P laser. Using a 10 J, 40 fs pulse focused to an intensity ~5x1021 Wcm-2 resulted in generation of protons up to 40 MeV at 0.1 Hz from a 5 μm steel tape target. The high repetition rate of the tape target allowed large statistically relevant investigations into the scaling of the electron and proton beam with laser energy, pulse length and spot size.We demonstrate that the laser accelerated electron temperature depends not only on laser intensity but also on focal-spot size, in which the restriction of the transverse acceleration distance causes saturation of the electron temperature at increasingly small foci. However, the accelerated electron beam profile becomes more collimated and asymmetric with small focal spots. Measurements of the proton beam show only limited benefit to using increasingly small focal spot sizes, and the best scaling for achieving higher maximum proton energies from sheath acceleration is achieved with increasing the pulse energy, rather than reducing the spot size or pulse length.JPS butsuri gakka

Electron heating and ion acceleration in sheaths from ultra-high intensity laser-solid interactions

The behaviour of high power laser-plasma interaction from solid targets, and the resultant ion generation, at the extreme intensities available at state-of-the-art laser facilities is an important topic for realising potential applications. We will present experimental data investigating electron heating and proton acceleration in a sheath field using the ultra-high intensity, high contrast J- KAREN-P laser. Using a 10 J, 40 fs pulse focused to an intensity ~5x1021 Wcm-2 resulted in generation of protons up to 40 MeV at 0.1 Hz from a 5 μm steel tape target. The high repetition rate of the tape target allowed large statistically relevant investigations into the scaling of the electron and proton beam with laser energy, pulse length and spot size.We demonstrate that the laser accelerated electron temperature depends not only on laser intensity but also on focal-spot size, in which the restriction of the transverse acceleration distance causes saturation of the electron temperature at increasingly small foci. However, the accelerated electron beam profile becomes more collimated and asymmetric with small focal spots. Measurements of the proton beam show only limited benefit to using increasingly small focal spot sizes, and the best scaling for achieving higher maximum proton energies from sheath acceleration is achieved with increasing the pulse energy, rather than reducing the spot size or pulse length.Imperial College London Plasma Physics Group Semina