CMR Manganite Sensors for Total Energy Measurements of the Linear Coherent Light Source Pulsed X-ray Laser

We are developing CMR manganite thin film bolometric sensors for total energy measurements of the Linear Coherent Light Source (LCLS) pulsed free electron x-ray laser (FEL). This application requires the sensor array to be fabricated on a low Z substrate capable of withstanding the pulse impact of 2 mJ in $\sim $ 200 femtoseconds, without the thermal expansion exceeding the yield strength, when the back side of the substrate is irradiated. Si is a potential candidate for meeting this requirement though its stability for long term exposure is a concern that needs to be tested. Optimal operating temperature of the sensor is estimated to be $\sim $ 100 K-200 K, based on finite element simulations of the temperature evolution in the sensor pixel. Our initial work has identified Nd $_{1-x}$ Sr$_{x}$ MnO$_{3}$ as the manganite material suitable for the LCLS sensor. We will present our materials development efforts towards LCLS sensor design as well as simulations of the sensor response.