A. Paladino

The PixFEL project: development of advanced X-ray pixel detectors for application at future FEL facilities

The PixFEL project aims to develop an advanced X-ray camera for imaging suited for the demanding requirements of next generation free electron laser (FEL) facilities. New technologies can be deployed to boost the performance of imaging detectors as well as future pixel devices for tracking. In the first phase of the PixFEL project, approved by the INFN, the focus will be on the development of the microelectronic building blocks, carried out with a 65 nm CMOS technology, implementing a low noise analog front-end channel with high dynamic range and compression features, a low power ADC and high density memory. At the same time PixFEL will investigate and implement some of the enabling technologies to assembly a seamless large area X-ray camera composed by a matrix of multilayer four-side buttable tiles. A pixel matrix with active edge will be developed to minimize the dead area of the sensor layer. Vertical interconnection of two CMOS tiers will be explored to build a four-side buttable readout chip with small pixel pitch and all the on-board required functionalities. The ambitious target requirements of the new pixel device are: single photon resolution, 1 to 104 photons @ 1 keV to 10 keV input dynamic range, 10-bit analog to digital conversion up to 5 MHz, 1 kevent in-pixel memory and 100 μm pixel pitch. The long term goal of PixFEL will be the development of a versatile X-ray camera to be operated either in burst mode (European XFEL), or in continuous mode to cope with the high frame rates foreseen for the upgrade phase of the LCLS-II at SLAC.

Construction and test of the first Belle II SVD ladder implementing the origami chip-on-sensor design

The Belle II Silicon Vertex Detector comprises four layers of double-sided silicon strip detectors (DSSDs), consisting of ladders with two to five sensors each. All sensors are individually read out by APV25 chips with the Origami chip-on-sensor concept for the central DSSDs of the ladders. The chips sit on flexible circuits that are glued on the top of the sensors. This concept allows a low material budget and an efficient cooling of the chips by a single pipe per ladder. We present the construction of the first SVD ladders and results from precision measurements and electrical tests.

Design and TCAD simulations of planar active-edge pixel sensors for future XFEL applications

We report on the design and TCAD simulations of planar active-edge pixel sensors within the INFN PixFEL project. These devices are intended as one of the building blocks for the assembly of a multilayer, four-side buttable tile for X-ray imaging applications in future Free Electron Laser facilities. The requirements in terms of very wide dynamic range and tolerance to extremely high ionizing radiation doses call for high operation voltages. A comprehensive TCAD simulation study is presented, aimed at the best trade-offs between the minimization of the edge region size and the sensor breakdown voltage.

Belle II silicon vertex detector

The Belle II experiment at the SuperKEKB collider in Japan is designed to indirectly probe new physics using approximately 50 times the data recorded by its predecessor. An accurate determination of the decay-point position of subatomic particles such as beauty and charm hadrons as well as a precise measurement of low-momentum charged particles will play a key role in this pursuit. These will be accomplished by an inner tracking device comprising two layers of pixelated silicon detector and four layers of silicon vertex detector based on double-sided microstrip sensors. We describe herein the design, prototyping and construction efforts of the Belle-II silicon vertex detector.

PixFEL: Enabling technologies, building blocks and architectures for advanced X-ray pixel cameras at the next generation FELs

The PixFEL project is conceived as the first stage of a long term research program aiming at the development of advanced instrumentation for coherent X-ray diffractive imaging applications at the next generation free electron laser (FEL) facilities. The project aims at substantially advancing the state-of-the-art in the field of 2D X-ray imaging through the adoption of cutting-edge microelectronic technologies and innovative design and architectural solutions. For this purpose, the collaboration is developing the fundamental microelectronic building blocks (low noise analog front-end with dynamic compression feature, high resolution, low power ADC, high density memories) and investigating and implementing the enabling technologies (active edge pixel sensors, high density and low density through silicon vias) for the assembly of a multilayer four side buttable tile. The building block design is being carried out in a 65 nm CMOS technology. The ambitious goal of the research program is the fabrication of an X-ray camera with single photon resolution, 1 to 104 photons @ 1 keV to 10 keV input dynamic range, 1 kevent in-pixel memory, 100 μm pixel pitch, and the capability to be operated at the fast (1 MHz or larger) rates foreseen for the future X-ray FEL machines.

PixFEL: development of an X-ray diffraction imager for future FEL applications

A readout chip for diffraction imaging applications at new generation X-ray FELs (Free Electron Lasers) has been designed in a 65~nm CMOS technology. It consists of a

PFM2: A 32 × 32 readout chip for the PixFEL X-ray imager demonstrator

32 \times 32

First Experimental Results on Active and Slim-Edge Silicon Sensors for XFEL

matrix, with square pixels and a pixel pitch of

PFM2: a 32 × 32 processor for X-ray diffraction imaging at FELs

110\ \mu m

A 10 bit resolution readout channel with dynamic range compression for X-ray imaging at FELs

. Each cell includes a low-noise charge sensitive amplifier (CSA) with dynamic signal compression, covering an input dynamic range from 1 to