ESR 09: Roberto Cardella

Host Institution: 
CERN, Geneva, Switzerland
Design, assembly and test of large area CMOS pixel detector prototypes, for the ATLAS experiment.
MSc in Electronic Engineering, Universita degli Studi di Catania, Italy, 07/2016

Hello! I am Roberto, I have studied electronics engineering at the University of Catania where I took my BSc and MSc in July 2013 and 2016 respectively. During the last year of my university studies, I came at CERN as a technical student working in the n_ToF experiment, where  I worked on JAVA development, and I have designed, produced and tested some electronics for the upgrade of TAC detector (Total Absorption Calorimeter).

I was sixteen when I came visiting CERN with my school, and after ten years, in September 2016 I joined STREAM as a CERN fellow, and I am doing my PhD at the University of Oslo.

I love to work in a challenging environment and to experiment. I like to put myself all the time pursuing new goals, especially in fields that I have never explored before.

My mantra is "move and never stay steady". I love to explore the world and meet people from all over the world getting in touch with different cultures and lifestyles. I love my job because it allows me to do it when I work and even when I do not.

Research at STREAM: 

As Early Stage Researcher (ESR 9 WP4) in the STREAM ITN working at CERN and doing my PhD at the University of Oslo, I contribute to the development and test of novel pixel sensors, comprising laboratory measurements, irradiations campaigns and test beams. My particular contribution to the project is the design and validation of a large area monolithic pixel detector, which should meet the ATLAS inner tracker specifications, aiming to reduce the material budget and improve the overall performance.


The first part of my work in the project has been directly related to the design of a monolithic pixel detector called MALTA (Monolithic pixel sensor from ALICE To ATLAS). My contribution to this chip is the design of an output buffer, which allows sending data from the pixel detector to the external world at high speed (5 Gbit per second) with low power consumption. The name of this circuit is LAPA (LVDS for Atlas Pixel Apparatus). The buffer design is directly related to the assembly of a large area pixel detector. Indeed, it has to match the data rate requirements of a module of four-pixel sensors. I have integrated the buffer into the MALTA chip and designed a test chip with ten input/output buffer channels to fully test its functionality.

Sequentially, I have started with the preparation and design of test cards for single chips as well as modules, in collaboration with the rest of the testing team. I am currently involved in the test of both MALTA and LAPA, with a particular focus on irradiation and test beam, for what concern the organisation and the actual tests.

The characterization of MALTA CMOS chip will allow me to investigate the possible connections to build a four-sensor module, minimizing the dead area of the full detector, which is one objective of the project.



Host Institution and Secondment Topic 

Expected secondment period

 University of Oslo (NO), Science ethics course

10 days in May 2017

University of Glasgow (UK), Design of testboard of LAPA chip for high-speed data transmission

One week in July 2017

UniBonn (DE),  Test beam measurement on MALTA

One week in March 2018

Univ. of Glasgow (UK), Test of LAPA chip for high-speed data transmission and MALTA  10 days in June 2018




In the high energy physic experiment, a crucial aspect of the detectors is the material budget and the coverage of the full area of an event. The usage of novel interconnection technologies in combination with monolithic CMOS sensors would give a substantial contribution on the pursuit of improving this two aspects of the detectors, with an expected reduction of the cost.

The development of this technologies, driven by physics research, would allow increasing the possibility of discoveries. Moreover, creating more expertise and structures to develop such sensors would enable introducing their usage in consumer and medical applications, such as imaging and cameras, with improved performance and reduced costs.


Topical Workshop on Electronics for Particle Physics (TWEPP2017), , Santa Cruz (California US)
9th International Workshop on Semiconductor Pixel Detectors for Particles and Imaging, Taipei, Taiwan
Monolithic Pixel Development in TowerJazz 180nm CMOS for the outer pixel layers in the ATLAS experiment
CMOS monolithic pixel sensors based on the column-drain architecture for the HL-LHC upgrade
Depleted fully monolithic CMOS pixel detectors using a column based readout architecture for the ATLAS Inner Tracker upgrade
LAPA, a 5 Gb/s modular pseudo-LVDS driver in 180 nm CMOS with capacitively coupled pre-emphasis
MALTA: an asynchronous readout CMOS monolithic pixel detector for the ATLAS High-Luminosity upgrade
Development of the monolithic "MALTA" CMOS sensor for the ATLAS ITK outer pixel layer
Measurement results of the MALTA monolithic pixel detector
The Malta CMOS pixel detector prototype for the ATLAS Pixel ITK
MALTA: a CMOS pixel sensor with asynchronous readout for the ATLAS High-Luminosity upgrade
Mini-MALTA: Radiation hard pixel designs for small-electrode monolithic CMOS sensors for the High Luminosity LHC

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