Speaker
Description
A. Sharma$^1$, G. D'Amen$^2$, F. Bouyjou$^3$, O. Brand-Foissac$^1$, V. Chaumat$^1$, W. Chen$^2$, S. Conforti$^4$, T. Cornet$^1$, F. Dulucq$^4$, S. Extier$^4$, G. Giacomini$^2$, K. Hara$^5$, A. Ikbal$^6$, T. Imamura$^5$, M. Idzik$^7$, A. Jentsch$^2$, S. Kita$^5$, B.-Y. Ky$^1$, D. Marchand$^1$, J. Moron$^7$, K. Nakamura$^8$, S. Paul$^2$, P. Shanmuganathan$^2$, N. Seguin-Moreau$^4$, L. Serin$^1$, D. Thienpont$^4$, C. de La Taille$^4$, A.-S. Torrento-Coello$^1$, P. Tribedy$^2$, A. Tricoli$^2$, A. Verplancke$^4$
$^1$Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay 91405, France
$^2$Brookhaven National Laboratory, 11973 Upton, NY, U.S.A.
$^3$Université Paris-Saclay, CEA, IRFU, Centre CEA Paris-Saclay, Gif-sur-Yvette 91191, France
$^4$OMEGA, CNRS, École Polytechnique, Institut Polytechnique de Paris, Palaiseau 91120, France
$^5$University of Tsukuba, 1-1-1 Tennodai, Tsukuba, 305-8571, Ibaraki, Japan
$^6$Kent State University, 44242 Kent, OH, U.S.A.
$^7$AGH University of Science and Technology, al. Adama Mickiewicza, 30-059 Kraków, Poland
$^8$High Energy Research Organization (KEK), 1-1 Oho, Tsukuba, 305-0801, Ibaraki, Japan
Finding the answers to the long-standing questions, such as, emergence of mass and spin of the proton from partons, saturation of gluon density, and gluon momentum distribution inside the proton and nuclei, motivated the EIC [1] to be developed at Brookhaven National Laboratory, USA. The first EIC detector, ePIC (electron Proton-Ion Collision experiment), is comprised of a central barrel detector, as well as extensive beamline detectors in the outgoing electron (far-backward) and hadron (far-forward) beam directions. The far-forward (FF) detectors include Roman pots, which are placed inside vacuum and are intended to detect protons and ions scattered at very small angles (~ 5 mrad) in the forward direction, at ~30m downstream from the interaction point. The main goal of the FF detectors is to tag exclusive and diffractive events and to reconstruct their transverse momentum with a resolution of ~ 10 MeV/c. This is obtained by developing a new generation of 4D tracking sensors, pixelated AC-LGADs (capacitively-coupled Low-Gain Avalanche Diode, pixel of 500x500 $\mu$m$^2$) [2][3] capable of providing the required spatial (less than 50 $\mu$m relying on charge sharing among pixels) and timing (~ 30 ps) resolutions. After these AC-LGADs have been read-out using ALTIROC0 [4] as a first attempt, an optimized read-out chip, EICROC (32x32 pads), is being designed by OMEGA and the characterization of the first prototype, EICROC0 (4x4 pads) [5], coupled to an AC-LGAD sensor is being performed at IJCLab. The EICROC0 is a system-on-chip with analog and digital processing including for each of the 16 channels a fast low-noise trans-impedance preamplifier, followed by two paths: a fast path with a discriminator connected to a 10-bit Time-to-Digital Converter (CEA/Irfu) for time measurement (ToA) with a 25 ps accuracy; and a slow path with shaper connected to an 8-bit 40 MHz successive approximation Analog-to-Digital Converter (AGH Krakow) providing amplitudes. The performances of pixelated AC-LGAD sensors read-out by EICROC0, obtained from preamplifier as well as digital (TDC and ADC) data and relying on measurements with the internal charge injection system, a Beta source and an infrared laser, will be presented.
Acknowledgement:
This work is benefitting from support from the French Agence Nationale de la Recherche (ANR), under grant ANR-24-CE31-5571 (project ROAD_4_EIC).
References:
[1] R. Abdul Khalek et al., “Science Requirements and Detector Concepts for the Electron-Ion Collider: EIC Yellow Report”, Nucl. Phys. A 1026 (2022).
[2] G. Giacomini et al., “Fabrication and performance of AC-coupled LGADs”, JINST 14 (2019), P09004.
[3] S. Kita et al., “Optimization of capacitively coupled Low Gain Avalanche Diode (AC-LGAD) sensors for precise time and spatial resolution”, NIM A 1048 (2023) 168009.
[4] G. D'Amen et al., “Signal formation and sharing in AC-LGADs using the ALTIROC0 front-end chip”, JINST 17 (2022) P11028.
[5] A. Verplancke et al., “EICROC: an ASIC to read-out the AC-LGAD sensors for the Electron-Ion Collider (EIC)”, contribution to the proceedings of the Topical Workshop on Electronics for Particle Physics, Sept. 30th – Oct. 04th, 2024, Glasgow, UK, to be published in JINST 2025.
