Charge calibration of MALTA2, a radiation hard depleted monolithic active pixel sensor

Lucian Fasselt; Ignacio Asensi Tortajada; Prafulla Behera; Dumitru Vlad Berlea; Daniela Bortoletto; Craig Buttar; Valerio Dao; Ganapati Dash; Leyre Flores Sanz de Acedo; Martin Gazi; Laura Gonella; Vicente González; Sebastian Haberl; Tomohiro Inada; Pranati Jana; Long Li; Heinz Pernegger; Petra Riedler; Walter Snoeys; Carlos Solans Sánchez; Milou van Rijnbach; Marcos Vázquez Núñez; Anusree Vijay; Julian Weick; Steven Worm

doi:10.1016/j.nima.2025.170972

Charge calibration of MALTA2, a radiation hard depleted monolithic active pixel sensor

Lucian Fasselt
, Ignacio Asensi Tortajada
, Prafulla Behera
, Dumitru Vlad Berlea
, Daniela Bortoletto
, Craig Buttar
, Valerio Dao
, Ganapati Dash
, Leyre Flores Sanz de Acedo
, Martin Gazi
, Laura Gonella
, Vicente González
, Sebastian Haberl
, Tomohiro Inada
, Pranati Jana
, Long Li
, Heinz Pernegger
, Petra Riedler
, Walter Snoeys
, Carlos Solans Sánchez

Milou van Rijnbach, Marcos Vázquez Núñez, Anusree Vijay, Julian Weick, Steven Worm

Physics and Astronomy

German Electron Synchrotron
Humboldt University of Berlin
CERN
Indian Institute of Technology Madras
University of Oxford
University of Glasgow
University of Trieste
University of Valencia
University of Birmingham

Research output: Contribution to journal › Article › peer-review

1 Scopus citations

Abstract

MALTA2 is a depleted monolithic active pixel sensor (DMAPS) designed for tracking at high rates and typically low detection threshold of 200e⁻. Threshold calibration is crucial to understanding the charge collection in the pixel. A simple procedure is developed to calibrate the threshold to unit electrons making use of a dedicated charge injection circuit and an Fe-55 source with dominant charge deposition of 1611e⁻. The injection voltage corresponding to the signal under exposure of Fe-55 is determined and serves as the basis for charge calibration. The charge injection circuit incorporates a capacitance with design value of C_inj=230aF. Experimentally, the average capacitance value for non-irradiated samples is found to be C_inj,exp=255±35aF and varies between sensors by 14% in terms of standard deviation. The deviation from the design value as well as among sensors motivates the need for the presented calibration procedure, which is proposed to be performed for each MALTA2 sensor and reduces the uncertainty down to 3% depending on the sensor.

Original language	English
Article number	170972
Journal	Nuclear Inst. and Methods in Physics Research, A
Volume	1082
DOIs	https://doi.org/10.1016/j.nima.2025.170972
State	Published - Feb 2026

Keywords

Charge calibration
DMAPS
High-energy physics
Tracking

Access to Document

10.1016/j.nima.2025.170972

Cite this

Fasselt, L., Asensi Tortajada, I., Behera, P., Berlea, D. V., Bortoletto, D., Buttar, C., Dao, V., Dash, G., Flores Sanz de Acedo, L., Gazi, M., Gonella, L., González, V., Haberl, S., Inada, T., Jana, P., Li, L., Pernegger, H., Riedler, P., Snoeys, W., ... Worm, S. (2026). Charge calibration of MALTA2, a radiation hard depleted monolithic active pixel sensor. Nuclear Inst. and Methods in Physics Research, A, 1082, Article 170972. https://doi.org/10.1016/j.nima.2025.170972

@article{6ba2ae1cd9e64534a9ccc2b98d9e9a8d,

title = "Charge calibration of MALTA2, a radiation hard depleted monolithic active pixel sensor",

abstract = "MALTA2 is a depleted monolithic active pixel sensor (DMAPS) designed for tracking at high rates and typically low detection threshold of 200e−. Threshold calibration is crucial to understanding the charge collection in the pixel. A simple procedure is developed to calibrate the threshold to unit electrons making use of a dedicated charge injection circuit and an Fe-55 source with dominant charge deposition of 1611e−. The injection voltage corresponding to the signal under exposure of Fe-55 is determined and serves as the basis for charge calibration. The charge injection circuit incorporates a capacitance with design value of Cinj=230aF. Experimentally, the average capacitance value for non-irradiated samples is found to be Cinj,exp=255±35aF and varies between sensors by 14\% in terms of standard deviation. The deviation from the design value as well as among sensors motivates the need for the presented calibration procedure, which is proposed to be performed for each MALTA2 sensor and reduces the uncertainty down to 3\% depending on the sensor.",

keywords = "Charge calibration, DMAPS, High-energy physics, Tracking",

author = "Lucian Fasselt and \{Asensi Tortajada\}, Ignacio and Prafulla Behera and Berlea, \{Dumitru Vlad\} and Daniela Bortoletto and Craig Buttar and Valerio Dao and Ganapati Dash and \{Flores Sanz de Acedo\}, Leyre and Martin Gazi and Laura Gonella and Vicente Gonz{\'a}lez and Sebastian Haberl and Tomohiro Inada and Pranati Jana and Long Li and Heinz Pernegger and Petra Riedler and Walter Snoeys and \{Solans S{\'a}nchez\}, Carlos and \{van Rijnbach\}, Milou and \{V{\'a}zquez N{\'u}{\~n}ez\}, Marcos and Anusree Vijay and Julian Weick and Steven Worm",

note = "Publisher Copyright: {\textcopyright} 2025 The Authors",

year = "2026",

month = feb,

doi = "10.1016/j.nima.2025.170972",

language = "English",

volume = "1082",

journal = "Nuclear Inst. and Methods in Physics Research, A",

issn = "0168-9002",

}

Fasselt, L, Asensi Tortajada, I, Behera, P, Berlea, DV, Bortoletto, D, Buttar, C, Dao, V, Dash, G, Flores Sanz de Acedo, L, Gazi, M, Gonella, L, González, V, Haberl, S, Inada, T, Jana, P, Li, L, Pernegger, H, Riedler, P, Snoeys, W, Solans Sánchez, C, van Rijnbach, M, Vázquez Núñez, M, Vijay, A, Weick, J & Worm, S 2026, 'Charge calibration of MALTA2, a radiation hard depleted monolithic active pixel sensor', Nuclear Inst. and Methods in Physics Research, A, vol. 1082, 170972. https://doi.org/10.1016/j.nima.2025.170972

TY - JOUR

T1 - Charge calibration of MALTA2, a radiation hard depleted monolithic active pixel sensor

AU - Fasselt, Lucian

AU - Asensi Tortajada, Ignacio

AU - Behera, Prafulla

AU - Berlea, Dumitru Vlad

AU - Bortoletto, Daniela

AU - Buttar, Craig

AU - Dao, Valerio

AU - Dash, Ganapati

AU - Flores Sanz de Acedo, Leyre

AU - Gazi, Martin

AU - Gonella, Laura

AU - González, Vicente

AU - Haberl, Sebastian

AU - Inada, Tomohiro

AU - Jana, Pranati

AU - Li, Long

AU - Pernegger, Heinz

AU - Riedler, Petra

AU - Snoeys, Walter

AU - Solans Sánchez, Carlos

AU - van Rijnbach, Milou

AU - Vázquez Núñez, Marcos

AU - Vijay, Anusree

AU - Weick, Julian

AU - Worm, Steven

PY - 2026/2

Y1 - 2026/2

N2 - MALTA2 is a depleted monolithic active pixel sensor (DMAPS) designed for tracking at high rates and typically low detection threshold of 200e−. Threshold calibration is crucial to understanding the charge collection in the pixel. A simple procedure is developed to calibrate the threshold to unit electrons making use of a dedicated charge injection circuit and an Fe-55 source with dominant charge deposition of 1611e−. The injection voltage corresponding to the signal under exposure of Fe-55 is determined and serves as the basis for charge calibration. The charge injection circuit incorporates a capacitance with design value of Cinj=230aF. Experimentally, the average capacitance value for non-irradiated samples is found to be Cinj,exp=255±35aF and varies between sensors by 14% in terms of standard deviation. The deviation from the design value as well as among sensors motivates the need for the presented calibration procedure, which is proposed to be performed for each MALTA2 sensor and reduces the uncertainty down to 3% depending on the sensor.

AB - MALTA2 is a depleted monolithic active pixel sensor (DMAPS) designed for tracking at high rates and typically low detection threshold of 200e−. Threshold calibration is crucial to understanding the charge collection in the pixel. A simple procedure is developed to calibrate the threshold to unit electrons making use of a dedicated charge injection circuit and an Fe-55 source with dominant charge deposition of 1611e−. The injection voltage corresponding to the signal under exposure of Fe-55 is determined and serves as the basis for charge calibration. The charge injection circuit incorporates a capacitance with design value of Cinj=230aF. Experimentally, the average capacitance value for non-irradiated samples is found to be Cinj,exp=255±35aF and varies between sensors by 14% in terms of standard deviation. The deviation from the design value as well as among sensors motivates the need for the presented calibration procedure, which is proposed to be performed for each MALTA2 sensor and reduces the uncertainty down to 3% depending on the sensor.

KW - Charge calibration

KW - DMAPS

KW - High-energy physics

KW - Tracking

UR - https://www.scopus.com/pages/publications/105015769837

U2 - 10.1016/j.nima.2025.170972

DO - 10.1016/j.nima.2025.170972

M3 - Article

AN - SCOPUS:105015769837

SN - 0168-9002

VL - 1082

JO - Nuclear Inst. and Methods in Physics Research, A

JF - Nuclear Inst. and Methods in Physics Research, A

M1 - 170972

ER -

Charge calibration of MALTA2, a radiation hard depleted monolithic active pixel sensor

Abstract

Keywords

Access to Document

Other files and links

Fingerprint

Cite this