Performance of the MALTA telescope van Rijnbach, Milou; Gustavino, Giuliano; Allport, Phil ...
European physical journal. C, Particles and fields,
07/2023, Letnik:
83, Številka:
7
Journal Article
Recenzirano
Odprti dostop
MALTA is part of the Depleted Monolithic Active Pixel sensors designed in Tower 180 nm CMOS imaging technology. A custom telescope with six MALTA planes has been developed for test beam campaigns at ...SPS, CERN, with the ability to host several devices under test. The telescope system has a dedicated custom readout, online monitoring integrated into DAQ with realtime hit map, time distribution and event hit multiplicity. It hosts a dedicated fully configurable trigger system enabling to trigger on coincidence between telescope planes and timing reference from a scintillator. The excellent time resolution performance allows for fast track reconstruction, due to the possibility to retain a low hit multiplicity per event which reduces the combinatorics. This paper reviews the architecture of the system and its performance during the 2021 and 2022 test beam campaign at the SPS North Area.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The ATLAS experiment will undergo a full replacement of its inner detector to face the challenges posed by the High Luminosity upgrade of the Large Hadron Collider (HL-LHC). The new Inner Tracker ...(ITk) will have to deal with extreme particle fluences. Due to its superior radiation hardness the 3D silicon sensor technology has been chosen to instrument the innermost pixel layer of ITk, which is the most exposed to radiation damage. Three foundries (CNM, FBK, and SINTEF), have developed and fabricated novel 3D pixel sensors to meet the specifications of the new ITk pixel detector. These are produced in a single-side technology on either Silicon On Insulator (SOI) or Silicon on Silicon (Si-on-Si) bonded wafers by etching both
n
- and
p
-type columns from the same side. With respect to previous generations of 3D sensors they feature thinner active substrates and smaller pixel cells of 50 × 50 and 25 × 100 µm
2
. This paper reviews the main design and technological issues of these novel 3D sensors, and presents their characterization before and after exposure to large radiation doses close to the one expected for the innermost layer of ITk. The performance of pixel modules, where the sensors are interconnected to the recently developed RD53A chip prototype for HL-LHC, has been investigated in the laboratory and at beam tests. The results of these measurements demonstrate the excellent radiation hardness of this new generation of 3D pixel sensors that enabled the project to proceed with the pre-production for the ITk tracker.
In this article, a low-power, radiation-hard front-end circuit for monolithic pixel sensors, designed to meet the requirements of low noise and low pixel-to-pixel variability, the key features to ...achieve high detection efficiencies, is presented. The sensor features a small collection electrode to achieve a small capacitance (<5 fF) and allows full CMOS in-pixel circuitry. The circuit is implemented in the 180-nm CMOS imaging technology from the TowerJazz foundry and integrated into the MALTA2 chip, which is part of a development that targets the specifications of the outer pixel layer of the ATLAS Inner Tracker upgrade at the LHC. One of the main challenges for monolithic sensors is a radiation hardness up to 10 15 1-MeV <inline-formula> <tex-math notation="LaTeX">\text {n}_{\text {eq}}/\text {cm}^{{2}} </tex-math></inline-formula> non-ionizing energy loss (NIEL) and 80 Mrad total ionizing dose (TID) required for this application. Tests up to <inline-formula> <tex-math notation="LaTeX">{3} \cdot {10}^{15} </tex-math></inline-formula> 1-MeV <inline-formula> <tex-math notation="LaTeX">\text {n}_{\text {eq}}/\text {cm}^{{2}} </tex-math></inline-formula> and 100 Mrad were performed on the MALTA2 sensor and front-end circuit, which still show good performance even after these levels of irradiation, promising for even more demanding applications such as the future experiments at the high-luminosity large hadron collider (HL-LHC).
MALTA monolithic pixel sensors in TowerJazz 180 nm technology Solans Sánchez, C.; Allport, P.; Asensi Tortajada, I. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2023, Letnik:
1057
Journal Article
Recenzirano
Odprti dostop
Depleted Monolithic Active Pixel Sensors are of highest interest at the HL-LHC and beyond for the replacement of the Pixel trackers in the outermost layers of experiments where the requirement on ...total area and cost effectiveness is much bigger. They aim to provide high granularity and low material budget over large surfaces with ease of integration. Our research focuses on MALTA, a radiation hard DMAPS with small collection electrode designed in TowerJazz 180 nm CMOS imaging technology and asynchronous read-out. Latest prototypes are radiation hard up to 2 × 1015 1 MeV neq/cm2 with a time resolution better than 2 ns.
MALTA is a depleted monolithic active pixel sensor (DMAPS) developed in the Tower Semiconductor 180-nm CMOS imaging process. Monolithic CMOS sensors offer advantages over current hybrid imaging ...sensors in terms of both increased tracking performance due to lower material budget and ease of integration and construction costs due to the integration of read-out and active sensor into one ASIC. Current research and development efforts are aimed toward radiation hard designs up to 100 Mrad in total ionizing dose (TID) and <inline-formula> <tex-math notation="LaTeX">1\,\, \times 10 ^{15}~1~\text {MeV}\text {n}_{\text {eq}}/\text {cm}^{2} </tex-math></inline-formula> in nonionizing energy loss (NIEL). The design of the MALTA sensors was specifically chosen to achieve radiation hardness up to these requirements and satisfy current and future collider constraints. The current MALTA pixel architecture uses small electrodes which provide less noise, higher signal voltage, and a better power-to-performance ratio. To counteract the loss of efficiency in pixel corners, modifications to the Tower process have been implemented. The MALTA sensors have been tested during the 2021 and 2022 SPS CERN Test Beam in the MALTA telescope. The telescope ran for the whole duration of the beam time and took data to characterize the novel MALTA2 variant and the performance of irradiated samples in terms of efficiency and cluster size. These campaigns show that MALTA is an interesting prospect for HL-LHC and beyond collider experiments, providing both very good tracking capabilities and radiation hardness in harsh radiation environments.
The upgrade of the MALTA DMAPS designed in Tower 180 nm CMOS Imaging process will implement the numerous modifications, as well as front-end changes in order to boost the charge collection efficiency ...after the targeted fluence of 1x10151MeVneq/cm2. The effectiveness of these changes have been demonstrated in recent measurements with a small-scale Mini-MALTA demonstrator chip. Multiple changes in the digital periphery are proposed: The asynchronous address generator will be revised to provide more control over the pulse length. The Synchronization memory will be upgraded with the goal of achieving a sub-nanosecond timing resolution. Serial chip to chip data transfer will be prototyped, in order to gauge the plausibility of implementation on a future full sized chip. Apart from these changes, research of the overall sensor architecture will be discussed as well.
Abstract
The High Luminosity LHC (HL-LHC) upgrade requires the
planned Inner Tracker (ITk) of the ATLAS detector to tolerate
extremely high radiation doses. Specifically, the innermost parts of
the ...pixel system will have to withstand radiation fluences above
1 × 10
16
n
eq
cm
-2
. Novel 3D silicon pixel
sensors offer a superior radiation tolerance compared to
conventional planar pixel sensors, and are thus excellent candidates
for the innermost parts of the ITk. This paper presents studies of
3D pixel sensors with pixel size 50 × 50 μm
2
mounted
on the RD53A prototype readout chip. Following a description of the
design and fabrication steps, Test Beam results are presented for
unirradiated as well as heavily irradiated sensors. For particles
passing at perpendicular incidence, it is shown that average
efficiencies above 96% are reached for sensors exposed to fluences
of 1 × 10
16
n
eq
cm
-2
when biased to 80 V.
Abstract
The MALTA family of Depleted Monolithic Active Pixel Sensor (DMAPS) produced in Tower 180 nm CMOS technology targets radiation hard applications for the HL-LHC and beyond. Several process ...modifications and front-end improvements have resulted in radiation hardness up to 2 × 10
15
1 MeV n
eq
/cm
2
and time resolution below 2 ns, with uniform charge collection efficiency across the pixel of size 36.4 × 36.4 μm
2
with a 3 μm
2
electrode size. The MALTA2 demonstrator produced in 2021 on high-resistivity epitaxial silicon and on Czochralski substrates implements a new cascoded front-end that reduces the RTS noise and has a higher gain. This contribution shows results from MALTA2 on timing resolution at the nanosecond level from the CERN SPS test-beam campaign of 2021.
PDF
