Summary:
The previous project D_RD_02 allowed a ‘proof of principle’ of MPGDs (Micromegas and GEMs) for the electron amplification and readout of a TPC for the Linear Collider. The resolution of such an apparatus was understood and shown to be adequate, and the operation in a beam was demonstrated. Since 2013, a new project was started, as a preparatory step toward the construction of a TPC for the ILD experiment. Integration aspects are now being intensively worked on, including cooling, distortion mitigation and correction, electronics design, gating and other issues, as well as the definition of criteria for the technology choice.

French members:
S. Ganjour, D. Attié, P. Colas, I. Giomataris, S. Joshi, M. Titov, B. Tuchming

Japanese members:
K. Fujii, Y. Aoki, T. Fusayasu, K. Kato, M. Kobayashi, T. Matsuda, S. Narita, K. Negishi, A. Shoji, A. Sugiyama, T. Takahashi, T. Watanabe, K. Yumino, J. Nakajima

References:
[1] LCTPC Collaboration (David Attié, et al.), "A Time Projection Chamber with GEM-Based Readout", Nucl.Instrum.Meth. A856 (2017) 109-118 [2] W. Wang, ‘A Large Micromegas TPC for the ILC’, Thesis, Université Paris Sud (June 2013)
[3] R. Yonamine, K. Fujii, K. Ikematsu, A. Ishikawa, T. Fusayasu, P. Gros, Y. Kato and S. Kawada et al., “Spatial resolutions of GEM TPC.A novel theoretical formula and its comparison to latest beam test data”, JINST 9, C03002 (2014)
[4] P. Gros, K. Fujii, T. Fusayasu, Y. Kato, S. Kawada, M. Kobayashi, T. Matsuda and O. Nitoh et al., “Blocking positive ion backflow using a GEM gate: experiment and simulations,” JINST 8, C11023 (2013)

Websites:
http://irfu.cea.fr/ILC-TPC/
http://www-jlc.kek.jp/jlc/en/subg/tpc
http://www-hep.phys.saga-u.ac.jp/ILC-TPC/

Summary:
Our aim within the FJPPL is to develop and improve, around French and Japanese collaborators at LAL Orsay, KEK and Tsukuba University, respectively, a strong expertise on tracking detectors for future experiments, with international visibility. The detector upgrade programs underway in ATLAS for HL-LHC will be occasions to improve and optimize the planar pixel technology, which is a particularly well established technology for vertex detectors. The challenge consists in building more granular and thinner P doped sensor devices while keeping the goal of achieving cost effective solutions for large surfaces of sensitive material. This technology, even if it is mature, still needs to prove sufficient radiation hardness in the innermost region, close to the HL-LHC beam crossing environment. The activity within the project includes several of the critical tasks needed to develop this technology.

French members:
R. Tanaka, A. Lounis, M. Escalier, L. Huo

Japanese members:
K. Hara, K. Nakamura, Y. Unno

References:
[1] Achievements of the ATLAS upgrade Planar Pixel Sensors R&D Project, Journal of Instrumentation, JINST 10 C01027, 21 Jan. 2015
[2] Development of novel n+-in-p silicon planar pixel sensors for HL-LHC, Nuclear Instruments and Methods A699 (2013) 72-77
[3] Evaluation of novel KEK/HPK n-in-p pixel sensors for ATLAS upgrade with testbeam, Nuclear Instruments and Methods A699 (2013) 78-83
[4] Leading edge of the technological developments of Planar Pixel Sensors and prospects for ATLAS HL-LHC, A. Lounis, IEEE seoul 2013, proceedings, 22 Nov. 2013

http://hep-www.px.tsukuba.ac.jp/~hara/PbulkPixel.html

Summary:
A research program outlined in this proposal aims to advance the development of silicon detector, focusing on the technology that achieve O(10) picoseconds time resolution for minimum-ionizing particles (MIP) together with a spatial resolution of the order of O(10) microns, to implement a versatile testing system for prototype characterization, and to design readout electronics that can match the sensor layout and performance. IJCLab has expertise of TCAD simulation and CMOS readout chip (ASIC) development and testing. The AC-LGAD sensors developed by KEK has been tested using discrete amplifier PCB and will not work for larger size (the larger number of channel) prototype. ASIC-based amplifier chip will be developed by IJCLab. The experimental results are needed to be compared to dedicated TCAD simulations carried out by KEK and IJCLab. We plan to exchange students to discuss the development of the devices and to use facilities which are located in Paris and Japan. To perform more realistic TCAD simulation, the doping concentration and the depth profile must be measured by using Secondary Ion Mass Spectrometry (SIMS). IJCLab group has an experience to use the SIMS facility in Versailles. For future high-energy collider experiments, we need to develop sensors capable of surviving does of about 1x1016neq/cm2. CYRIC facilities in Japan will be used as a radiation facility for the commonly developed modules.

French members:
R. Tanaka, A. Lounis, Y. Khwaira, M. Cohen-Solal

Japanese members:
K. Nakamura, K. Hara, T. Ueda, S. Kita

References:
[1] Koji Nakamura, Sayuka Kita, Tatsuki Ueda, Kazuhiko Hara, and Hisanori Suzuki, "First Prototype of Finely Segmented HPK AC-LGAD Detectors", JPS Conf. Proc. 34, 010016 (2021) [9 pages], Proceedings of the 29th International Workshop on Vertex Detectors (VERTEX2020)

Summary:
The IPHC and KEK groups involved in the development of monolithic active pixel sensors in two different technologies, SOI and CMOS, have a common interest in developping a pixel sensor for an upgrade of the Belle II vertex detector [1]. The upgraded detector shall allow to decrease the occupancy by order of magnitudes compared to the current system, even at the nominal SuperKEKB instantaneous luminosity (~6e35 cm-2.s-1). Though the SOI [2] and CMOS [3] approaches differ in their solutions, especially regarding the critical treatment of the timing information associated to each particle hit, they face common challenges like simulation and accurate testing under real conditions [4]. The collaboration within this project will help both groups to optimize their proposals for the benefit of the Belle II collaboration.

French members:
J. Baudot, T. Fillinger, C. Finck, C. Hu-Guo, M. Kachel, I. Ripp-Baudot

Japanese members:
T. Tsuboyama, Y. Arai, A. Ishikawa, T. Miyoshi, M. Yamada

References:
[1] J. Baudot, Upgrade of the vertex detector of the Belle II experiment, Vertex 2020, https://indico.cern.ch/event/895924.
[2] A. Ishikawa, New Pixel Detector Concept 'DuTiP' for Belle II Upgrade and the ILC with an SOI Technology, HTSD12 2019, https://indico.cern.ch/event/803258.
[3] T. Fillinger, Detector simulation for a potential upgrade of the vertex detector of the Belle II experiment, Epiphany Conference on Future of Particle Physics 2021, https://indico.cern.ch/event/934666.
[4] K. Hanagaki, KEK test beamline construction plan, The Physical Society of Japan Autumn Conference 2020, https://kds.kek.jp/event/35569.

Summary:
SuperKEKB performance relies on innovative beam optics near the IP (Interaction Point), which exploits the concept of high intensity nano-beams composed of particle bunches colliding according to the crab waist concept. The high beam background related to the high luminosity is anticipated to lead to various concerns.
The goal of the partnership is to build up a comprehensive understanding of the mechanics of the beam pipe elements in the vicinity of the IP, which encompasses the close-by detectors. The topics of the partnership concern the redesign of the beam pipe cooling in the Interaction Region (IR) and the upgrade of the Belle II vertex detector. Both tasks rely on extensive knowledge transfer and require sustained exchanges with the KEK laboratory. They moreover necessitate on-site learning and interventions on the vacuum vessel cooling and on the vertex detector mechanics and services within a particularly constrained topological environment.
The expertise and skills acquired through this partnership can be further applied to future experiments, such as a Higgs factory or ILC in Japan.

French members:
J. Bonis, D. Auguste, E. Kou, F. Le Diberder, M. Winter

Japanese members:
S. Tanaka, K. Nakamura, K. Kanazawa, T. Kohriki, K. Shibata, S. Terui