Meta-materials made of INorganic FIbers for the Next generation of HI energy physics – INFINHI

The aim of the INFINHI project is to propose a new concept of high granularity calorimeter based on the use of inorganic mono-crystalline fibers leading to different functionalities. When assembled, these fibers form which is called in this project a “metacable”. This metacable, is the first element of a larger calorimeter adapted to the next generation of high energy physics experiments. The project is dedicated to validate this concept.
The principle is based on the use of the micro pulling down technique to grow inorganic fibers of the garnet family (such as LuAG). These garnet compositions insure a good stopping power. When doped with cerium ions, these materials give rise to scintillating properties well adapted to this detector type (high scintillation yield, fast decay time). When undoped, only Cherenkov effect is expected. These two kinds of fibers will lead to the different components determination of the shower genereted during intetactions with high energy particles. This concept allows combining various functionalities within a same homogeneous block detector.
Garnet family selection as well as the choice of the crystal growth micro pulling down technology were performed in order to select a scalable process. This particular point is of prior importance in the field of detectors for high energy colliders.
After selecting the exact fiber composition, the optimization process will be done in order to reach the performances required by the end user: CERN which is a partner of this project.
In the frame of the optimization process, the project proposes a careful analysis of the various chemical - physics parameters which are directly connected to the optical quality as well as to the scintillating performances. That will be studied in close connexion with the growth conditions. The detailed analysis of the scintillation process, also necessary for the clear understanding of the overall properties, is an important part of the INFINHI project. In this frame, detailed time resolved spectroscopy under VUV and electronic excitation combined with numerical simulation will be performed.
The consortium involve a company (FiberCryst) which insures to scale up the growth process while preserving the performances, in order to prevent the large amount of fibers needs for a complete detector. Finally, the concept will be validated in true conditions at CERN.

The project partners have complementary expertises and have several join publications for more than ten years. LPCML (project leader) is a specialist of crystal growth of optical materials as well as in luminescence and scintillation spectroscopy. CELIA is a well-know laboratory in the field of luminescence under femto-second VUV laser excitations. FiberCryst is a company specialized in single crystal fibers production. CERN, international partner is the end user and has the required expertise and equipments for the setting up and validation of such detectors.