FAIR - Facility for Antiproton and Ion Research

High-Resolution In-Flight Spectrosopy/Decay Spectroscopy (HiSpec/DeSpec) experiments aim for high-resolution spectroscopy after decay of an unstable atomic nucleus, or of excited states in exotic nuclei after nuclear excitation. The experiments are addressing key issues in nuclear structure, reactions and nuclear astrophysics at the limits of nuclear existence. The basic tool is a high resolution γ-ray spectroscopy array, complemented by various ancillary detector systems to discriminate the isomeric γ rays of the nuclei of interest from the unwanted background radiation (the expected total rate of the desired signal is around 0.001-1 decays per second, with background rate of around 100-500 per second per detector). A key veto system based on BGO (bismuth germanate) detectors was optimized by our group, including the optical transport simulations, development of readout electronics and photodiode placement optimization. A second generation of readout is currently underway, including automated temperature compensation and diagnostic subsystems and is to be tested in 2022. We have been actively involved in the HiSpec/DeSpec Phase 0 experiments. We are also involved in the instrumental build-up of HISPEC-10, aimed at investigation of short lived or chemically inert nuclei.

DESPEC set-up for FAIR phase 0

The central instrument of NUSTAR collaboration is Super-FRS. The uniqueness of FAIR accelerator system is in its feature that it is the only one in the world that will be able to produce extremely intense, high energy beams of the heaviest naturally occurring element, uranium. Exotic nuclei will be produced either by its fragmentation or fission. The reaction products will be separated from the primary beams using SFRS. SFRS along with its beamline detectors will enable event-by-event identification of exotic nuclei. High acceptance of SFRS, as well as high energy/intensity primary beams and usage of the state of the art detector systems will enable the sensitivity of experiments necessary to reach the limits of nuclear existence for many isotopes.

The main instrument of the NUSTAR collaboration is the Fragment Separator (FRS), to be superseded by a more capable SFRS, designed to be the only magnetic separator in the world, able to separate intense beam of ions of any element, up to uranium. Mass slectivity of the (S)FRS is further drastically improved with a TOF mass separator – for the latter, we have developed an electrostatic lens stabilization monitor and shortly after the installation achieved the world record in mass resolution of TOF spectrometers. We have participated in FAIR phase 0 SFRS experiments.

Slovenian team is involved in the development of the experimental equipment required for accurate measurements of extremely high voltages. We are also involved in the development of the simulations toolkit used to predict the behaviour of the FRS-IC that allows experiment operators to have a better and more in-depth understanding of the system.

FRS-IC scheme

The R3B experiment at FAIR will be the only facility worldwide providing the capability for kinematically complete measurements of reactions with relativistic heavy-ion beams up to around 1 AGeV, which provides sufficiently high resolution to enable a comprehensive experimental investigation of fundamental questions relating to nuclear-structure, astrophysics, and properties of bulk (isospin-asymmetric) nuclear matter. The CALIFA (CALorimeter for the In Flight detection of γ-rays and light charged pArticles) calorimeter that will surround the reaction target, is one of the key detectors of the R3B facility, accordingly it is optimised for the requirements of the ambitious physics program proposed by the R3B collaboration. For the R3B collaboration, we have assembled and characterised 60 detector elements for the CALIFA scintillation calorimeter.

A series of seminars on FAIR is on programme tentativelly in the first half of 2022. The initiative aims to disseminate among Slovenian scientists, engineers, and students the knowledge about the FAIR accelerator centre in construction at Darmstadt (Germany), one of the world's largest centres of this type. The seminars will discuss the main research topics of FAIR (NUSTAR, CBM, PANDA, APPA), the status of the project, and above all - the participation of Slovenian research groups in this project. The seminars will be organized in a hybrid form - both live and using one or the other video conferencing method. Recorded seminars will be available in this folder.

The first seminar was held as JSI Colloquia on Wednesday, March 16th, 2022, at 11:15AM. Prof dr Paolo Giubellino and Mr Joerg Blaurock (both GSI/FAIR, Darmstadt, Germany) had a lecture titled "The Universe in the Lab". The lecture is available below:

The second seminar "Research Opportunities and Perspectives of NUSTAR at FAIR" was held by Dr Jürgen Gerl, FAIR/GSI, Darmstadt, Germany on Tuesday, March 29th at 10:00AM in the big lecture hall at JSI, Jamova 39, 1000 Ljubljana. NUSTAR, standing for Nuclear Structure, Astrophysics and Reactions, is the largest nuclear physics collaboration in the world. It has been initiated as one of the four research pillars of the mega-science project FAIR, under construction at GSI. NUSTAR relies primarily on the availability of exotic rare isotope beams produced by fragmentation reactions and fission of relativistic heavy ions. Construction of the FAIR buildings and production of the machine and experiment components is proceeding well. Until the FAIR facility will become operational for first experiments in 2025, a Phase-0 experimental program is being pursued at GSI employing already available experimental set-ups.

The presentation provided an overview of current research opportunities as well as the perspectives for NUSTAR physics at GSI/FAIR.

The lecture took place in English, it is now available below:

The third seminar of the FAIR series will be held on Monday, May 23rd, 2022 at 10AM,

Prof Dr Marco Durante will talk about the recent advances in particle therapy. The lecture will be accessible live via ZOOM link here.

Radiotherapy is one of the most common and effective therapy for cancer. Generally, patients are treated with X-rays produced at electron accelerators. The use of high-energy charged particles was proposed several years ago, both for their physical and radiobiological advantages compared to X-rays. Particle therapy is now becoming an emerging technique in radiotherapy. Protons and carbon ions have been used for treating many different solid cancers, and several new centers with large accelerators are under constructions. However, there is currently an open debate on the cost/benefit ratio of this technique.

The Biophysics group at GSI had in the past years an intense activity in the 12C-ion therapy pilot project. The treatment of tumours at the base of the skull and brain was extremely successfully, using the technique of raster scanning (see figure). The therapy project paved the way to ion therapy in Europe, leading to the construction and planning of several clinical accelerator facilities. However, several research issues are still open in this field, for instance: predicting RBE of different particles in the tumours and in the normal tissue; treatment of moving targets; impact of genetic background on sensitivity; effects on angiogenesis and metastatic potential; fractionation; hypoxia; combined treatments with chemo- and immunotherapy.

This talk identifies the open research questions and shows some recent data recently obtained in some of these fields.