Personal profile

Research interests


My main field of study is radiation physics. This includes two complementary lines of activity: (1) the development of new detection concepts and techniques for experiments in nuclear, particle and astroparticle physics, as well as for practical applications, e.g., in the nuclear industry and aviation security; (2) the development of new concepts in radiation therapy. My two main projects are the NEXT experiment (in the framework of the international NEXT Collaboration), searching for an ultra-rare mode of radioactive decay, and Diffusing alpha-emitters Radiation Therapy (DaRT) – a new method for treating cancer with alpha particles – developed together with Alpha Tau Medical Ltd. Additional projects are the development of a new generation of high-granularity ultrafast-timing detectors for fast neutrons and gamma rays, in collaboration with NRCN, the development of low-background nuclear spectroscopy techniques with Soreq NRC, the development of new detection concepts for noble-liquid detectors pursued jointly with colleagues at the Weizmann Institute of Science (WIS), R&D on gas-avalanche detectors with colleagues at WIS, and R&D on radiotracer-based atomic diffusion studies with colleagues at NRCN and the Technion.


The NEXT experiment is one of the three leading collaborations in Europe searching for neutrinoless double beta decay. A detection of this hypothetical radioactive process (whose half-life is >1026 yr) will answer a fundamental question in particle physics‒‒whether the neutrino is its own antiparticle--with profound implications to our understanding of the universe. It is therefore considered one of the primary goals of experimental nuclear and particle physics today. The NEXT collaboration includes about 20 research institutes from Europe and the US. Until recently BGU was the only Israeli institute to participate in an experiment searching for neutrinoless double beta decay; this changed when Dr. Itay Shomroni from the Hebrew University joined NEXT to collaborate with the BGU group.

BGU group members take part in collaboration-wide activities, related to operation of the experiment, data taking and analysis in both the main detectors (NEXT-White, NEXT-100) and smaller prototype (NEXT-DEMO), and R&D of new experimental techniques for the next stages of the program.

The BGU group has developed a new method of event reconstruction and analysis, using Richardson-Lucy deconvolution, which leads to a dramatic reduction of background (by a factor of 5). This work, published in the Journal of High Energy Physics, had a major impact on the experiment and has completely transformed its track reconstruction methodology. After its introduction and demonstration on calibration data, the new method served as the basis for the most important physics analyses of NEXT-White − a model-independent measurement of the two-neutrino double beta decay of 136Xe, and a demonstration of the NEXT technology’s ability to set a limit on the neutrinoless double beta decay half-life. In addition, BGU leads the investigation of cryogenic operation of NEXT detector prototypes, which is considered a promising approach for future stages of the experiment. In this respect, we have recently completed a careful experimental study at BGU (“AXOLOTEL-0”), showing that the attainable energy resolution in pure xenon remains the same – and close to the statistical limit – when cooling the gas down to 175 K at 1-2 bar. An additional observation was that the scintillation light yield increases at low temperature by up to ~20%. The study will now be expanded to high pressure (up to 10 bar) and will investigate the use of xenon-helium gas mixtures, which can offer a major improvement in 3D track imaging without compromising the energy resolution. The experimental setup for these extended studies (“AXOLOTEL-1”) is under commissioning. The BGU group is further responsible for the development of novel ion sources for studies on barium tagging – a technique that will allow the identification of an individual barium-136 ion resulting from a neutrinoless double beta decay event – potentially leading to a background-free detector. This is a main effort of the collaboration, which recently resulted in a 9.3M€ ERC Synergy grant, in which BGU is a beneficiary. In addition, BGU develops a new concept for the use of 224Ra++ as a radioactive surrogate for Ba++, opening the door for precision-level tests of the barium tagging concept in high-pressure Xe detector prototypes. This latter idea was awarded an ISF grant in 2021. Lastly, the BGU group plays a leading role in the development of light readout by wavelength-shifting fibers in future stages of NEXT, a project which was recently awarded a new Pazy research grant.

The NEXT BGU group presently includes one postdoc (Dr. Gonzalo Martínez-Lema), three PhD students (Yair Ifergan, Adam Redwine, and Guy Heger, who also works on DaRT), two MSc student (Amir Ben Haim and Shlomi Stampfer), two consultants (Dr. Sergei Shchemelinin and Dr. David Vartsky) and a collaborator from NRCN (Dr. Itamar Israeli). Previous group members are Dr. Ander Simón Estévez (now a Marie Curie postoctoral fellow at the University of Chicago), and Dr. Ryan Felkai (now a postdoc at the Weizmann Institute). Funding is from the two Pazy grants, the ERC grant and the recent ISF grant.  

Diffusing alpha-emitters Radiation Therapy (DaRT)

My second main project is the development of a revolutionary new cancer treatment – Diffusing alpha-emitters Radiation Therapy (DaRT) – where, for the first time, solid tumors are treated by implantable sources releasing alpha emitting atoms from their surface. These spread over several mm around each source, leading to tumor ablation with essentially no radiation damage to surrounding healthy tissue. This project is carried out in close collaboration with the group of Dr. Tomer Cooks (from BGU Department of Immunology, Microbiology & Genetics) and Alpha TAU Medical Ltd., and has already reached clinical trials on human patients with remarkable results. My responsibility here is to develop the physical model that describes the migration of alpha emitting atoms inside the treated tumor, as a basis for treatment planning, as well as to investigate new paths for further improving the efficacy of the method. DaRT BGU group presently includes one postdoc (Dr. Arindam Roy), four PhD students (Yevgeniya Korotinsky, Guy Heger, Noam Weizman and Lior Epstein - the latter from Soreq NRC and under joint supervision with colleagues from Tel Aviv University), and two MSc students (Yadin Cohen and Ariel Romi). The group previously included Dr. Mirta Dumančić, now a postdoc at McGill University, Montreal, Canada). Funding is (mostly) from Alpha TAU Medical, through a contract with BG Negev.

Fast-neutron and gamma-ray imaging detectors

A third project in my group concerns the development of highly granular scintillation detectors for fast neutrons and gamma rays, with sub-ns timing resolution. The research is funded by a grant from the Ministry of Science and Technology and is carried out at BGU, in collaboration with NRCN. We develop detector prototypes for two application: (1) Fast-Neutron Multiplicity Counting – a technique for characterizing the fissile content of nuclear waste by the coincident detection of bursts of neutrons and gammas emitted in fission events; (2) Fast-Neutron Resonance Radiography (FNRR) –a Time-of-Flight  fast-neutron spectroscopic radiography method that exploits characteristic variations of the total cross section for neutron energies from sub-MeV to 10 MeV to determine the identity and density distribution of specific elements within an inspected object, via the dependence of the transmission on the neutron energy. Thus, FNRR not only provides radiographic information about the internal structure of the investigated object, but also allows identifying its elemental composition. It can therefore be highly attractive for applications such as aviation security, nuclear waste characterization, and oil exploration. The method requires the use of a pulsed neutron beam which provides a continuous spectrum of MeV neutrons, and a neutron imaging system with ns-scale time resolution. The FNMC and FNRR projects involve one postdoc (Dr. Arindam Roy), one PhD student (Yaacov Yehuda Zada from NRCN), two NRCN MSc students (David Michaeli and Michael Faziev), two collaborators from NRCN (Dr. Erez Cohen and Dr. Arie Beck), one consultant (Dr. David Vartsky), and one part-time technician (Hanania Ettedgui).

Cryogenic noble-liquid detectors

An additional project in my group is the development of new detection concepts for future noble liquid detectors (using liquid xenon and liquid argon), with potential applications in dark matter searches and neutrino physics experiments. This activity is carried out in collaboration with Prof. Amos Breskin and Prof. Shikma Bressler at the Weizmann Institute of Science. It includes two lines of research: (1) the development of cryogenic gaseous detectors for light and charge detection; (2) the development of bubble-assisted liquid hole multipliers. These projects involve the activities of two postdocs  – Dr. Arindam Roy and Dr. Gonzalo Martínez-Lema - and are of potential relevance to the future DARWIN experiment.

Low-background nuclear spectroscopy

This line of activity involved a collaboration with Dr. Ofer Aviv and Dr. Michal Brandis from Soreq NRC, on the development of a low-background nuclear spectroscopy system, combining a liquid scintillation detector and high-purity germanium detector operating in coincidence. The project was carried out by Sagi Nissim (NRCN, now a PhD student of Prof. Erez Gilad at BGU Nuclear Engineering) as his MSc.

Gaseous detectors

I have recently resumed my prior studies on gas-avalanche detectors for particle physics experiments with Prof. Shikma Bressler at WIS. We have a joint PhD student (Darina Zavazieva, studying at BGU), working on a new type of sampling elements for hadronic calorimetry.

Other projects

As part of a collaboration with Dr. Ofer Beeri (NRCN) and Prof. Yaron Amouyal (Technion), I am involved in developing a method for measuring atomic diffusion in materials using radioactive tracers. This is the MSc project of Zeev Akerman (NRCN).

Expertise related to UN Sustainable Development Goals

In 2015, UN member states agreed to 17 global Sustainable Development Goals (SDGs) to end poverty, protect the planet and ensure prosperity for all. This person’s work contributes towards the following SDG(s):

  • SDG 3 - Good Health and Well-being
  • SDG 7 - Affordable and Clean Energy


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