# Heavy Ion Laboratory of the University of Warsaw

Post-publication activity

Curator: Krzysztof Rusek

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## Heavy Ion Laboratory of the University of Warsaw

The University of Warsaw has had operating accelerators for nuclear physics research since the construction of its first electrostatic accelerator in 1937 by Professor Andrzej Sołtan. Before constructing this accelerator in Poland he spent one year in France (1927-1928, Maurice de Broglie Laboratory) and also one year in the USA ($$1932-1933$$, Pasadena Radiation Laboratory) collaborating with Professors H.R. Crane and C.C. Lauritsen on the production of neutrons by accelerated deuterons $$(Phys. Rev. 44 (1933) 692)$$.

Figure 2: Prof. Sołtan in front of his home made Cockroft-Walton accelerator

After the Second World War prof. Sołtan initiated the construction of a Van de Graaff accelerator at the Faculty of Physics, University of Warsaw.

In the 1970s visionary members of the Polish nuclear physics society proposed the construction of a national laboratory devoted to the study of heavy-ion interactions by the acceleration of beams of these nuclei produced with a K=160 cyclotron. At the time, almost all nuclear physics research centered around the use of light-ion stable beams $$^{4}$$$$He$$ or lighter). Unfortunately, economic difficulties slowed down but did not stop the pursuit of this goal at the University of Warsaw and in $$1994$$ the first beam, $$^{14}$$$$N$$, was used in an experiment. $$(Nuclear Physics News Vol4, No3, 1994)$$. Since this time the Heavy-Ion Laboratory, University of Warsaw, (HIL) has developed a full suite of instruments for carrying out a wide range of experiments in basic nuclear physics as well as several applied science projects.

The HIL is operated as an international user facility with experimenters from around the world contributing to its research environment. The laboratory contains dormitory rooms for experimenters as part of its services for external users. Experimental beam time is allocated by a Program Advisory Council (PAC) and the science of the laboratory is evaluated by a Laboratory Council. Members of PAC come from throughout Europe.

The Heavy Ion Laboratory is located in the middle of the blossoming Ochota Science Campus, housing new physics and technology transfer buildings as well as those devoted to biology, chemistry, earth science and mathematics. Close by is the Medical University of Warsaw which has led to a partnership with the HIL to develop and operate an adjacent but separate light-ion $$(p,d)$$ cyclotron that will be the center of a research laboratory devoted to the production of short-lived radiopharmaceuticals to be used in medical and biological studies. This Radiopharmaceuticals Production and Research Centre will greatly expand the positron emission tomography (PET) capabilities of the Ochota Science Campus. The production of other medical isotopes like $$^{99m}$$$$Tc$$ using this cyclotron is also forseen. The acknowledged expertise of the technical staff of the HIL was important in the decision to host this new project adjacent to the current laboratory.

Figure 3: The layout of the University of Warsaw Heavy Ion Laboratory with the Radiopharmaceuticals Production and Research Centre addition at the top. The lower right shows the K=160 cyclotron

The $$K=160$$ cyclotron produces external B-Ar beams from an ECR-ion source with a maximum energy of $$10 MeV/amu$$. There are now two ECR ion sources available which will allow the development of additional beams should experimenters request them while at the same time carrying out the normal research program. Soon, the range of the available beams will be expanded up to $$Xe$$. The laboratory is well equipped to meet the needs of both external and in house users in carrying out experiments through its experienced technical staff that have target production knowledge as well as the ability to produce advanced detectors. The major research thrusts currently taking place in the HIL are the understanding of the distribution of fusion barriers, Coulomb excitation of nuclei with $$Z$$~$$40$$ and $$N$$~$$6$$, chiral symmetry in nuclei, the production of trans-lead isomers, scattering and reaction of light heavy-ion beams and targets in inverse kinematics, radiation damage to cells and the development of radiopharmaceuticals for both visualization of cell functions in complex biological systems and the treatment of tumors. Some of these areas of research are described in more detail below with the suite of instruments that allows the measurements to be performed. Also, the extensive outreach and hands-on training that takes place in the HIL is described.

### Structure of medium mass nuclei

Figure 4:

Coulomb excitation (Coulex) is a powerful method to study nuclear structure. The Warsaw Coulex Group was formed by Professor Tomasz Czosnyka in the early $$1990s$$. HIL is capable of performing full-scale Coulex experiments with the use of the EAGLE spectrometer. The EAGLE array is designed as a multi-configuration detector setup that can host up to $$30$$ HPGe detectors coupled to a Si ball, electron conversion spectrometer and Coulex scattering chamber. The experimental data are analyzed by the GOSIA code, developed, maintained and updated by the Warsaw Coulex Group.

Other nuclear structure studies make use of the Doppler Shift Attenuation Method to obtain critical lifetime information. These studies are related to the problem of chirality in nuclei with odd numbers of protons and neutrons. There is a lack of data on the lifetimes of states belonging to the chiral twin bands. The group performing experiments in HIL is closely collaborating with the theorists and is amongst the top research groups in this research area.

### Fusion barrier height distributions and reaction studies with light nuclei

Figure 5:

A series of experiments with $$^{20}$$$$Ne$$ beams scattered off different targets revealed that the distribution of the fusion barrier height depends on the structure of the colliding nuclei and also on the processes induced during the scattering. The experiments are performed by means of the large ICARE scattering chamber (1m in diameter) that was brought to the HIL from IRS Strasbourg. In the chamber a variety of gas and semiconductor telescopes can be mounted. Scattering and reaction studies designed to demonstrate the isotopic difference between isotones are performed. The use of inverse kinematics in these studies allows for both small angle and large angle processes to be determined.

These studies are performed using the Warsaw IGISOL facility. It is designed for using heavy ion reactions to produce and study short lived radioactive isotopes. The device consists of a Scandinavian type mass separator, an ion source of the Ion Guide type, a helium pumping system and the detection setup.

### Detector development

A new technology for producing large area, thin silicon strip detectors was recently developed in HIL. The detectors will be used as components of a novel silicon vertex detector for the identification of super-heavy elements.

### Production of medical isotopes with both the medical cyclotron and the $$K=160$$ machine

Figure 6:

Medical applications of nuclear physics knowledge is the second main area of scientific activity in the HIL. The Radiopharmaceuticals Production and Research Centre equipped with the small proton/deuteron cyclotron will produce radiopharmaceuticals for the Warsaw hospitals and also carry out research to produce new radiopharmaceuticals. Its opening took place during the international conference "Positron Emission Tomography in Research and Diagnostics" organized by the HIL in May $$2012$$. There is also an ongoing project to develop the production of $$technetium-99m$$ using this cyclotron. In collaboration with the Silesian University in Katowice, the Institute of Nuclear Physics of the Polish Academy of Sciences in Cracow and the Institute of Nuclear Chemistry and Technology in Warsaw, a scientific program is being developed to produce alpha-emitting isotopes that can be used in cancer therapy. Recently, the production of the $$^{211}$$$$At$$isotope was demonstrated by using the $$Bi(α,2n)$$ reaction.

### Cell radiation damage studies by heavy-ions

In the experiments performed in the HIL the ovary cells of Chinese hamsters are irradiated by heavy ions of different energies and the effect of high LET irradiation on the survival of the cells is studied. Such studies are providing a useful insight into therapeutic approaches for the treatment of human cancers.

### Extensive outreach and hands-on training of students

While the training of graduate and undergraduate students from both Poland and other European countries through their carrying out experiments in the Heavy Ion Cyclotron Laboratory (HIL) are part of its core mission, the laboratory recently has expanded this role by hosting a hands on two-week winter school with graduate students coming from Bulgaria, Poland, Spain and Turkey. During this two weeks, students work with the research and technical staff to mount and carry out an experiment while also attending lectures on advanced topics in nuclear physics. At the end of the school, the students present a twenty minute talks based on their just acquired data.

Figure 7:

The HIL has a long history of working to increase the number of Polish potential science students through its participating in the annual Festival of Science. In addition, tours of the lab by school children and the general public take place routinely. The now close proximity of the University of Warsaw Physics Department as well as the constant interaction between the nuclear physicists and the research teams from the Medical University of Warsaw, will greatly increase the importance of this laboratory to Polish science.

Contact [1] if you want to propose an experiment or visit the laboratory.