Gesellschaft Fur Schwerionenforschung Research Articles

Creation, evolution, and future challenges of ion beam therapy from a medical physicist's viewpoint (Part 3): Chapter 3. Clinical research, Chapter 4. Future challenges, Chapter 5. Discussion, and Conclusion.

Clinical studies of ion beam therapy have been performed at the Lawrence Berkeley Laboratory (LBL), National Institute of Radiological Sciences (NIRS), Gesellschaft für Schwerionenforschung (GSI), and Deutsches Krebsforschungszentrum (DKFZ), in addition to the development of equipment, biophysical models, and treatment planning systems. Although cancers, including brain tumors and pancreatic cancer, have been treated with the Bevalac's neon-ion beam at the LBL (where the first clinical research was conducted), insufficient results were obtained owing to the limited availability of neon-ion beams and immaturity of related technologies. However, the 184-Inch Cyclotron's helium-ion beam yielded promising results for chordomas and chondrosarcomas at the base of the skull. Using carbon-ion beams, NIRS has conducted clinical trials for the treatment of common cancers for which radiotherapy is indicated. Because better results than X-ray therapy results have been obtained for lung, liver, pancreas, and prostate cancers, as well as pelvic recurrences of rectal cancer, the Japanese government recently approved the use of public medical insurance for carbon-ion radiotherapy, except for lung cancer. GSI obtained better results than LBL for bone and soft tissue tumors, owing to dose enhancement enabled by scanning irradiation. In addition, DKFZ compared treatment results of proton and carbon-ion radiotherapy for these tumors. This article summarizes a series of articles (Parts 1-3) and describes future issues of immune ion beam therapy and linear energy transfer optimization.

Physical characterization of 3He ion beams for radiotherapy and comparison with 4He

There is increasing interest in using helium ions for radiotherapy, complementary to protons and carbon ions. A large number of patients were treated with 4He ions in the US heavy ion therapy project and novel 4He ion treatment programs are under preparation, for instance in Germany and Japan. 3He ions have been proposed as an alternative to 4He ions because the acceleration of 3He is technically less difficult than 4He. In particular, beam contaminations have been pointed out as a potential safety issue for 4He ion beams. This motivated a series of experiments with 3He ion beams at Gesellschaft für Schwerionenforschung (GSI), Darmstadt. Measured 3He Bragg curves and fragmentation data in water are presented in this work. Those experimental data are compared with FLUKA Monte Carlo simulations. The physical characteristics of 3He ion beams are compared to those of 4He, for which a large set of data became available in recent years from the preparation work at the Heidelberger Ionenstrahl-Therapiezentrum (HIT). The dose distributions (spread out Bragg peaks, lateral profiles) that can be achieved with 3He ions are found to be competitive to 4He dose distributions. The effect of beam contaminations on 4He depth dose distribution is also addressed. It is concluded that 3He ions can be a viable alternative to 4He, especially for future compact therapy accelerator designs and upgrades of existing ion therapy facilities.

Development and Construction of Track and Identification Systems for Experiments Aimed at Studying Extreme Properties of Nuclear Matter in Nucleus–Nucleus Collisions

Investigation of properties of nuclear matter at extremely high temperature and/or extremely high baryon densities under laboratory conditions is one of the fundamental lines of research in high-energy physics. Throughout the past decades, such investigations have been performed in collisions of ultrarelativistic heavy ions in several experiments at modern accelerator complexes, including the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL, USA) and the Large Hadron Collider (LHC) at CERN (Switzerland). In the near future, it is also planned to launch investigations of this kind at the FAIR (Facility for Antiproton and Ion Research at Gesellschaft fur Schwerionenforschung (GSI), Darmstadt, Germany) and NICA (Nuclotron-based Ion Collider fAcility at Joint Institute for Nuclear Research (JINR), Dubna, Russia) accelerators. In order to implement such investigations, it is necessary to create sophisticated detector systems that are able to record events featuring high-multiplicity product particles and to measure reliably their properties. The present article gives a brief survey of all detector systems that have already been created and are being developed at Laboratory of Relativistic Nuclear Physics at Petersburg Nuclear Physics Institute (National Research Center Kurchatov Institute) for the PHENIX (BNL, USA), ALICE (CERN, Switzerland), and CBM (GSI, Germany) experiments aimed at studying nuclear matter under extreme conditions.

Stripping of relativistic uranium-ion beams by foils

The dynamics of relativistic uranium-ion beams stripped by foils from Be to Au is investigated in the 100–500 MeV/u energy range. Calculations of the charge-state distributions of uranium fractions as a function of foil thickness are performed using the BREIT code, based on the analytical solution of the balance rate equations for the ion charge-state fractions. Relativistic electron-loss and electron-capture cross sections, required for BREIT as input data, are calculated for interactions of Uq+ ions, q = 65–92, colliding with Be, C, Al, Ti, Cu, Mo, W, and Au atoms. The beam energy losses are found to be rather small, less than 20%, and are not accounted for in calculations. Calculated charge-state distributions are compared with available experimental data, obtained at the GSI (Gesellschaft für Schwerionenforschung) and BEVALAC (Bevatron Linear Accelerator) facilities, and with calculations by the GLOBAL code created at GSI.The optimal conditions are predicted for production of bare, H-like, He-like and Li-like uranium ions with the largest probabilities. Dependencies of the equilibrium thicknesses for uranium charge-state fractions on the initial charge of incident ions are investigated.

Charge-state distributions of relativistic gold-ion beams stripped by foils

The dynamics of charge-state fractions of relativistic gold-ion beams stripped by foils from Be to Au is investigated in the 100 MeV/u to 10 GeV/u energy range. Calculations of the fractions as a function of foil thickness are performed using the recently developed breit code based on the analytical solution of the balance rate equations for the ion charge-state fractions. Relativistic electron-loss and electron-capture cross sections, required for breit as input data, are calculated. The influence of the beam energy loss on the charge-state fractions is found to be small: less than 15%. Calculated charge-state distributions are compared with available experimental data, obtained at the GSI (Gesellschaft f\ur Schwerionenforschung), RHIC (Relativistic Heavy Ion Collider), and BEVALAC (Bevatron Linear Accelerator) facilities, and calculations of the global code created at GSI. The present calculations of the charge-state distributions allow one to find the optimal conditions for the maximal yield of H-like, He-like, and bare gold ions at energies considered.

Development of nuclear chemistry at Mainz and Darmstadt

Abstract This review describes some key accomplishments of Günter Herrmann such as the establishment of the TRIGA Mark II research reactor at Mainz University, the identification of a large number of very neutron-rich fission products by fast, automated chemical separations, the study of their nuclear structure by spectroscopy with modern detection techniques, and the measurement of fission yields. After getting the nuclear chemistry group, the target laboratory, and the mass separator group established at the Gesellschaft für Schwerionenforschung (GSI) in Darmstadt, a number of large international collaborations were organized exploring the mechanism of deeply inelastic multi-nucleon transfer reactions in collisions of Xe and U ions with U targets, Ca and U ions with Cm targets, and the search for superheavy elements with chemical separations after these bombardments. After the Chernobyl accident, together with members of the Institute of Physics, a powerful laser technique, the resonance ionization mass spectometry (RIMS) was established for the ultra-trace detection of actinides and long-lived fission products in environmental samples. RIMS was also applied to determine with high precision the first ionization potentials of actinides all the way up to einsteinium. In the late 1980ies, high interest arose in results obtained in fusion-evaporation reactions between light projectiles and heavy actinide targets investigating the chemical properties of transactinide elements (Z≥104). Remarkable was the observation, that their chemical properties deviated from those of their lighter homologs in the Periodic Table because their valence electrons are increasingly influenced by relativistic effects. These chemical results could be reproduced with relativistic quantum-chemical calculations. The present review is selecting and describing examples for fast chemical separations that were successful at the TRIGA Mainz and heavy-ion reaction studies at GSI Darmstadt.

Interaction of annular-focused laser beams with solid targets

AbstractThe two-temperature, 2D hydrodynamic code Hydro–ELectro–IOnization–2–Dimensional (HELIO2D), which takes into account self-consistently the laser energy absorption in a target, ionization, heating, and expansion of the created plasma is elaborated. The wide-range two-temperature equation of state is developed and used to model the metal target dynamics from room temperature to the conditions of weakly coupled plasma. The simulation results are compared and demonstrated a good agreement with experimental data on the Mg target being heated by laser pulses of the nanosecond high-energy laser for heavy ion experiments (NHELIX) at Gesellschaft fur Schwerionenforschung. The importance of using realistic models of matter properties is demonstrated.

Investigation of the structure of light exotic nuclei by proton elastic scattering in inverse kinematics

In order to study the spatial structure of exotic nuclei, it was proposed at the Petersburg Nuclear Physics Institute (PNPI) to measure the differential cross section for small-angle proton elastic scattering in inverse kinematics. Several experiments in beams of 0.7-GeV/nucleon exotic nuclei were performed at the heavy-ion accelerator facility of GSI (Gesellschaft fur Schwerionenforschung, Darmstadt, Germany) by using the IKAR ionization spectrometer developed at PNPI. The IKAR ionization chamber filled with hydrogen at a pressure of 10 bar served simultaneously as a target and as a recoil-proton detector, which measured the recoil-proton energy. The beam-particle scattering angle was also measured. The results obtained for the cross sections in question were analyzed on the basis of the Glauber-Sitenko theory using phenomenological nuclear-density distributions with two free parameters. Nuclear-matter distributions and root-mean-square radii were found for the nuclei under investigation. The size of the halo in the 6He, 8He, 11Li, and 14Be nuclei was determined among other things. Information about neutron distributions in nuclei was deduced by combining the data obtained here with the known values of the radii of proton distributions. A sizable neutron skin was revealed in the 8Li, 9Li, and 12Be nuclei.

β-decay studies of neutron-rich Tl, Pb, and Bi isotopes

The fragmentation of relativistic uranium projectiles has been exploited at the Gesellschaft fur Schwerionenforschung laboratory to investigate the β decay of neutron-rich nuclei just beyond 208Pb. This paper reports on β-delayed γ decays of 211-213Tl, 215Pb, and 215-219Bi de-exciting states in the daughters 211-213Pb, 215Bi, and 215-219Po. The resulting partial level schemes, proposed with the help of systematics and shell-model calculations, are presented. The role of allowed Gamow-Teller and first-forbidden β transitions in this mass region is discussed. © 2014 American Physical Society.

Total and Partial Fragmentation Cross-Section of 500 MeV/nucleon Carbon Ions on Different Target Materials

By using an experimental setup based on thin and thick double-sided microstrip silicon detectors, it has been possible to identify the fragmentation products due to the interaction of very high energy primary ions on different targets. Here we report total and partial cross-sections measured at GSI (Gesellschaft fur Schwerionenforschung), Darmstadt, for 500 MeV/n energy $^{12}C$ beam incident on water (in flasks), polyethylene, lucite, silicon carbide, graphite, aluminium, copper, iron, tin, tantalum and lead targets. The results are compared to the predictions of GEANT4 (v4.9.4) and FLUKA (v11.2) Monte Carlo simulation programs.

Design and Analysis of the Thermal Shield of the Prototype Superconducting Dipole Magnet for GSI

For the prototype superconducting dipole magnet of the collector ring for Gesellschaft fur Schwerionenforschung, Germany, the thermal radiation from outside would be shielded by the thermal shield (TS). Considering thermal and mechanical properties, the detailed structure of the TS is discussed. For example, the overview and the design concept of the TS scheme are presented. The layout of the cooling pipe system on the outer and inner surfaces has been considered in terms of the forced-flow liquid nitrogen. Moreover, the multilayer insulation made of aluminized Mylar with woven Dacron netting between the layers is applied to the TS's surface for shielding the thermal radiation. In addition, the eddy-current and mechanical analyses are performed. The cryogenic performance testing indicated that the TS can meet the requirements.

Research and development of a Mini-RICH detector with a gas radiator as a first step towards a CBM-RICH prototype

The Compressed Baryonic Matter (CBM) Experiment is planned to be installed at a future accelerator facility, SIS 100/300 of FAIR (Facility for Antiproton and Ion Research), GSI (Gesellschaft fur SchwerIonenforschung) to study nuclear matter under extreme conditions with a high baryon density. A Ring Imaging Cherenkov (RICH) detector is now being developed for electron identification at pe < 8 GeV/c, well separated from pions. In order to optimize the physics performance of the CBM-RICH detector and to investigate different gas radiators, we developed a mini-RICH detector with a gas system as a first prototype and tested it with the pe ≃ 60 MeV/c electron beam at the Pohang Accelerator Laboratory (PAL).

Mechanism of “GSI oscillations” in electron capture by highly charged hydrogen-like atomic ions

We suggest a qualitative explanation of oscillations in electron capture decays of hydrogen-like 140Pr and 142Pm ions observed recently in an ion experimental storage ring (ESR) of Gesellschaft fur Schwerionenforschung (GSI) mbH, Darmstadt, Germany. This explanation is based on the electron multiphoton Rabi oscillations between two Zeeman states of the hyperfine ground level with the total angular momentum F = 1/2. The Zeeman splitting is produced by a constant magnetic field in the ESR. Transitions between these states are produced by the second, sufficiently strong alternating magnetic field that approximates realistic fields in the GSI ESR. The Zeeman splitting amounts to only about 10−5 eV. This allows explaining the observed quantum beats with the period 7 s.

Acute toxicity of combined photon IMRT and carbon ion boost for intermediate-risk prostate cancer – Acute toxicity of 12C for PC

Background. Carbon ion (12C) therapy in the treatment of prostate cancer (PC) might result in an improved outcome as compared to low linear energy transfer irradiation techniques. In this study, we present the first interim report of acute side effects of the first intermediate-risk PC patients treated at the GSI (Gesellschaft für Schwerionenforschung) and the University of Heidelberg in an ongoing clinical phase I/II trial using combined photon intensity modulated radiation therapy (IMRT) and 12C carbon ion boost. Material and methods. Fourteen patients (planned accrual: 31 pts) have been treated within this trial so far. IMRT is prescribed to the median PTV at a dose of 30 × 2 Gy; 12C boost is applied to the prostate (GTV) at a dose of 6 × 3 GyE using raster scan technique. Safety margins added to the clinical target volume were determined individually for each patient based on five independent planning computed tomography (CT)-scans. Acute gastrointestinal (GI) and genitourinary (GU) toxicity was assessed and documented according to the CTCAE Version 3.0. Results. Radiotherapy was very well tolerated without any grade 3 or higher toxicity. Acute anal bleeding grade 2 was observed in 2/14 patients. Rectal tenesmus grade 1 was reported by three other patients. No further GI symptoms have been observed. Most common acute symptoms during radiotherapy were nocturia and dysuria CTC grade 1 and 2 (12/14). There was no severe acute GU toxicity. Conclusion. The combination of photon IMRT and carbon ion boost is feasible in patients with intermediate-risk PC. So far, the treatment has been well tolerated. Acute toxicity rates were in good accordance with data reported for high dose IMRT alone.

Analysis of the reliability of the local effect model for the use in carbon ion treatment planning systems

In radiotherapy with carbon ions, biological effects of treatments have to be predicted. For this purpose, one of the most used models is the local effect model (LEM) developed at the Gesellschaft für Schwerionenforschung (GSI), Germany. At the Istituto Nazionale di Fisica Nucleare, Italy, the reliability of the last published version of LEM (LEM III) in reproducing radiobiological data has been checked under both monoenergetic and spread-out Bragg peak (SOBP) carbon-ion irradiation. The reproduction of the monoenergetic measurements with the LEM was rather successful for some cell lines, while it failed for the less-radioresistant ones. The SOBP experimental trend was predicted by the LEM, but a large shift between model curves and measured points was observed.

Heidelberg Ion Therapy Center (HIT): Initial clinical experience in the first 80 patients

The Heidelberg Ion Therapy Center (HIT) started clinical operation in November 2009. In this report we present the first 80 patients treated with proton and carbon ion radiotherapy and describe patient selection, treatment planning and daily treatment for different indications. Patients and methods. Between November 15, 2009 and April 15, 2010, 80 patients were treated at the Heidelberg Ion Therapy Center (HIT) with carbon ion and proton radiotherapy. Main treated indications consisted of skull base chordoma (n = 9) and chondrosarcoma (n = 18), malignant salivary gland tumors (n=29), chordomas of the sacrum (n = 5), low grade glioma (n=3), primary and recurrent malignant astrocytoma and glioblastoma (n=7) and well as osteosarcoma (n = 3). Of these patients, four pediatric patients aged under 18 years were treated. Results. All patients were treated using the intensity-modulated rasterscanning technique. Seventy six patients were treated with carbon ions (95%), and four patients were treated with protons. In all patients x-ray imaging was performed prior to each fraction. Treatment concepts were based on the initial experiences with carbon ion therapy at the Gesellschaft für Schwerionenforschung (GSI) including carbon-only treatments and carbon-boost treatments with photon-IMRT. The average time per fraction in the treatment room per patient was 29 minutes; for irradiation only, the mean time including all patients was 16 minutes. Position verification was performed prior to every treatment fraction with orthogonal x-ray imaging. Conclusion. Particle therapy could be included successfully into the clinical routine at the Department of Radiation Oncology in Heidelberg. Numerous clinical trials will subsequently be initiated to precisely define the role of proton and carbon ion radiotherapy in radiation oncology.

SUPERHEAVY RESEARCH AT RIKEN

At RIKEN (The Institute of Physical and Chemical Research) in Japan, we have performed experiments to study the productions and decays of the heaviest elements produced by one neutron emission channels of 208 Pb and 209 Bi based heavy-ion induced fusion reactions. A gas-filled type recoil separator has been used for collecting evaporation residues of the reactions separating them from high intensity beam particles. The reactions studied were 208 Pb (58 Fe , n )265 Hs , 208 Pb (64 Ni , n ) 271 Ds , 209 Bi (64 Ni , n ) 272 Rg , 208 Pb (70 Zn , n ) 277112, and 209 Bi (70 Zn , n ) 278113. In studies of the first four reactions we have provided the independent confirmations of the productions and their decays of the isotopes, 265 Hs , 271 Ds , 272 Rg , and 277112, as well as the decay properties of their decay daughters, previously studied by Hofmann et al., a group of Gesellschaft für Schwerionenforschung (GSI), Germany. In the last reaction, we observed two decay chains originated from the isotope 278113, assigned firstly by generic correlation of the alpha decay chains connected into the previously known decay of 266 Bh and 262 Db via previously unknown alpha decays of 278113, 274 Rg and 270 Mt .

In-beam PET monitoring of mono-energetic 16O and 12C beams: experiments and FLUKA simulations for homogeneous targets

16O and 12C ion beams will be used—besides lighter ions—for cancer treatment at the Heidelberg Ion Therapy Center (HIT), Germany. It is planned to monitor the treatment by means of in-beam positron emission tomography (PET) as it is done for therapy with 12C beams at the experimental facility at the Gesellschaft für Schwerionenforschung (GSI), Darmstadt, Germany. To enable PET also for 16O beams, experimental data of the β+-activity created by these beams are needed. Therefore, in-beam PET measurements of the activity created by 16O beams of various energies on targets of PMMA, water and graphite were performed at GSI for the first time. Additionally reference measurements of 12C beams on the same target materials were done. The results of the measurements are presented. The deduction of clinically relevant results from in-beam PET data requires reliable simulations of the β+-activity production, which is done presently by a dedicated code limited to 12C beams. Because this code is not extendable to other ions in an easy way, a new code, capable of simulating the production of the β+-activity by all ions of interest, is needed. Our choice is the general purpose Monte Carlo code FLUKA which was used to simulate the ion transport, the β+-active isotope production, the decay, the positron annihilation and the transport of the annihilation photons. The detector response was simulated with an established software that gives the output in the same list-mode data format as in the experiment. This allows us to use the same software to reconstruct measured and simulated data, which makes comparisons easier and more reliable. The calculated activity distribution shows general good agreement with the measurements.

Discovery of the element with atomic number 112 (IUPAC Technical Report)

The IUPAC/IUPAP Joint Working Party (JWP) on the priority of claims to the discovery of new elements has reviewed the relevant literature pertaining to several claims. In accordance with the criteria for the discovery of elements previously established by the 1992 IUPAC/IUPAP Transfermium Working Group (TWG), and reiterated by the 1999 and 2003 IUPAC/IUPAP JWPs, it was determined that the 1996 and 2002 claims by the Hofmann et al. research collaborations for the discovery of the element with atomic number 112 at Gesellschaft für Schwerionenforschung (GSI) share in the fulfillment of those criteria. A synopsis of Z = 112 experiments and related efforts is presented. A subsequent report will address identification of higher-Z elements including those of odd atomic number.

Review of high energy density physics: The HEDgeHOB Collaboration

High Energy Density Physics (HEDP) is one of the most important and interesting areas of science that spans over numerous branches of basic and applied physics. In this paper, we present an overview of different experimental techniques that have been used to study this field over the past decades. We also introduce a recently proposed novel technique to study HEDP that involves isochoric and uniform heating of extended targets using intense particle beams. The Gesellschaft für Schwerionenforschung (GSI), Darmstadt, is a leading laboratory worldwide that is well known for its unique accelerator facilities. The construction of a new accelerator complex named FAIR (Facility for Antiprotons and Ion Research) will substantially increase the accelerator capabilities of GSI, which will make it possible to employ this new technique to study HEDP. In this paper we highlight some of the salient features of this proposed new method. We also note that in order to organize the construction of experimental facilities at FAIR and later to carry out experiments on HEDP, an international collaboration, named, HEDgeHOB (High Energy Density Matter generated by Heavy IOn Beams), has been organized. The work presented in this paper has been done within the framework of the HEDgeHOB Collaboration.