Experimental and Theoretical Study of Energy Deposition and Residual Activation Induced by Uranium Ions to Model the Beam Loss Hazards in the GSI Future Facility GSI-INTAS Project Reference Number May 2004 – April 2006 Budget 90 k€

Motivation Intensities up to of U ions and 2.5·10 13 of protons are foreseen in the FAIR accelerators. Such high intensities will unavoidably be accompanied with high level of beam losses. Although the proton beam loss hazards are well understood in the accelerator community there are many unknowns in how the lost heavy ions affect the accelerator equipment and surroundings. The problems related to beam loss induced hazards can roughly be classified into three categories: 1.Residual activation. 2.Damage to the equipment. 3.Shielding.

Residual Activation It is generally recognized (although arguable) that the ‚hands-on‘ maintenance is the main beam-loss limiting factor in the proton accelerators: W=1 w/m allowed losses in a 1 GeV proton machine. There is no limiting values for heavy-ion beam losses recognized by the accelerator community so far.

Damage to the Equipment Superconducting magnets are the equipment most sensitive to the radiation damage. What is the overall heat load to the cryogenic system induced by lost particles? What beam loss level is safe against quenching? What is the tolerable beam loss level to have “reasonable” lifetime of materials with low radiation hardness like organic materials, superconducting wires and semiconducting diodes?

Shielding There are spots in the accelerators and the transfer channels with planned high beam loss level, like injection-extraction regions, aperture limiting devices, collimators, targets and beam dumps. The SHIELD code has been proven to be a reliable tool to simulate neutron yields for lost ions as high as Uranium with the kinteic energy of 1 GeV/u. It works reliably with U ions also at the top energy 37 GeV/u foreseen in the FAIR Facilities.

Structure of the Project Project Teams: INTAS (Western) GSI Darmstadt, E.Mustafin. STU Bratislava, M.Pavlovic. NIS (Eastern) ITEP Moscow, A.Golubev. VNIIEF Sarov, V.Vatulin. INR RAS Moscow, N.Sobolevskiy. Project Tasks: 1.Energy deposition measurements, A.Golubev. 2.Activation measurements, A.Fertman. 3.Modeling of the experimental set-up with the help of the SHIELD code and validation of the code with the results of the measurements, N.Sobolevskiy. 4.Use of the SHIELD code to model the beam losses into the accelerator equipment and surroundings, N.Sobolevskiy.

What is done? Task 1 Task 1 is finished in its measurement parts although still some more processing is needed Outcome 1: ATIMA modeling of the dE/dx seems to be the closest to the measurements Outcome 2: The ATIMA module should be incorporated into SHIELD The results were published as a GSI internal note, were presented in PAC05 and SHIM conferences and being prepared for publication in a scientific journal

What is done? Task 2 Part of Task 2: measurement of activation induced by 100 MeV/u and 500 MeV/u U ions on the stainless steel and copper targets is under way right these days The main difficulty we met: low level of activation and necessity of long irradiation time (main beam-time is required!) Unexpected results (report by A.Golubev)

What is done? Task 3 Simulations of the experimental set-ups with the help of the SHIELD code allowed not only good preparation of the experiments but also helped in interpreting the results of the measurements. It is desirable to include the ATIMA dE/dx modeling into the SHIELD. More details will be given in the presentation by Dr. Sobolevskiy The methodology of the measurements were presented in EPAC04 conference

What is done? Task 4 Radiation damage to the SIS100 dipoles were calculated Radiation damage to the SIS300 dipoles were calculated The results were published as GSI internal notes and presented in EPAC04 and PAC05 conferences The main outcome: the most tolerable beam loss limiting factor is not danger of quench but the lifetime of the radiation sensitive materials, like organics and semi- conducting diodes. The radiation hardness test of the semi-conducting diodes will be done at ITEP Moscow (not in the frame of this Project). The contract on this subject is almost ready to be signed between the GSI and ITEP.

What has to be done? Task 1 Task 1 is almost finished There are still measured data to be processed (especially in the 200 MeV/u case) Publication in a scientific journal (NIM, PRST?) should be prepared soon.

What has to be done? Task 2 Processing of the results of 120 MeV/u and 500 MeV/u irradiation Preparation of the 1 GeV/u activation measurements We should prepare journal publications on the activation measurements: it is required from STU Bratislava. We are preparing new INTAS proposal.

What has to be done? Task 3 ATIMA into SHIELD Understanding of the results of the activation experiments using the SHIELD code simulations Use of the other heavy-ion transport codes: PHITS, FLUKA, GEANT4 ?

What has to be done? Task 4 Although a lot has already been done in the frame of Task 4, there are still much more to be done according to the needs of the FAIR Project and this activity should be financed on much broader basis than just the GSI- INTAS funds Radiation damage to the quadrupoles of the SIS Radiation damage problems foreseen for the SFRS Radiation damage from the collimators: hardness of the surrounding equipment – pumps, electronics. Beam loss simulation of the injection-extraction points Neutron doses in and outside the tunnels of the SIS100 and SIS300 synchrotrons (RHIC problems: safety of the electronics and underground water activation)