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Page 1 L. Perrot,MYRRHA accelerator 1st International Design Review MYRRHA / CDT The MYRRHA HEBT L. Perrot : CNRS-IN2P3-IPNO MYRRHA.

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Presentation on theme: "Page 1 L. Perrot,MYRRHA accelerator 1st International Design Review MYRRHA / CDT The MYRRHA HEBT L. Perrot : CNRS-IN2P3-IPNO MYRRHA."— Presentation transcript:

1 Page 1 L. Perrot,MYRRHA accelerator 1st International Design Review MYRRHA / CDT The MYRRHA HEBT L. Perrot : CNRS-IN2P3-IPNO MYRRHA accelerator 1st International Design Review WP1 - GLOBAL ACCELERATOR DESIGN High-energy beam lines Starting point : -the Central Design Team (CDT) for a fast spectrum transmutation experimental facility (FASTEF), EURATOM, FP7, Grant Agreement N°: FP [1] -Deliverable D2.4 of the WP2, task 4. Accelerator design related issues Authors : J.L. Biarrotte, L. Perrot, H. Saugnac (CNRS), A. Ferrari (HZDR), D. Vanderplassche (SCK-CEN) Outlook : 1.Reference layout 2.Beam dynamic 3.Magnets 4.Beam Instrumentation 5.Mechanical design 6.Shielding and radioprotection 7.Additional issues

2 Page 2 L. Perrot,MYRRHA accelerator 1st International Design Review MYRRHA / CDT Introduction  The Central Design Team (CDT) for a fast spectrum transmutation experimental facility (FASTEF). It is the next step next after FP6 IP-EUROTRANS. European program : “FASTEF is proposed to be designed to an advanced level for decision to embark for its construction at the horizon of 2012 with the following objectives: to demonstrate the ADS technology and the efficient transmutation of high level waste; to operate as a flexible irradiation facility; to contribute to the demonstration of the Lead Fast Reactor technology without jeopardising the above objectives”  The Myrrha Accelerator eXperiment (MAX) : “To feed its sub ‐ critical core with an external neutron source, the MYRRHA facility requires a powerful proton accelerator (600 MeV, 4 mA) operating in continuous mode, and above all featuring a very limited number of unforeseen beam interruptions. The MAX team, made up of accelerator and reliability experts from industries, universities and research organizations, has been set up to respond to these very specific twofold specifications.” CDT = R&D reactor+HEBT MAX = R&D accelerator The R&D program for the accelerator to MYRRHA ? We will be focus on the design of the final beam line which aims to transport the 600MeV, 4mA proton beam from the LINAC exit -up to the spallation target located inside the reactor core, -up to the 2.4MW beam dump

3 Page 3 L. Perrot,MYRRHA accelerator 1st International Design Review MYRRHA / CDT HEBT :  Transfer line from accelerator to the spallation target  Prepare the beam spot requirements (shape, position, intensity and energy)  Transfer line from accelerator with the beam-dump  Provide a safe operation and maintenance 1. Reference layout

4 Page 4 L. Perrot,MYRRHA accelerator 1st International Design Review MYRRHA / CDT 1. Reference layout  General layout compatible with reactor building produced by Empresarios Agrupados, CDT WP3 (“Plant requirements”) [4]  Beam line to reactor: layout FROZEN  Beam line to dump: not fully finish 40m 30m 24m 26.5m 15m 38m downstream the LINAC tunnel Z=-2.5m ground Reactor 13 quadrupoles (L=0.5m, ⌀ 100mm, 3T/m max) 2 dipoles 45° (ρ=3.2m, gap 100mm, 22.5° edges) 1 dipole 90° (idem, 26.56° edges, radiation-hard) 16 DC steerers (L=0.3m, 150G max) 2 AC steerers (L=0.3m, 150G max) 11+ beam diagnostic boxes (11 BPMs / 8 Profilers / 1 ToF) 12 Collimators / Halo monitors 2 Beam Current Monitors 1 Near-Target Profiler (PSI-like) Scanning device From EUROTRANS [2] project, it was choosen the second conceptual design (less components and lowest high of the reactor building [3]. Dump Matching Object point 45° rectangular bending magnet 90° bending magnet Pole-face rot.=26.565° Quad triplet 20° bending magnet +2 quadrupoles -45° rectangular bending magnet

5 Page 5 L. Perrot,MYRRHA accelerator 1st International Design Review MYRRHA / CDT 1. Reference layout 40m 30m 24m 26.5m 15m 38m downstream the LINAC tunnel Z=-2.5m ground Reactor  14 quadrupoles (L=0.5m, ⌀ 100mm, 3T/m max)  2 dipoles 45° (ρ=3.2m, gap 100mm, 22.5° edges)  1 dipole 90° (idem, 26.56° edges, radiation-hard)  18 DC steerers (L=0.3m, 150G max), beam orbit correction  2 AC steerers (L=0.3m, 150G max) Scanning device Dump Matching Object point -45° rectangular bending magnet 90° bending magnet Pole-face rot.=26.565° Quad triplet 20° bending magnet +2 quadrupoles 45° rectangular bending magnet  Pipe aperture = 100mm, in dipole=95mm  Diagnostics boxes (in green), see later  Beam losses have to be < 1nA/m like SNS [5] for components activation and safe maintenance  Vacuum < mbar  At the target window mbar must be achieve (beam losses ~0.05nA/m)  In case of incident with the beam in the HEBT : T switch-off <50  s. Diagnostics

6 Page 6 L. Perrot,MYRRHA accelerator 1st International Design Review MYRRHA / CDT By construction, the line:  is achromatic at 1 st order (position & divergence on target independent of beam energy) : T16=T26=0 from LINAC to target  has telescopic properties at 1 st order (image size on target = 9 x object size at point 0) : T11=T33=9 between object point and target. Target beam size is control by the beam size at the matching object point 0.  Donut-shape beam footprint achieved with the AC scanning magnets. Circular movement with few tens of Hz  No focusing during the last 25m (reactor hall) 2. Beam dynamic studies O QP1-3 QP7-9 QP10-12 QP4-6

7 Page 7 L. Perrot,MYRRHA accelerator 1st International Design Review MYRRHA / CDT 2. Beam dynamic studies Beam phase space at the LINAC exit Beam phase space on the spallation window Without scanning : RMS X,Y =9mm 600MeV Protons beam envelopes at 3RMS, using TraceWin Code [6] Normalized emittances:  x =0.242,  y =0.234,  z =0.291 .mm.mard Without scanning Horizontal plane in blue, vertical plane in red T46 vertical dispersion O

8 Page 8 L. Perrot,MYRRHA accelerator 1st International Design Review MYRRHA / CDT 13kW/2.4MW -- Horizontal -- Vertical Target aspects: Why do you need the beam scanning ?  Beam scanning must be done in order to protect the Pb-Bi target window But :  No space is involved inside the reactor hall (no quad, no instrumentation)  Safety do not permit to install the scanning device after the last 90° dipole  Donut shape is impose by the Pb-Bi liquid target cooling  Maximum beam scanning amplitude is fixed by target windows + last 2 meters beam pipe penetration inside the reactor core  Scanning speed depend almost to target windows and Pb-Bi speed cooling Need to 2 scanning dipoles located before the last 90° vertical dipole the maximum amplitude have to be less than 150G with frequency close to 100Hz (not yet frozen) The scanning devices not yet design 25m Reactor Scanning 2. Beam dynamic studies Beam phase space on target with scanning Target window zone

9 Page 9 L. Perrot,MYRRHA accelerator 1st International Design Review MYRRHA / CDT 2. Beam dynamic studies Impact of a energy jitter  The beam target foot-print have to be not sensitive to primary beam energy variation, which is ensure by the first order achromatic line  But between dipole, beam shift centroide is dependant to T16. Therefore, dedicated instrumentation have to be install like collimators, ring losses or segmented collimators. X Plane Y Plane Collimators / rings Effect of a 0.5% beam shift energy (3MeV / 600MeV) Target window zone Beam spot movement “donut-shape” footprint  Use to a raster magnets on X and Y, using a (possibly redundant) set of fast steering magnets operated at frequencies of several tens of Hz  Central trajectory is continuously deviate. The ±9 mm RMS beam spot on target is moved around the window centre in a circular pattern of radius 20 mm.  Octupole expander solution is not feasible (see next slide)

10 Page 10 L. Perrot,MYRRHA accelerator 1st International Design Review MYRRHA / CDT Multipole beam expander ? Homogeneous beam density distribution can also be performed using a set of octupole magnets in front of the target: -The first set of octupoles (1 or 2) produces a square homogeneous footprint -An additional turned octupole transforms the square in circle => For MYRRHA, it seems extremely complicated (if not impossible) to implement This is a beautiful solution, but several drawbacks: -Produces a lot of beam halo => has to be located near the final target 1. Impossible in our case 2. Tested location: upstream. Unmanageable (unless a possible 2 nd order O-I system...?) -Extremely sensitive to any beam misalignment or beam size variation 2. Beam dynamic studies 120mm 60mm

11 Page 11 L. Perrot,MYRRHA accelerator 1st International Design Review MYRRHA / CDT Tuning method : 1.Set the magnets to their theoretical value, & send a very low duty cycle beam (10 -4 ) 2.Adjust DC steerers for orbit correction (alignment) 3.Adjust QP1-3 => tune beam waist on 0 w/ desired size (1mm rms), using 3 transverse beam profil detectors 4.Adjust QP7-13 => achromaticity optimization using beam position monitor, target optical diagnostic. 5.Adjust QP 4-6 => re-adjust desired beam size on target (9mm rms), check telescopic properties 6.Recheck alignment & switch on + tune scanning device for obtain the “donut-shape” on target 7.Increase step by step the beam duty cycle (chopper in the LEBT) 2. Beam dynamic studies O QP1-3 QP7-9 QP10-12 QP4-6

12 Page 12 L. Perrot,MYRRHA accelerator 1st International Design Review MYRRHA / CDT 2. Beam dynamic studies Statistical error study Static errors are randomly applied to: -Magnets (displacement, field error) -Input beam (position, divergence, energy, emittance, intensity, mismatch) The beam tuning procedure is simulated step by step: - static errors are corrected when possible - errors on beam diagnostics measurements are taken into account Dynamic errors (mechanical vibrations, stability... ) are then randomly applied: - These transient errors are not corrected - Applied to magnets (displacement, field error) & input beam (position, divergence, energy, emittance, intensity, mismatch) Iteration is performed to get good statistics: -100 different line configurations -each one with a tracking involving 10 5 macro-particles

13 Page 13 L. Perrot,MYRRHA accelerator 1st International Design Review MYRRHA / CDT 2. Beam dynamic studies 1. Nominal 99% envelopes without errors, without scanning Error calculations

14 Page 14 L. Perrot,MYRRHA accelerator 1st International Design Review MYRRHA / CDT 2. Beam dynamic studies 2. 99% envelopes with UNCORRECTED static errors (random distribution), without scanning Error calculations

15 Page 15 L. Perrot,MYRRHA accelerator 1st International Design Review MYRRHA / CDT 2. Beam dynamic studies 3. 99% envelopes with CORRECTED static errors (same random distribution), without scanning Error calculations

16 Page 16 L. Perrot,MYRRHA accelerator 1st International Design Review MYRRHA / CDT 2. Beam dynamic studies 4. 99% envelopes with CORRECTED static errors + uncorrected dynamic errors, without scanning Error calculations

17 Page 17 L. Perrot,MYRRHA accelerator 1st International Design Review MYRRHA / CDT 2. Beam dynamic studies Possible losses on collimator: - Min = 0, Max = 29kW - Mean = 0.3 kW, RMS = 3kW => Losses in 1% cases Losses on final tube: - Min = 0.5kW, Max = 110kW - Mean = 15 kW, RMS = 14kW from 10 7 particles Error calculations: beam losses

18 Page 18 L. Perrot,MYRRHA accelerator 1st International Design Review MYRRHA / CDT Mean orbit (X) Mean orbit (Y) RMS orbit (Y)RMS orbit (X) Error calculations: trajectories 2. Beam dynamic studies This error study is quite insufficient to get to definitive conclusions, but gives already good orders of magnitude for the required tolerances and a good feeling of the general situation. We need a end-to-end accelerator errors calculation

19 Page 19 L. Perrot,MYRRHA accelerator 1st International Design Review MYRRHA / CDT X rms size Y rms size Footprint (log scale) Footprint (linear scale) Error calculations: target footprint : fluctuations are considered acceptable 2. Beam dynamic studies

20 Page 20 L. Perrot,MYRRHA accelerator 1st International Design Review MYRRHA / CDT Error calculations: sensitivity 2. Beam dynamic studies Errors impacting the orbit excursion through the line (i.e. beam losses) 1.Beam energy jitter: ±1MeV => 5 mm rms deviation (DYNAMIC) 2.BPM precision: ±0.5mm => 2 mm rms deviation (STATIC) 3.Magnets alignement: ±0.3mm => 1 mm rms deviation (STATIC) 4.Dipole field stability: ± => 0.5mm rms deviation (DYNAMIC) Errors impacting the position on target 1. Input beam divergence jitter: ±0.01mrad => 0.7mm rms (DYNAMIC) 2. Input beam position jitter: ±0.1mm => 0.6mm rms (DYNAMIC) 3. Dipole field stability: ± => 0.5mm rms (DYNAMIC) 4. Quadrupoles mechanical vibrations: ±10  m => 0.4mm rms (DYNAMIC) 5. Beam energy jitter: ±1MeV => 0.3mm rms deviation (DYNAMIC) 6. Dipole mechanical vibration (Y): ±10  m => 0.2mm rms (DYNAMIC) Errors impacting the spot size on target 1. Quadrupoles gradient stability: ±10 -3 => 0.15mm rms (DYNAMIC) 2. Beam energy jitter: ±1MeV => 0.1mm rms (DYNAMIC) 3. Beam profiler precision measurement: ±0.5mm => 0.1mm rms (STATIC)

21 Page 21 L. Perrot,MYRRHA accelerator 1st International Design Review MYRRHA / CDT Beam line to dump Present layout of the line:  20° dipole to avoid neutron back streaming & ease the maintenance  2 quadrupoles to defocus beam on dump with 210mm diameter  240mm larger beam vacuum pipe along the final 6m Beam dump design  Preliminary design from the 1 MW PSI proton dump (larger)  Required shielding, preliminary study performed  Detailed mechanical & thermal assessments to be done  Power losses = 2-3kW/cm²  600MeV protons range in Copper = 25cm 2. Beam dynamic studies 15m Tuning the beam line from p-source up to HEBT (commissioning, tuning & check) 3s beam envelops

22 Page 22 L. Perrot,MYRRHA accelerator 1st International Design Review MYRRHA / CDT Quadrupoles 3. Magnets 2 series of quadrupoles : 14 for the beam main HEBT line (Q-50), 2 for the beam-dump line (Q-100)  Quadrupole design & size choose for minimize fringe fields & others higher orders contribution  Current density from 2 up to 10 A/mm²  Water cooling < 10 bars  Radiation-hard materials (low carbon steel) Design can be closed to the SNS quadrupoles

23 Page 23 L. Perrot,MYRRHA accelerator 1st International Design Review MYRRHA / CDT Dipoles 3. Magnets 600MeV protons => B  4 Tm => Dipole radius = 3.2m  4 magnets  3 angles of deviation : 20° (beam-dump line), 45° (x2) and 90° (up to reactor)  C-type magnets (except for 20° magnet)  Reliability have to be taking into account (coils design)  Radiation-hard materials especially for 90° and 20° magnet Design can be closed to the CNAO cancer therapy facility in Italy [7] POISSON calculation of a basic 90° dipole magnet for MYRRHA/FASTEF Field homogeneity is achievable in the “good field region”.

24 Page 24 L. Perrot,MYRRHA accelerator 1st International Design Review MYRRHA / CDT Steering and scanning magnets 3. Magnets Steering magnets are used for the orbit correction  DC power supply  Number = 18 (9 for horizontal plane, 9 for vertical plane)  Magnetic length = 30cm  Aperture = 110mm  Working range : -500G

25 Page 25 L. Perrot,MYRRHA accelerator 1st International Design Review MYRRHA / CDT Overview 4. Beam Instrumentation Beam diagnostics and control systems will be deployed all along the final beam transport line in order to tune the beam, maintain normal operation according to specifications, and protect the beam line equipments in case of malfunctioning. Main beam diagnostic devices along the HEBT  beam intensity measurement current monitors (accuracy <1%),  beam loss monitors for trigger interlocks for beam switch off (  T<1ms)  Optical system (VIMOS like system at PSI [9] for beam footprint on target monitor and survey. For MYRRHA, need a dedicated R&D  Couple of halo scrappers and wire profilers should also be used if possible (this will probably not be the case) in the last straight section for redundancy.  At the exit of the 90° bending magnet, halo monitors for checking the beam center and size are roughly correct.  Standard beam diagnostics (position and size) Diagnostics type and usage for beam transfer line

26 Page 26 L. Perrot,MYRRHA accelerator 1st International Design Review MYRRHA / CDT Few details 4. Beam Instrumentation PSI BPM: capacitive pick-ups or magnetic loops symmetrically arranged in the pipe wall Energy : ToF technique = 3 pick-up capacitive electrodes L=20 needed to obtain (/)<10-3 SPIRAL2 Beam profiler : electron secondary emission or wire scanner SPIRAL2 PSI Current : fundamental for the reactor monitoring SPIRAL2 PSI TM01-mode coaxial resonator (aluminum, with a 10μm coating layer of silver to improve the electrical conductivity) DCCT : average beam current ACCT : single bunch monitoring Halo & Losses : tuning phase + safety (machine protection) : <1nA/m loss level SPIRAL2 PSI ionisation chamber Loss Ring : particle interactions induce currents, size adapted to the beam size, material Cu, Ni, Mo or C, cooling may be necessary, sub-sections can be useful BLM : detectors implantation around the beam tube. 6 along the HEBT to ensure the 1nA/m loss level Target monitoring : measure the beam size + position close the target. Crucial & challenging measurement for MYRRHA Beam have to be monitored continuously (deviation from tight reference values and peak power density feed-back). Optical technic like VIMOS (at SINQ - PSI) or TIS (SNS): - Thermal incandescence - Cr/Al2O3 fluorescence - Optical transition radiation (OTR) - He fluorescence (from fill gaz in line)

27 Page 27 L. Perrot,MYRRHA accelerator 1st International Design Review MYRRHA / CDT 5. Mechanical design  First conceptual design of the whole high energy part of the line and its integration inside the reactor building.  We take into account the design of the reactor and the definition of the building  Separated in different parts, due to the various security constraints  Safety requirements have an important impact on the building design, the accessibility and the mounting/dismounting procedures

28 Page 28 L. Perrot,MYRRHA accelerator 1st International Design Review MYRRHA / CDT 5. Mechanical design Part 1 : -beam axis =+1.5m to the floor -Corridor 5m large -Beam line not centered (3m right) for accessibility -No crane -alignment done with “Laser Tracker” Part 2 : -45° inclined line, length = 30m -Part of the beam dump casemate in this hall -Crane of 50 tons capacity -BD line in a 20° deviation. Reduction of the neutrons backscattering and better access for the handling Part 3 : -Tunnel of 22 metres long, 6.5 metres large and 10 metres height -Crane of 50 tons capability, common with part mbar vacuum specification (not yet study) :  Vacuum components and fittings will be ConFlat® type  Turbo-molecular pumping group with 200 l/s capacity.  1 pump placed each 3m. Each component subjected to alignment adjustments (magnets, diagnostic boxes, collimators…) has to be installed using bellows allowing enough longitudinal and lateral displacement.

29 Page 29 L. Perrot,MYRRHA accelerator 1st International Design Review MYRRHA / CDT 5. Mechanical design Part 4 : 90° magnet zone -Backscattered neutrons from reactor => hot cell probably -Need to specific material, remote handling and nuclear waste capabilities -Pumping system of the vertical line & 90° dipole will be in this section (200l/s turbo + 16m 3 /h primary) -50 tons crane -Fast valve before and after concrete wall -Vertical port for beam foot-print detection system and/or neutron dump coming from reactor. Part 5 : Beam line inside the reactor hall -High activation zone. -Need complete isolation, full remote and lateral handling. -Less active components must be chosen -Reactor access imposed to dismount the line -No pumping system in this section  3 parts for the line  Alignment is a major concern  Vacuum at the spallation window fixed to mbar  2 Fast valves (15ms closing time) for protection against the window breaking and accelerator failure (like cryogenic accidents)

30 Page 30 L. Perrot,MYRRHA accelerator 1st International Design Review MYRRHA / CDT The beam dump casemate=Hot cell 15 m deep, concrete wall to 5m thickness, 20 tons crane 10 m 30 m 9 m A 2.4 MW, full power beam dump, based on the 1.2 MW PSI proton beam dump, is foreseen to allow the commissioning of the MYRRHA accelerator independently from the reactor.  The conceptual design of the MYRRHA beam-dump is taken from the 1.2MW PSI existing dump [10].  Dump is handled from the top using the common 50 tons crane (part 2 & 3).  Due to the 20° deviation. It is not necessary to dismount the line.  Beam power deposition on 6 blocks (PSI=4 blocks), length=3m  Material : Copper but need to be optimized considering the high level of activation. High density carbon fiber surrounded by stainless steel can by a useful alternative 5. Mechanical design Part 6 : Beam line casemate: Conceptual design Structure of the 1.2 MW PSI proton beam dump

31 Page 31 L. Perrot,MYRRHA accelerator 1st International Design Review MYRRHA / CDT The goal of the shielding design is to guarantee that, under normal operational conditions, the added integrated dose to anybody working around the FASTEF/MYRRHA accelerator is extremely small, i.e. comparable or smaller than the natural background. To reach this goal one must rely on:  the use of conservative beam loss assumptions;  the use of a conservative shielding model;  the assumption of an occupancy factor = 1, that means 2000 hours/year occupancy close to the outer shielding wall (at the maximum dose rates). First evaluations have been performed during the PDS-XADS project, considering a continuous 1 nA/m proton loss at 600 MeV. This is equivalent to a mean beam loss level of about 0.6 W/m. 6. Shielding and radioprotection Required concrete/earth combined thickness at 600 MeV to reach the 0.5 μSv/h dose rate level. For 600MeV protons  Shielding issues in the reactor building impact strongly on the 90° dipole shielding. Concrete walls and roofs up to 5 m thick would therefore be needed to reach the 0.5 μSv/h dose rate outside the facility.  Shielding issues around the beam dump : the BD design must satisfy the shielding requirements & minimize the backscattered neutron & minimize the BD activation

32 Page 32 L. Perrot,MYRRHA accelerator 1st International Design Review MYRRHA / CDT Main problems :  Activation of the elements devoted to the beam absorption (beam dump)  Activation of the material of the line due to beam losses Calculations preformed using the FLUKA MonteCarlo code [11] which give : -Particle fluences -Ambient dose equivalent -Time evolution of the activation products (build-up and decay of radionuclides) 6. Shielding and radioprotection Activation Neutron fluence (n/cm 2 per beam proton) in and around the target Calculation on various “targets” (Carbon, Copper, AlSl-316L, Aluminium, Iron) Residual dose rate around the carbon target, at different cooling times Residual (in μSv/h) around 100 m beam- line, for two representative cooling times after a short and a long-term irradiation.

33 Page 33 L. Perrot,MYRRHA accelerator 1st International Design Review MYRRHA / CDT Full absorption of the 600MeV protons beam We have already presented a structure closed to the 1.2MW PSI beam-dump. Advantage of the know how but secondary neutrons and activation are very high. We have explore an alternative solution for the safety studies with a soft material as dump core (Carbon) surrounded by a high-Z shielding structure (stainless steel). Smaller neutron yield and less activation problems. 6. Shielding and radioprotection Optimisation of the beam dump zone Neutron fluence (n/cm2 per primary proton) in the dump concrete cage of the dump casemate Copper core Carbon core + stainless steel Dose rate (in mSv/h) Copper core Carbon core + stainless steel The soft Carbon core solution is clearly a good candidate Beam dynamic and mechanical integration not yet study

34 Page 34 L. Perrot,MYRRHA accelerator 1st International Design Review MYRRHA / CDT The building detailed definition is still in progress, and will probably keep moving slightly until the start of the MYRRHA construction. It is therefore important to ensure that the beam line layout will be able to adapt to these changes as much as possible without major consequences. 7. Additional issues Adaptation of the final layout Possible beam line adaptations in the case of a reactor height increase Study of a radiatively cooled cold window Vacuum protection of the final beam line in case of a target window failure Third passive protection in addition to the fast valves : use a thin metallic foil able to sustain high temperature gradients without perturbing too much the beam optics. In existing (low-power) accelerators, titanium foils of a few hundreds of μm are typically used. Study of a 100mm diameter 400  m thick Titanium using LISE++ code [12]. E loss =0.33MeV, P loss =1.3kW => fusion of the window (need to have a 30cm beam size (including halo) which is not reasonable. Using a cold window seems to be quite unrealistic Study of a water cooled cold window J-PARCESS prototype SNS/JPARC : Inconel 718 (1.5 to 2 mm thickness) separated by a 1.6 to 3 mm gap in which water flows (at typically 10 bars) ESS project : Aluminum tube cooled by Helium at 40 bars Apply to our case with the SNS/JPARC solution, P loss =27kW  Beam emittance increase by a factor 10 (  x’,y’ from 0.4mrad up to 4mrad) => not compatible with a window location at 25m up to the spallation window  Activation of this cold window  Need to be located very near the target itself SNS feedback can be an extremely important issue for MYRRHA

35 Page 35 L. Perrot,MYRRHA accelerator 1st International Design Review MYRRHA / CDT The goal of the MYRRHA/FASTEF final high ‐ energy beam line is to safely inject the proton beam onto the spallation target located inside the reactor  Consolidated design of the beam line to reactor achieved  AC steering magnets are preferred for the beam scanning  Error study shows very robust behavior (sensitivity in the X-plane may be optimised)  Need start-to-end error studies  Near-target optical device appears to be mandatory to be able to correctly tune and monitor the beam shape on target.  First detailed mechanical design is described for each part of the line  First shielding and activation calculations have been performed  Beam dump design on-going, need to be study in details (structure…) Conclusion HEBT for the MYRRHA project A beam line from the LINAC up to the reactor

36 Page 36 L. Perrot,MYRRHA accelerator 1st International Design Review MYRRHA / CDT 1.J.L. Biarrotte, L. Perrot, H. Saugnac (CNRS), A. Ferrari (HZDR), D Vanderplassche (SCK-CEN), Accelerator design related issues, February 2012, deliverable D2.4 of the WP2 task 4 to the CDT project, Seventh Framework Program EURATOM, Grant Agreement N° FP J-L. Biarrotte et al. – “Accelerator design, performances, costs & associated road-map”, Deliverable (D1.74) of the EUROTRANS project, March L. Mansini – Minutes of the CDT WP2 3rd technical meeting, Mol, November Drawings package N° by Empresarios Agrupados. 5.J. Galambos – “Operational experience with high power beams at the SNS superconducting linac”, Proc. of the LINAC’2008 conference, Victoria, Canada. 6.TraceWin Code : 7.W. Beeckman et al, “Magnetic design improvement and construction of the large 90° bending magnet of the vertical beam delivery line of CNAO”, Proc. Of the EPAC 2008 conference, Genoa, Italy. 8.M.E. Schuze et al., “Testing of a Raster Magnet System for Expanding the APT Proton Beam”, Proc. of the PAC’99 conference, New York, USA. 9.K. Thomsen, “VIMOS beam monitoring for SINQ”, Proc. of the DIPAC’2009 workshop, Basel, Switzerland. 10.See 11.A. Ferrari, P. Sala, A. Fassò, J.Ranft, “FLUKA: A multi-particle transport code”, CERN (2005), INFN/TC_05/11, SLAC-R O.B. Tarasov, D. Bazin, “LISE++: Radioactive beam production with in-flight separators”, NIM B 266 (2008) 4657–4664. References


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