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Collector work in Strasbourg. 2 contributions : preparation of horn tests and definition of supplies and infrastructure study of target integration and cooling local team : M. Dracos (group leader), F. Osswald* (technical coordinator) and collaborators :
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Collector work in Strasbourg 2 contributions : • preparation of horn tests and definition of supplies and infrastructure • study of target integration and cooling local team : M. Dracos (group leader), F. Osswald* (technical coordinator) and collaborators : T. Adam, G. Gaudiot, T. Goeltzenlichter, M. Krauth, C. Ruescas, J. Schuler, J. Wurtz * spokesman
horn, supplies and infrastructure • SB-SPL (νFact)* horn model to be considered, CERN’s horn prototype can be used to start • goals : fatigue tests of horn AND power supply at 50 Hz and progressive current up grade without beam. Numerical model validation in parallel for simulations and time&cost saving • financing : LOI sent for FP7, 1.35 Meuros for target and collector costs, available 2009 ? (target R&D, horn, target integration i.e. BENE WP3 and 4) * SuperBeam-Super Proton Linac for a neutrino factory
simulations Comsol (ex Femlab) software evaluation : compliance with the specific need of cross-disciplines = coupled PDE = multiphysics task of the EM horn submitted to electrical pulse, thermal and structural stresses temperature map for a simplified horn model
then... • fit model to experiment • design a new horn : 2→10 GeV (tbc) proton incident energy, define combined stresses and requested beam cooling (no garanty with actual CERN prototype)
pulsed power supply • status : design a 2MW system delivering 300 kA, 100 μs long pulses @ 50 Hz, identification of suppliers, no call for tender but discussions to evaluate feasability, delivery delay and cost • hybride and unique system composed of a capacitor charger, capacitive energy bank, pulsing system, electronic control, regulation interlocks and interfaces (connectors, bus bars, feedtroughs, impedance matching, protections)
capacitor charger 1/3 • switch mode power supply composed of a rectifier, a direct current link and a resonant circuit • main specifications (abstract) : power 1.7 MW aver. / 3.4 MW peak, charging current 500 A, energetic efficiency > 90 %, modular system (10-40 racks) is recommanded but compact charger (1-2 modules) not without interest, water cooling (200 kW)
capacitor charger 2/3 • miscellaneous : short and long term current and voltage stabilities (load and line voltage regulation, output voltage ripple, etc. ~ 0.1 %), charging time (≤ 19 ms), temperature coefficient < 0.02 %/°C, 24 H/day operation, 200 days/year, 8 108 pulses, EM compatibility, remote control → all these specs have a strong impact on cost, need to be confirmed with users !
capacitor charger 3/3 • cost < 500 k€ (with ER, specs dependent), delivery + test delay ~ 1 year, but additional delay due to financing ! • energy recovery option necessary due to electricity cost : 80 €/MWh (~ 100 k€/month without ER) ! In that case, 60 % initial voltage recovered, power and cost reduced by a factor ~ 4, charging current 130 A, but higher pulsing system cost (150→500 k€) • rental option, « system as it is », @ 1 kV (immediate and cheap) or up graded (delay) : 40 k€ + 10 k€ /year, Uni. of Gelsenkirchen (G)
capacitive energy bank • main specifications (abstract) : stored energy 35 kJ, charging voltage ± 7 kV, capacitance 1.5 mF, repetition rate 50 Hz, discharge current 15 kA RMS, operation time 24H/day, life time > 104 H, low resistance- inductance value units, self-healing techno. • cost 100 k€, delivery delay 6 months+ assembling&wiring
pulsing system 1/2 • based on discharge solid state switches, mainly thyristors, ABB contacted and R&D needed to confirm the design of a 50 Hz system (ref. Power electronics department, Lenzburg, CH) • main specifications (abstract) : 300 kA to be switched at 50 Hz, 8 108 * 100 μs long pulses, under 7 kV, low inductance system
pulsing system 2/2 • Switching delay ~ 1 μs • di/dt ≥ 10 kA/μs • power constraints 300 kA, 4 MW, 1,5 MA².s • voltage on capacitor +/- 7 kV • endurance 50 p/s ≡ 4,3 106 p/day ≡ 1,3 108 p/month • optical triggering • water cooling ~ 10 kW • reliability of energy recovery option to be demonstrated • cost < 500 k€ (with energy recovery system)
intermediate conclusion • no major problem but R&D needed for pulsing system and feasibility demonstration @ 300 kA & 50 Hz → thyristors cooling & integration • pulsed power supply cost : < 1100 k€, tolerance mainly due to thyristor R&D and charger specs • possible cost reduction : specs, international call for tender, (energy recovery option, already included) • delivery delay ≤ 1 year but financing delay to consider and R&D work → not too early to start now
supplies and infrastructure 1/2 • set up infrastructure, cost estimation, and organization of local team : 2 MW pulsed power converter housing, electrical network, 250 kW cooling and ventilation, safety, regulation, etc. ☻to be noticed : local scientific council (IPHC) agreement obtained last June
suplies and infrastructure 2/2 • example of test area with supplies cran, etc. • cost to up grade the plant ~ 250 k€ • building to host a test bench @ Strasbourg
target integration and cooling IPHC contribution to BNL&CERN experiment • goals : • maintain the integrity of a solid target despite the heating / 2ndary particle energy deposition + Joule effect of pulsed current circulation in the horn • integer the solid target into the horn • → evaluate the feasibility of a BNL, CERN&IPHC experiment, adapt material and size of target and its container to the current intensity and the power
status • preliminar specifications submitted by N. Simos (BNL) and I. Efthymiopoulos (CERN): limited items but broad range of test condition settings • 1st order calculations and global dimensions set up, temporary options → to identify needs/studies and trigger discussions
first specs (Nick’s) • target material options : AlBeMet, IG-43, Gum metal • test the target and container heat dissipation • use helium and water as heat dissipators • use DC currents to obtain the steady mean temperatures (target temp. • ~ 1000 °C) and superpose pulsed currents to evaluate the dynamic effect • define the dimensions of the target and container in order to reach the • test currents i.e. the dissipated powers ( ~ 100 kW ?) • define secondary parameters as flow, pressure, temp. increase, etc. • adapt the test bench to the CERN’s supplies
target test bench no use of electrical heater but direct heating through current feed to the target and its container to simulate beam and current heating of the inner conductor and target. Uniform heating, no exponential distribution/ energy deposition→ other alternative : charged particle or Laser heating ?
first virtual prototype 1/2 the actual design is a compromise between target dimensions, materials, HV/high current design, and performances, in order to reduce cost of power distribution (electricity, bus bars, connectors)
first virtual prototype 2/2 DC ampicity and 10’s kW heating (tbc) lead to high resistivity materials, long target (0.70 m, diam. 0.2 m) and ~ 10’s kA limited DC current (tbc)
next step • actual missing data : • fix the resistive power dissipated in the target • and its metallic container • fix the acceptable temperature shifts • define the interfaces / CERN’s equipments : • available power supply, distribution line, • helium circuitry, and connectors
conclusion • goals can be achieved following preliminar schedule (see Marcos’ talk, BENE SG, July 2006) • design of Power Supply : 2006-2007 • horn R&D, tests and simulations : 2006-2008 • new horn prototype : 2009 • schedule of solid target test to be defined • ... if financing and manpower available in time
references • talks : • BENE SG meeting at CERN, July 2006 • ISS meeting at Irvine, August 2006 • papers : • Study of particle production and capture for a neutrino factory, S. Gilardoni, CERN thesis, NuFact 141, July 2004 • Etude des faisceaux CNGS et identification des muons dans l’expérience OPERA. Optimisation de la ligne de faisceau du projet SPL-Fréjus, A. Cazes, Thèse LAL, December 2004 • G. Graewer, Investigation of the possibility to build a 400 kA pulse current generator to drive a magnetic horn, NuFact 38, July 2000 • IPHC test facility, F. Osswald & al., July 2006, to be published
remaining horn issues • multistress resistance • reflector integration and test • fatigue test • radiologic hardness • target integration • power supply design and test • energy recovery system