The first design of Medium resolution mass spectrometer (MRMS) High Voltage Platform in a SPES project. Stanislav Andrianov.

Medium resolution mass spectrometer (MRMS) platform cleans the beam from the contaminations introduced by the Charge Breeder itself. MRMS in SPES Facility.

Beam line 3.3x2.7 meter; Potential HVP= kV; SD1, SD2- magnetic dipoles; 1SQS1, 1SQS2: sestupole+quadrupole electrostatic lenses; 1SQ1-1SQ4 – quadrupole electrostatic lenses, SACC1, SACC2 – accelerating/deaccelera- ting tubes. Initial conditions.

Area for HVP zone 10.3x5 m; Min. distance between walls and HVP – 0.9 m; Passage out of the elevator in the experimental hall; Area for crane must be empty;

Area for HVP. 1.A metal staircase should be dismantled; 2.In some cases water pipes should also be dismantled; 3.Passage out of the elevator in the experimental hall; 4.Grid on the edge of balcony;

Platform design and placement of equipment on it. 1 level supporting on insulators (porcelain); HV potential 130 kV; Area 5.4 x 3.1 meter; Faraday cage 2.8 meter of height; Aluminium panels mounted on frame; 14 cm radius for sides and vertices;

Platform design and placement of equipment on it. 9 support insulators column (withstand 230 kV); Cables located in a false floor; Metallic ring on mid. Insulators; Equipment locating on a main level; Two 750 MΩ resistors between HVP & ground; beam height 2317 ± 0,7 mm

Platform design and placement of equipment on it. 4 RACKs with height 2m; 1 powerboard; Fire security tanks Equipment inside a RACKs; 1 vacuum board; Other servises: pumps, diagn. boxes, cooling, locks, alarms.

Platform design and placement of equipment on it. Indoor insulating transformer solution (for dry transformer); Outdoor insulating transformer solution (for oil transformer); The Equipment could be powered by different ways:

Platform design and placement of equipment on it. Motor-generator locate on a platforms; Generator platform – insulator (separate vibration); Vibration grade-S (ISO 2372); Connect by plexiglass shaft (insulator); Indoor motor-generator solution:

Power system. The specification of Equipment which consumes power shown in table. This equipment will be supplied via an isolation transformer (dry or oil or generator ) with characteristics: dielectric strength ≥ 156 kV (130 kV+ 20% spare); Power ≥ 49 kVA; Three phase output line; Type equipmentQ-tyTotal power [VA] Beam line elements+ power supplys Vacuum85400 Diagnostic boxes22500 Control units69000 UPS23000 Lighting, alarms, ventilation 2000 TOTAL %=48260 Output voltage AC ~ V;

Power system. 3 HV cable connected via a voltage regulator to the electrical switchboard. Grounding circuitry on HVP is carried out by IT scheme. 1)PS magnetic dipole SD1 (9kVA) + reserve 1kVA. 2) PS magnetic dipole SD2 (9kVA) + reserve 1kVA. 3)1SQ1-1SQ4 (480 VA)+ 1SQS1, 1SQS2 (480 VA) + 1SM1 (960 VA)+ PS Vacuum (5.4 kVA) +reserve (2680 VA). 4) Control units of elements (8kVA)+Control units of vacuum (1kVA)+ reserve (1kVA). 5)UBS (3 kVA)+ Diagnostic boxes (2.5 kVA)+ Lighting, alarms, ventilation (2 kVA) + reserve (2.5 kVA).

Power system. Power high-voltage generator must be ≥ 1.5 mA (with spare). High voltage generator must have remote control. The generator output is connected to the metal structure of the platform. Way of leakageCurrent Accelerating/decelerating tube resistance (150*10*2=3 GOhm each) 100×10 -6 A Cooling water circuit resistance. 1072×10 -6 A Resistors between ground and platform 100×10 -6 A Vacuum piping 4.3×10 -9 A Isolation columns 1.13×10 -9 A Motor/generator configuration 0.4×10 -9 A Insulating transformer configuration 12.8×10 -9 A TOTAL1.3 mA

Power system. Thus the total capacity of the equipment is powered from the central supply system will be in accordance with Table. High Voltage Generator500 VA Insulating transformer/ Motor- Generator 55 kVA (efficiency 90%~ 50 kVA) Water pump2 kVA Console+UPS1.5 kVA Ronda TOTAL≈60 kVA

Control units. Two consoles will be used to control the platform and equipment installed on it: a main console will be located in the main control room; service console will be located closed to the platform, outside the secondary Faraday cage. Control units must manage the following services on HVP: PS Magnetic dipole SD1 и SD2; PS electrical quadrupoles and hexapoles 1SQS1-1SQS2; PS Electrical doublet 1SQ1-1SQ4; PS Electrical multipole 1SM1; Vacuum pumps and gates; Position of diagnostic box; PS of steerers.

Control units. They must also display the following indications on control room: Flow and pressure in water cooling system; Pressure in a beam line; Currents in magnetic dipole and field in the magnets (Hall sensor); Electrostatic lenses voltage; Output signal of beam diagnostic equipment; Leakage current from the high voltage generator through the platform; High voltage on a platform; Position of HV disconnector; Isolation transformer status (t◦, on/off); Instant power of isolation transformer; Power board status (breakers state); Temperature in the HVP; State of ventilations system; Water conductivity. Also near the entrance for secondary Faraday cage should be placed console indicators: HV generator status; Interlocks status; Ronda status;

Cooling system. Water from the central water delivery system The central conduit pressure is 8 bars Plastic tube, ventels, gauges; Length of pipes 20 meters and 3 sm in diameter. Equipment on the platform requires a cooling water flow according to Table. Equipmentl/min Dipole SD17 7 dipole SD1 power supply10 dipole SD1 power supply10 Total34 Total with spare40

Cooling system. RACKs cooling air flow from the cooler. Power is determined from the ratio of the cooler approximately 200 [m 3 /hour] every 1 [kVA] electrical power. On the panel water is distributed on the equipment through the vents and gauges as shown in Figure:

Safety system and interlocks. HVP must be present on a several locks and alarms for safe startup and operation of the platform. Startup the high-voltage generator to be blocked in case of: Do not closed the door on the platform; Do not closed the door to secondary Faraday cage; Closing position of HV disconnector; Set of stairs at the entrance platform; Low vacuum in a beam line P≥10 -5 Pa; Negative status Ronda; Do not closed all removable covers on the platform; Lock hardware on a platform: Water locks of magnets and power supplies. Power Locks ES lenses in low vacuum P≥10 -5 Pa.

Safety system and interlocks. Ronda is a system of startup protection HV generator at the presence of people on the platform. When you perform a technique (until 5 min) to bypass the platform, Ronda set a positive status and enables HV generator. The technique is as follows: 1.Request for Rondo on the console (turn a key). Siren sounds. 2.Confirm the request by pressing on a button. 3.Opening and closing the door on a secondary Faraday cage. 4.On the opposite wall from the entrance pushing on rondo button. Siren sounds. 5.Opening and closing the door on the platform. 6.Pressing rondo button on HVP. 7.Opening and closing the door on the platform. 8.Installing stairs in a special area. 9.Installing grounding rod (if available) on second Faraday cage. 10.Opening and closing the door on a secondary Faraday cage. 11.Took a key from the console unit Ronda.

Safety system and interlocks. In the console area near the entrance to the platform should be the emergency stop button. It’s turns off everything equipment, including UPS (in HVP). Also on this console should be indicators/alarms: No water on the platform; Closed position HV disconnector; Increased temperature RACK # 1, RACK # 2, RACK # 3, RACK # 4; On/off HV generator; Satisfactory level of pressure in compression air pipes; On/off UPS; On/off isolation transformer. In the experimental hall is a crane. During operation the platform of his work should be blocked near the zone of HVP.

Vacuum system. (designed by Carlo Roncolato) Rough estimation on the pumps installed is 4 TMPs assisted by 2 Primary Pumps (PP). Additional Ion Pumps (IPs). In normal vacuum gas exhaust line pressure is variable from 100 to 900 mbar. In this pressure range the dielectric strength (of gas) decreases. If a normal vacuum gas exhaust line is on “ground”, electric breakdowns are possible. This line and tank should be located on roof of HVP

Vacuum system. Also vacuum system of HVP should include: N2 line; Compressed air line.

Conclusions. 1.The first design of MRMS HVP developed. most of the components and equipment defined; platform design geometry and placement defined. Structural and mechanical calculation has to be performed by civil/mechanic engineer; engineering services designed (power system, cooling, vacuum..); list of requirements for the system of protection and locking created; 2.Changing the beamline elements will not cause a significant change in the design platform. 3.The approximate specification of materials defined. 4.List of companies which producing the required equipments defined.

References [1] G. Prete, A. Covello SPES Project Technical Design Report INFN-LNL-223 (2008) [2] G. Prete, A. Covello SPES Executive Summary INFN-LNL-224 (2008) [3] M. Cavenago, T. Kulevoy, G. Abrioni, S. Canella, F. Cervellera, “The Legnaro ECR ion source platform” Heavy ion Accelerator Technology: Eighth International Conference, (1999) [4] Кухлинг Х. Справочник по физике: Пер. с нем. 2-е изд.- М.:Мир, [5] ISO 2372 (10816) [6]

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