February 24, 2003PDR on Muon Elx Services - A. Lanza1 MDT – TGC power supply system HV distribution Cabling and connectors Specifications for distributors Power consumption, cooling and mechanics Tests in B field and in radiation environment Control and monitoring Costs Production schedule Conclusions

February 24, 2003PDR on Muon Elx Services - A. Lanza2 MDT HV distribution Communications Primary power supply HV channels USA15

February 24, 2003PDR on Muon Elx Services - A. Lanza3 Communications Primary power supply HV channels USA15 MDT HV distribution 1172 MDT chambers, 656 in the Barrel and 516 in the Endcaps. Almost the totality is composed of 2 multilayers. 260 MDT in the Barrel and 100 in the Endcaps have 4 tube layers/multilayers. The remaining MDT have 3 layers/multilayers. Each layer is connected to HV by means of a SHV connector placed on the Faraday cage, so for each chamber there are 8 (or 6) SHV connectors. BarrelEndcap Chambers layer chambers layer chambers HV connections

February 24, 2003PDR on Muon Elx Services - A. Lanza4 Communications Primary power supply HV channels USA15 MDT HV distribution Splitter boxes: In order to be able to disconnect single layers in case of wire short-circuit, HV is connected to chambers through splitter boxes. Each box receives two HV inputs from distributors, and splits them in 3 (for 3-layers) or 4 (for 4-layers). Each box supplies one MDT chamber, and is placed close to chamber, in an accessible space (crossplate for many Barrel chambers). Small Wheels have special modularity, one box every 10 chambers. Total number HV inputs/box HV outputs/box 4-layer splitter boxes layer splitter boxes Small Wheel Splitter boxes 81664

February 24, 2003PDR on Muon Elx Services - A. Lanza5 Communications Primary power supply HV channels USA15 MDT HV distribution Distribution modules: The single HV channel is a DC-DC converter, 4 1 mA, working in B up to 0.08 T and in radiation environment. It is supplied by external power, 48 V DC. Each module is composed of 9 HV channels, individually programmable, and of a simple controller (Atmel chip). able to handle the HV parameters of the module. Its width should be 6 TE (1 TE = 5.08 mm), and its height 6U (266 mm). Its depth should be 24 cm (connectors excluded), in order to provide water cooling on the back of crates. This constraint is due to TGC. Output connectors are SHV. Module power supply is taken from the 48 V DC. At present there are two solutions for distributing power supply: using a backplane or using flat cables put in front of modules. The choice is also related to the cooling technique implemented. WidthHeightDepth HV channels Distributor 6 TE (30.5 mm) 6U (266 mm) 240 mm9 Master Controller 15 TE (76.2 mm) 6U (266 mm) 240 mm

February 24, 2003PDR on Muon Elx Services - A. Lanza6 Communications Primary power supply HV channels USA15 MDT HV distribution Distribution crates: They host 10 HV modules and a Master Controller module (width 15 TE). The height is 6U. With 90 HV channels/crate, 27 crates are needed for all MDT. One rack can host up to 5 crates. 6 racks are sufficient for the complete MDT system. Master Controller receives the communications lines from a Branch Controller (RS-485 protocol, 3 twisted-pairs), and power supply for optocouplers (+/- 12 V, few tens of mA) Distribution crate HV modules HV channels Master Controllers Total number of crates Total number of racks

February 24, 2003PDR on Muon Elx Services - A. Lanza7 Communications Primary power supply HV channels USA15 MDT HV distribution System mainframe: The 27 distribution crates are controlled by just one mainframe, type CAEN SY1527. Communications with Master Controllers are handled by Branch Controllers, each one driving up to 16 Master Controllers. 2 Branch Controllers (1 SY1527 slot each) are required to control the whole MDT system. On one SY1527 there are 16 slots available. Parameter settings can be changed by means of the internal keyboard (password protected), or remotely, via Ethernet or RS-232 connections. System Mainframe Total number of mainframes Branch Controllers Maximum handled crates 1, type SY1527 or SY2527 2, 1 slot each32

February 24, 2003PDR on Muon Elx Services - A. Lanza8 Communications Primary power supply HV channels USA15 MDT HV distribution Primary power supply: It is composed of AC-DC power supplies, 230 V AC input (or 400 V AC) and 48 V DC output. It should be placed in USA15. Cables 120 m long are needed to connect to the distribution crates. Modularity is not yet defined. For MDT, power required by each crate at maximum current is ~ 550 W, but the calculated power dissipated by the detector is 3 kW, so the required output current for the primary power supply is 65 A. For TGC, power required by each HV + LV crate is ~ 500 W, but the whole detector requires 2.1 kW (HV) plus 34 kW (LV) plus 7 kW (controllers and logic). Output current of the primary power supply must be 900 A. Primary power supply, 48 V DC output Total required power Number of units MDT3 kW (65 A) 4 minimum, 27 maximum TGC 2.1 kW (HV) + 34 kW (LV) + 7 kW (Controls) = 900 A 45 minimum, 80 maximum

February 24, 2003PDR on Muon Elx Services - A. Lanza9 1/24 of TGC2 and TGC3 Communications Primary power supply HV channels LV channels 1/12 of TGC1 USA15 TGC HV and LV distribution

February 24, 2003PDR on Muon Elx Services - A. Lanza10 1/24 of TGC2 and TGC3 Communications Primary power supply HV channels LV channels 1/12 of TGC1 USA15 TGC HV and LV distribution TGC1 are subdivided in 2 sides of 24 blocks, each one composed of 27 chambers. TGC on Inner Layer are 192. TGC2 and TGC3 are subdivided in 2 sides of 24 blocks, each one composed of 44 chambers. Total TGC chambers are Each chamber is connected to HV by means of one SHV connector. TGC front-end requires 5 different types of power supplies: A A A A A Maximum power supplies provided currents must be 40% more than maximum drawn currents, so the target values are: A A A A A

February 24, 2003PDR on Muon Elx Services - A. Lanza11 1/24 of TGC2 and TGC3 Communications Primary power supply HV channels LV channels 1/12 of TGC1 USA15 TGC HV and LV distribution Inner Layer Sector 1Sector 2Sector 3 Number of chambers Crates 4 HV + 4 LV 12 HV + 12 LV 24 HV + 24 LV Chambers/c rate HV modules/ crate 665 LV modules/ crate 353 Inner Layer TGC are supplied from standard 19” crates in 2 racks in UX15. Each crate contains a mix of HV and LV modules. For TGC1, there will be 2 crates for each 1/12 sector, that will provide HV to 54 chambers and power to the PS-packs, as well as to the crate containing the High P(t) trigger and Star-Switch crate. In order to supply 1 block of 54 chambers, 6 HV modules of 9 channels each (same modules as for MDT, 6U high and 6 TE large) and 5 LV modules (6U high and 15 TE large) are needed. Each crate also needs a Master Controller. In principle this could also be accommodated with one standard 19” crate and an additional ½ crate. Power supplies for TGC2 and TGC3 could be place (very tight) in two 19” crates or a one + ½ crate with height not exceeding 30 cm and 35 cm in depth.

February 24, 2003PDR on Muon Elx Services - A. Lanza12 1/24 of TGC2 and TGC3 Communications Primary power supply HV channels LV channels 1/12 of TGC1 USA15 TGC HV and LV distribution System mainframe: TGC power supply system is composed of 56 standard 19” and 24 ½ distribution crates, subdivided in 8 standard crates for Inner Layer (mixed HV + LV), 24 standard crates for TGC1 (mixed HV + LV) and 24 standard crates + 24 ½ crates for TGC2 and TGC3. All distribution crates are controlled by one mainframe, type CAEN SY Branch Controllers (1 SY1527 slot each) are required to control the whole TGC system. Parameter settings can be changed by means of the internal keyboard (password protected), or remotely, via Ethernet or RS-232 connections.

February 24, 2003PDR on Muon Elx Services - A. Lanza13 USA 15 Communications Primary power supply HV channels MDT cabling – connectors In between splitter boxes and chambers: Cables – RG58 HV, ø 5.2 mm, length 1 ÷ 2 m, total number Connectors on Faraday cages – SHV (for BIL/BIM/BIR chambers there are no connectors, due to lack of space), one each layer. Connectors on splitter boxes - AMP Mate-n-Lock UL94V-2, 10 kV DC withstanding voltage, 3-pin body (central pin extracted for more clearance between ground and HV). One connector each SHV.

February 24, 2003PDR on Muon Elx Services - A. Lanza14 USA 15 Communications Primary power supply HV channels MDT cabling – connectors In between distribution crates and splitter boxes: Cables – RG58 HV, ø 5.2 mm, length 20 ÷30 m, total number Connectors on splitter boxes – SHV, one each HV channel. Connectors on HV distributors – SHV, one each HV channel.

February 24, 2003PDR on Muon Elx Services - A. Lanza15 USA 15 Communications Primary power supply HV channels MDT cabling – connectors In between SY1527 mainframe and distribution crates: Cables – 4 twisted pairs individually screened, round, ø 9.2 mm, length 120 m. 3 pairs used for communications (RS-485), 1 for optocouplers power supply. Total cables 27. Connectors on Master Controllers – not yet decided. Probably D-SUB. Connectors on Branch Controllers – as above.

February 24, 2003PDR on Muon Elx Services - A. Lanza16 USA 15 Communications Primary power supply HV channels MDT cabling – connectors In between primary power supply and distribution crates: Cables – screened power cables, ø not yet defined, length 120 m, total number not yet defined. Using standard 1000 W units, MDT need 4 (7 crates per unit), while TGC need 45 (1 LV crate per unit and 1 HV crate per unit). Connectors on distribution crates – not yet decided. Connectors on primary power supplies – not yet decided, probably screwed terminals.

February 24, 2003PDR on Muon Elx Services - A. Lanza17 Specifications Distribution module basic specifications: Output voltage range from 0 to 4000 V. Working voltage depends on the gas mixture and gas gain. At present, MDT baseline gas is Ar-CO 2 93% - 7% and gain is 2·10 4, so working voltage is 3080 V. It can increase up to 3.6 kV using other gas mixtures or increasing gas gain. TGC gas is CO 2 – n-C 5 H 12 55% - 45% and the working voltage is 2.9 kV, allowing operation in quasi- saturated mode (10 6 ). Required setting and monitoring resolutions are 1 V (12 bits). Output current from 0 to 1 mA for MDT, and from 0 to 200  A for TGC. For MDT, the calculated maximum sink current for the hottest chamber, an EIL, is 0.75 mA (taking in account a safety factor 5 for background simulations, a factor 1.6 for peak luminosity fluctuations, and a factor 2 for optional luminosity increase). Required monitoring resolution is 250 nA (12 bits) for MDT and 50 nA for TGC. Setting resolution can be 4  A (8 bits) for MDT, and 1  A for TGC. Due to the great difference of current requirements between MDT and TGC, and to the high current value for MDT, the chosen design typology for the HV base channel is based on DC-DC converters. It offers great flexibility (current increase requires only few resistor replacement) and allows savings in cables and power consumption in cavern. Its cost is even less than linear regulators.

February 24, 2003PDR on Muon Elx Services - A. Lanza18 Specifications Maximum allowed peak-to-peak noise is related to the detector stray capacitance, around 60 pF for the longest MDT. With a preamplifier peaking time of 17 ns, noise should be less than 20 mV in the frequency range of standard switching power supplies, up to 100 kHz. Comparison noise measurements on chambers in H8 testbeam are foreseen this summer. TGC show higher capacitances, but provide a very high signal charge, so they are less sensitive to noise than MDT. System stability over temperature should be 1‰/°C. System long-term stability should be 1‰/month. Ground decoupling for MDT is implemented inside splitter boxes. HV is connected to chambers by means of 1 k  resistor on both ground and hot lines, and bypassed by a HV capacitor. TGC HV ground is decoupled from signal ground internally to chambers.

February 24, 2003PDR on Muon Elx Services - A. Lanza19 Specifications Detailed specifications of the HV channel 4 1 mA (SASY2000 prototype)

February 24, 2003PDR on Muon Elx Services - A. Lanza20 Specifications Detailed specifications of the LV channel A (SASY2000 prototype)

February 24, 2003PDR on Muon Elx Services - A. Lanza21 Specifications Detailed specifications of the LV channel +4 65A (SASY2000 prototype)

February 24, 2003PDR on Muon Elx Services - A. Lanza22 Specifications Detailed specifications of the LV channel A (SASY2000 prototype)

February 24, 2003PDR on Muon Elx Services - A. Lanza23 Specifications Detailed specifications of the LV channel A (SASY2000 prototype)

February 24, 2003PDR on Muon Elx Services - A. Lanza24 Power consumption, cooling and mechanics TGC power consumption: HV channel = 0.8 W (at full load) HV module = ~ 15 W HV crate (6 modules) = ~ 150 W LV pack= for 44 chambers: 400 W required, 770 W maximum installed; for 54 chambers: 460 W required, 830 W maximum installed HV + LV crate (5 HV modules + 3 LV modules) = ~ 500 W (required), ~ 930 W (installed) HV system = 2.9 kW (installed)+ Controllers LV system = 34 kW (required), 63 kW (installed)+ Controllers Whole system = ~ 43 kW (required), 73 kW (installed) MDT power consumption: HV channel = 4 W (at full load) HV module = ~ 50 W (all HV channels fully loaded) HV crate = ~ 550 W maximum (including Master Controller) HV system = ~ 14 kW (maximum installed) HV system = ~ 3 kW (calculated peak power)

February 24, 2003PDR on Muon Elx Services - A. Lanza25 Power consumption, cooling and mechanics Distribution crate mechanics: Standard 19” crate, height 6U. No power supply unit. Possible special crate, 90 cm large, for TGC2 and TGC3. Distribution crate cooling: By water. Due to TGC constraint in depth, heat exchangers should be placed on back of crates, instead of top. Their depth cannot exceed 3 cm, and they have to be made by aluminum. Cern ESS already started studying similar problems, and realized a vertical cooling prototype, shown in pictures. This prototype is too thick for our requirements, and should be shortened to 3 (max 4) mm, if possible. Another solution could be the use of tangential fans, working in moderate magnetic field, together with water heat exchanger placed on top. Again, this heat exchanger must be thin enough to fit into the TGC available splace, 30 cm in height, crate included. Vertical water cooling prototype for 9U crates designed by ESS

February 24, 2003PDR on Muon Elx Services - A. Lanza26 Tests in B field and in radiation environment At present, we got a HV prototype from Caen since April It is composed of one master board, hosted in a SY1527 mainframe, and one distributor board. This last is the distributor designed for CMS drift tubes, (48 HV channels), and is equipped with 8 linear regulators, 2 – 4 1 mA, and 8 DC-DC converters, 2 – 4 1 mA. Master board is linked to distributor with four different connections: LV bus (power supply for distributor) Communications bus and power supply for optocouplers 48 V DC (primary power supply for DC-DC converters) 4 kV (primary power supply for linear regulators) All connections are realized with 100 m long cables. The prototype was operational in H8 testbeam since September 2002, but due to other priorities (combined run) it was not possible to test it using the MDT chambers. In October, some measurements of induced noise were done. This prototype is now going to Louvain– la-Neuve for rad hard tests under proton and neutron beams. For May 2003 we expect to receive from Caen a second prototype, a SASY 2000 system with 4 LV power supplies (see specifications above) and 8 HV channel, all made by DC-DC converters.

February 24, 2003PDR on Muon Elx Services - A. Lanza27 Tests in B field and in radiation environment Both HV and LV DC-DC converters were tested many times in B field at Cern. In particular, CMS RPC people, in collaboration with Caen, tested at Cern in 2002 a SASY 2000 prototype composed of 2 HV channels (12 1 mA) and of 2 LV channels (7.5 2 A). The results are shown below. Test conditions: 0 < B ≤ 0.5 T SA2001 V OUT = 8 kV, R load = 12 M  SA2002: V OUT0 = 4.7 V, V OUT1 = 5.0 V, I OUT0,1 = 1.9A Results: At 0.5 T: loss of efficiency 2% (// B) and 0% (  B) Efficiency defined as  = P load /P DC-DC converter (75%  73%) Magnet used: MNP24-1 in Cern Bldg. 168, able to produce a B field up to 1 T From Atlas maps, the upper limit for B in the region around the Barrel and the Endcaps at 12 m from the interaction point, which is where the power supply racks are placed, is 0.08 T.

February 24, 2003PDR on Muon Elx Services - A. Lanza28 Tests in B field and in radiation environment Radiation background in Atlas is very high. From simulations, the upper limit values in the region around the Barrel at 12 m from the interaction point, taking in account all safety factors, are: TID = 220 Gy SEE = 2.2·10 11 h/cm 2 NIEL = n/cm 2 The TID value seems to be overestimate, and a lower value, 80 Gy, is proposed. Discussions with Atlas rad-hard Coordinator, F. Anghinolfi, led to a policy for rad-hard prequalification of the HV – LV systems, consisting of: irradiation with protons at Cyclone (Louvain-la-Neuve) of at least 4 DC-DC converters and communications – controller components of the distributor up to 2.2·10 11 protons/cm 2, in order to satisfy the SEE request. This proton fluence is equivalent to a TID of 320 Gy, 1/3 more than necessary dose, and to a NIEL of 3.5·10 11 neutrons/cm 2, 3 times less than the required dose; successive irradiation with neutrons at Cyclone (Louvain-la-Neuve) of the same components with a total fluence of 3·10 11 n/cm 2, in order to reach the required NIEL. Production rad-hard qualification will require irradiation of at least 10 distributors.

February 24, 2003PDR on Muon Elx Services - A. Lanza29 Tests in B field and in radiation environment Both HV and LV distributors, designed for other detectors, were extensively tested under radiation. The HV prototype for CMS Muon Barrel detector, identical to our present HV prototype, but with linear regulators, was tested under protons in Louvain-la-Neuve. The accumulated doses were: TID = 70 Gy SEE = 5·10 10 p/cm 2 NIEL = 8·10 10 n/cm 2 not sufficient for Atlas qualification. No damage was induced. A SASY 2000 prototype, with 1 HV module (2 channels, 12 1 mA) and 3 LV modules (7.5 2 A), was tested under neutrons in Louvain-la-Neuve by CMS – Atlas RPC groups. Total dose was: NIEL = 1.8·10 11 n/cm 2 again, too low for Atlas qualification. All critical components worked well, only an optocoupler, used to enable channels, was damaged. It was replaced by a rad-tol equivalent. Next March, our HV prototype will be tested in Louvain-la-Neuve under protons, and in April under neutrons, so to understand the reachable radiation limits.

February 24, 2003PDR on Muon Elx Services - A. Lanza30 Noise test Last October we measured the noise distribution of the HV prototype, using a digital oscilloscope able to calculate and display FFT. Output voltage was attenuated by a factor of 15.8 with a 4.4 M  resistor divider. Amplitude of noise at 125 kHz for single DC-DC channel ON at 3.5 kV DC-DC0DC-DC3DC-DC6 125 kHz51.8 mV36.7 mV37.9 mV Current on SY  A799  A DC-DC # 0 DC-DC # 6 with all channels ON Only DC-DC6 at 3.5 kV 125 kHz  37.9 mV DC-DC6 at 3.5 kV + all other unloaded channels at 4 kV 125 kHz  74.6 mV

February 24, 2003PDR on Muon Elx Services - A. Lanza31 Control and monitoring TerminalFront-EndCommandFront-End TCP/IP RS232 Local Telnet Client ANSI Terminal Front panel Interactive control of SY1527 can be implemented by means of three different protocols: local keyboard on front panel local keyboard on front panel serial RS-232, using an ANSI terminal or a terminal emulator serial RS-232, using an ANSI terminal or a terminal emulator TCP/IP, using any Ethernet connection TCP/IP, using any Ethernet connection

February 24, 2003PDR on Muon Elx Services - A. Lanza32 Control and monitoring TerminalFront-EndCommandFront-End RS232 TCP/IP Std Drivers & Libraries Lab-View OPC Server OPC Client Client Custom Applications SY1527 can be remotely controlled via RS-232 or TCP/IP, using an open interface server called OPC (OLE for Process Control), developed by Caen and Cern. OPC client applications can communicate with OPC server to exchange data and control commands in a standardized environment. OPC server can use any communications link, RS- 232, TCP/IP or H.S. Caenet.

February 24, 2003PDR on Muon Elx Services - A. Lanza33 Control and monitoring TCP/IP LAN OPC LAN Telnet ClientLabView on PC/MAC Internet Router WAN Link ETH I/F OPC Server (via RS232) RS232 I/F Custom HV Distr. Detector OPC Server (via TCP/IP) OPC Client HV/LV Out Custom HV Distr. Custom HV Distr. HV+Control Telnet Client Possible ways of integration of SY1527 mainframe in a DCS

February 24, 2003PDR on Muon Elx Services - A. Lanza34 System costs Many items contribute to the system total cost. Here a first approximation is done for MDT and TGC. MDT – 27 distribution crates, 4 48 V units: HV cable from distributors to splitters, and from splitters to chambers: 80 km = 96 kCHF HV cable from distributors to splitters, and from splitters to chambers: 80 km = 96 kCHF SHV connectors for HV cable: 4800 = 43 kCHF SHV connectors for HV cable: 4800 = 43 kCHF 48 V power supply cable: 0.5 km = 5 kCHF 48 V power supply cable: 0.5 km = 5 kCHF Communications cable: 3.5 km = 7 kCHF Communications cable: 3.5 km = 7 kCHF HV system: 2500 channels (100 spare and for tests) = 500 kCHF HV system: 2500 channels (100 spare and for tests) = 500 kCHF 48 V power supply: 4 units = ? 48 V power supply: 4 units = ? Cooling system: 27 units = ? Cooling system: 27 units = ? TGC – 80 distribution crates, V units: HV cable from distributors to chambers: 100 km = 130 kCHF HV cable from distributors to chambers: 100 km = 130 kCHF SHV connectors for HV cable: 7200 = 80 kCHF SHV connectors for HV cable: 7200 = 80 kCHF 48 V power supply cable: 5.5 km = 55 kCHF 48 V power supply cable: 5.5 km = 55 kCHF Communications cable: 6 km = 12 kCHF Communications cable: 6 km = 12 kCHF HV system: 3600 channels = 700 kCHF HV system: 3600 channels = 700 kCHF LV system = 385 kCHF LV system = 385 kCHF 48 V power supply: 45 units = ? 48 V power supply: 45 units = ? Cooling system: 80 units = ? Cooling system: 80 units = ?

February 24, 2003PDR on Muon Elx Services - A. Lanza35 Production schedule MDT installation TGC installation

February 24, 2003PDR on Muon Elx Services - A. Lanza36 Conclusions MDT and TGC power supply systems are close to the final design. In particular: System architecture is defined, and it will be completed when SASY 2000 prototype will be operational, in summer 2003; System architecture is defined, and it will be completed when SASY 2000 prototype will be operational, in summer 2003; Cabling and connectors are defined for the HV distribution, while it has to be completed for links between mainframe and distributors and between primary power supply and distributors; Cabling and connectors are defined for the HV distribution, while it has to be completed for links between mainframe and distributors and between primary power supply and distributors; Cooling needs more development in order to be designed; Cooling needs more development in order to be designed; Rad – hard qualification is on the way; Rad – hard qualification is on the way; Electrical noise should be reduced by a factor of 2 by means of better screening; Electrical noise should be reduced by a factor of 2 by means of better screening; Hardware and software interface are fully developed. Custom applications are in development, using H8 as laboratory; Hardware and software interface are fully developed. Custom applications are in development, using H8 as laboratory; Tenders will start within Pre-series production is expected to be ready for end 2004, in time for beginning MDT installation. Final production will terminate beginning Tenders will start within Pre-series production is expected to be ready for end 2004, in time for beginning MDT installation. Final production will terminate beginning Budget availability is a real issue. Total cost seems higher than what foreseen in Core 7. At present, it is too early for a well defined cost estimate. Budget availability is a real issue. Total cost seems higher than what foreseen in Core 7. At present, it is too early for a well defined cost estimate.