1. Presentazione delle richieste immediate per l’upgrade di MEG (gruppo di Roma) Cecilia Voena Mar 15 th, 2013

2. Rome hardware commitments for the DC HV system Cabling Target placement and movement (in collaboration with PSI)

3. Rome hardware commitments for the prototypes The plan is to build the prototypes in 2013 to drive the choice of the solution for the final DC -HV custom system -Control system for the wire tension - Gas system

4. HV custom system

5. HV system for the final chamber Cylindrical DC 1.8m long Geometry is still under study - 1500-2000 wires to be supplied HV segmentation (number of HV channels) - to be decided (expected drawn current: 1μA for inner wires, 0.1μA for outer) - “natural” segmentation, following FE segmentation: order of 60 HV channels

6. Requirements Noise <= few mV at signal output - Fourier spectrum is relevant Fast trip capability Operational stability Current monitor sensitivity Sensitivity to radiation and magnetic field - If we have PS outside the detector probably is not an issue - If we have everything on endplates it should be checked (like DC-DC converter see later) Commercial or custom?

7. HV system for the prototype 5 layers One HV channel for each layer + some HV channels for guard cells + some HV channels to study individual cells =>18 HV channels We have an agreement with CAEN, they will rent us a demo for the board they proposed Lecce developed a test board for the 3-tube based on an HVN DC-DC converter. We would like to develop a prototype based on this

8. DC-DC converter based board Based on HVM DC-DC converter A controller has been developed by Lecce with 3 channel and will be tested with the 3-tube. Then it will be sent to Rome for further tests and engineering work Crucial test is magnetic field test M.Panareo

9. HV custom system: costs Board with 1 HV channel (6 wires) - DC-DC converter 140€ (with an order of 10) - PCB: 50€ - Microcontroller: 10€ - other components: 20€ TOTAL = 220€ x 18 => 5k€ (including IVA)

10. System for measuring wire tension

11. Methods Induced mechanical oscillation with pulse of current on wires while immersed in B field (e.g. Babar) Induced mechanical oscillation applying alternating HV (order of 1kV ) (e.g. Kloe) Acoustical method - sound burst induces current signal due to change of capacitance - Advantages: no magnetic field needed to be turned on no HV needed to be applied to the wire - We would like to have the capability to measure many wires at a time - This could be used also for the final chamber

12. Acoustical method Short sound burst induced with a PC speaker Method proven for a BTeV straw tube for tensions in the range 20-100gr Error on frequency~5Hz (=2gr)

13. Acoustical method: costs Sound generator: 300€ labview licence: available at INFN Roma Computer woofer: 100€ Commercial op-amp amplifier: 50€ NI DAQ board: 3k€ miscellanea: 500€ (supports..) ====TOTAL==== 4kE

14. Note: we are reconsidering the sharing of commitments with PSI. They will contribute more on the mechanics (e.g. coupling to COBRA) and INFN will contribute to the gas system We would like to setup a system to make practice (with components that will be reused on the final system) Gas system

15. Requirements: two gas lines plus one spare Components (iva included) : - controller (4 ch): 6k€ - 3 mass flowmeters: 6k€ - linear valve+controller: 5k€ - miscellanea: 3k€ P and T sensors for each line: O 2 and H 2 O analyzer, gas pipes,swagelok, pressure reductos ====TOTAL=== 20kE

16. Summary of requests HV custom system: 5k€ Control system for the wire tension:4k€ Gas system: 20k€