1. DQHDS Upgrade: Status of Hardware Design. Approach to implementation of the new heater measurement system. 08/06/2011V. Froidbise

2. Summary Requirements Principles of measurements Implementation: modifications in situ New DQLPU crate Status 08/06/2011V. Froidbise

3. Requirements 1.Current discharge recording during a quench. 2.Measurement of resistance value of the heaters, periodically. 08/06/2011V. Froidbise

4. 1st principle of current discharge measurement 08/06/2011V. Froidbise Output stage of DQHDS U_HDS Heater + - Shunt

5. 2d principle of current discharge measurement: 08/06/2011V. Froidbise Output stage of DQHDS U_HDS Heater Advantages of the Pulse transformer, called: « Broad-Band Current –Pulse Transformer ». Shielded – Ferrite-Core : Galvanic isolation Maintain of the continuity in the wire Less noisy + -

6. With measurement of resistance value of the heaters 08/06/2011V. Froidbise Output stage of DQHDS U_HDS Heater + - Constraint: create two connections in the discharge circuit + -

7. Principle schematic of current source 08/06/2011V. Froidbise

8. « Crawford box » 08/06/2011V. Froidbise

9. Modifications or design a new connection box? 08/06/2011 V. Froidbise 6 cm8 cm

10. DQLPU 08/06/2011V. Froidbise Power supply DQQDL_A DQQDL_B DQAMC FIP Future Electronics in the DQLPU: New motherboard + commutation Relays DQAMC DQQDL_A DQQDL_B Current sources + heaters measurement Current discharge measurement Lateral heat sink Linear Power Supply Switching Power Supply

11. What is today’s status – and outlook? Tests for DQHDS discharge current through a shunt already validated, but sampling frequency must be adapted. Waiting for a sample of a toroidal pulse transformer before performing tests and validation (Knud). Integration into the existent Crawford box will be envisaged after discussions with RP to see where and what might be done. Reliability of the contact taps needed must be done without weakening of the discharge circuit appropriated connections. Simulation/Measurement of a defect in a heater strip validated in a DC method (see Reiner’s presentation and Joaquim’s tests). Prototype of a precision current source is under tests, looks promising. New developments of 3 electronics cards: a motherboard, a heater resistance measurement board (4 circuits / dipole) and a heater discharge current measurement board. Probably a new crate DQLPU: easier to operate. 08/06/2011V. Froidbise