Proto DUNE SP Coldbox APA 1 APA 2
Proto. DUNE SP Coldbox APA 1, APA 2 Test Giovanna Lehmann – Xavier Pons CERN 18/01/2018 1
During the Coldbox assembly, 7 PT 100 were installed inside the coldbox as gradient monitor in a support plate. PT 100 commercial type The 7 PT 100 x 4 wires were connected On top of the coldbox in a flange with Sub-D 50 pin connector Outside flange Wire CERN stock type PTFE unshielded AXON 4 Quad twisted wires reference 4 E 2807^BDHL inside flange 2
1 st APA TEST DCS Readout based on SIEMENS PLC S 7 -1500 PT-100 Analogue input module ± 0. 1 C precision Coldbox DCS Rack Back side PLC 6 U Crate – Field Interface 48 Burndy connector connected to detector ground and cable shield 3
APA 1 Test - Coldbox Temperature Cable Details CERN MCA 50 – 25 twisted pair shielded cable To be used in the final system MCA 26 13 twisted pair shielded cable 4
FFT spectrum Coldbox Noise research and clean. (From Jake Calcutt on 25/10/2017) 5
APA 1 Test – From DCS side the APA 1 test on December 2017 was OK 6
APA 2 Test – December 2017 / January 2018 It was requested to install 3 additional PT 100 in the APA frame (Top, Middle, Bottom) This was performed with the same configuration as the gradient monitor: same PT 100, same wire, connected to the spare pins/wires in the top flange) But abnormal high noise from 3 APA PT 100 was observed in the Cold Electronics. From Shanshan on 19/12/2017 7
APA 2 Test – December 2017 / January 2018 Several search/clean noise tests were performed In one of these tests the temperature cable was disconnected from the top of the coldbox and the pins of the PT 100 were Shorted to detector ground (coldbox vessel), this test was not done for the APA 1 commissioning. All PT 100 leads connected to detector ground From Shanshan 19/12/2017) 8
Shanshan -proto. DUNE APA integration test results – slide 26 – on 8/01/2018 9
APA 2 Test – January 2018 At the same time the DCS readout test was moved from SIEMENS PLC to CERN-DT Multiplexer board Including: - 7 PT 100 of the gradient - 3 PT 100 of the APA frame 10
APA 2 Test – January 2018 - After several search/clean noise test, it was decided to disconnect the 3 PT 100 connected on the APA frame. They were unsoldered from the inner side of the coldbox flange and all leads shorted to coldbox vessel (Detector Ground) Before disconnecting the 3 APA RTD’s noise After disconnecting the 3 APA RTD’s noise From Geff on 15/01/2018 11
APA 2 Test – January 2018 The cooldown started on 15/01/2018 Without the 3 APA PT 100. Using multiplexing in the DCS readout Disconnected temperature warm cable test 12
(First) DCS conclusions : - The low cost, small, industrial power supplies have to be removed - To prepare the new circuits for the fan and heater control. - Preparing a design of a filter stage to be installed before the flange in order to remove the capacitive coupled noise (with the support of V. Radeka (BNL) - The PT 100 cables have to be shielded, possibility to replace the ones in the coldbox by the Valencia - It’s necessary a good quality of DCS power supply: - 24 VCC for general DCS - 18 VCC for the fans - 10 VCC for the heaters - ± 15 VCC for the temperature multiplexing
- Slides: 13