Outline 1 Measures to improve TTS 2 Measures

Outline 1. Measures to improve TTS 2. Measures to improve delayed pulses 3. Measures to improve QE 4. Flying leads straight to the electronic base 5. Upgrade of the electronic base

1. Measures to improve TTS

One important reason of the worse TTS reported in Feb. 2017 — Low HV 1300 Test result in June 2016: Average HV(as HV 1) of 6 tubes: 1155 V. Average TTS of 6 tubes is 3. 92 ns. 1200 1100 1000 900 800 0 1 2 3 4 5 6 7 1300 Test result in Feb. 2017: Average HV (as HV 2) of 40 tubes: 994 V. Average TTS of 40 tubes is 4. 85 ns. 1200 1100 1000 900 800 0 5 10 15 20 25 30 35 40 45 HV 1 - HV 2= 1155 V - 994 V = 161 V TTS is a function of HV. The TTS value will decrease when HV

Optimize the assembly clamp Tilted structure will make a worse TTS, so we optimized the assembly clamp to improve the assembly accuracy.

Summarize TTS: ① The low HV voltages and the tilted structure were the root causes of worse TTS with the December 2016 deliveries to KM 3 Ne. T. ② The tilted structure was introduced when changing the 20 pins connection to the 18 flying leads connection in 2016, which affected the centralisation of the structure inside the bulb. ③ HZC has made an optimisation to the assembly clamp and other calibres to control the shape, the height and the centralisation of the structure. ④ With higher HV (average voltage should be around 1150 V) and improved centralisation of the structure, the average TTS of XP 82 B 2 F will be around 4 ns.

Test result No. 1: Tube SN. : 323 HV: 1167 V TTS= 65. 74*2. 354*25/1000 ns= 3. 87 ns

Test result No. 2: Tube SN. : 335 HV: 997 V TTS=70. 16*2. 354*25/1000 ns= 4. 13 n

Test result No. 3: Tube SN. : 320 HV: 1248 V TTS=58. 09*2. 354*25/1000 ns=3. 42 ns

2. Measures to improve delayed pulses The major measures to improve the delayed pulses (15 -60 ns) is to increase the vacuum level inside the tube. HZC has made new tubes under the condition of high level vacuum in the process. The below measured values prove that the level of delayed pulses meet the requirement of KM 3 Ne. T again, as with the delivery in June 2016. Tubes made in 2016: Tube SN: 170 delayed pulses: 3. 24% Tubes made in March 2017: Tube SN: 296 delayed pulses: 2. 87% Tube SN: 326 delayed pulses: 2. 87%

Picture of delayed pulses testing

3. Measures to improve QE Plan: ① To decrease DCR by HZC in March 2017; ② To improve QE (mainly at 404 nm) with PHOTONIS in April 2017.

4. Flying Leads straight to electr. base • No more bending is required and the risk of glass crack is avoided.

5. Upgrade electronic base March 27, 2017: HZC has shipped 15 sets of newly upgraded electronic bases to Mr. Paul Timmer for the final choice and acceptance of the configuration. 3 configurations of electronic base, 5 sets for each configuration. The only differences between the 3 configurations concern the windings (N 1: N 2) of the transformers and the transformerclamps, to achieve a proper inductance. See next sheets.

Transformer C N 1: N 2=15: 111 With new-design clamp

Transformer D N 1: N 2=14: 103 With new-design clamp

Transformer A N 1: N 2=16: 118 With old-design clamp

Thanks