1. Basic characteristic of １００ μ ｍＧＥＭ K,Kadomatsu （ saga.u) 池野正弘、宇野彰二、内田智久、氏家宣彦、関本美智子、 田中秀治、田中真伸、仲吉一男、村上武（ KEK) 青座篤史、杉山晃（佐賀大） 中野英一、中川伸介（大阪市大） 杉山史憲（東京理科大）

2. Motivation To understand a basic characteristic of 100  mGEM. We inspect that 100  mGEM can provide higher gain than 50  mGEM. We want to get high gain

3. GEM Foil 140 μm φ = 70μm 50 μm 5 μm Cu Polyimide 10cm Scienergy Co., Ltd. 製 100μm 8 μm Cu Polyimide

4. 100  m-GEM1 Drift Plate 2 ｍｍ E D =0.75kv/cm E I =7kv/cm Single 100mm-GEM Test Chamber 2 ｍｍ Drift Area→E D Induction Area →E I GAS Ar-CO 2 (70/30) 2200pF Read out 55 Fe (5.9 keV X-ray) PCB 1mm □15mm×15mm 36 ＝ 6×6 PCB

5. We normalize ΔV GEM of 100μmGEM to Δ V GEM of 50μmGEM Higher Gain is obtained with 100μmGEM もう少し、高い電圧 を掛けれるようにし たい Single GEM Δ Ｖ ＧＥＭ

6. Single GEM E D dependence ΔV GEM =660V E I =6.0kV/cm E hole =61.9kV/cm ΔV GEM =660V E I =6.0kV/cm E hole =61.9kV/cm 100  mGEM ΔV GEM =350V E I =7.0kV/cm E hole =47.5kV/cm ΔV GEM =350V E I =7.0kV/cm E hole =47.5kV/cm 50  mGEM ・  測定 ・

7. Single GEM E I dependence ΔV GEM =660V E D =0.76kV/cm E hole =61.9kV/cm ΔV GEM =660V E D =0.76kV/cm E hole =61.9kV/cm 100  mGEM ΔV GEM =350V E D =0.5kV/cm E hole =47.5kV/cm ΔV GEM =350V E D =0.5kV/cm E hole =47.5kV/cm 50  mGEM ・  測定

8. E I dependence High Electric field E D =0.75kV/cm ΔV GEM =640V E D =0.75kV/cm ΔV GEM =640V E D =0.75kV/cm ΔV GEM =620V E D =0.75kV/cm ΔV GEM =620V E D =0.75kV/cm ΔV GEM =660V E D =0.75kV/cm ΔV GEM =660V

9. Double GEM Test Chamber 2.0 mm Induction Drift Transfer 7.0kV/cm 0.75kV/cm ETET

10. Double GEM, 100μm E T dependence ΔV GEM =500V E D =0.75kV/cm E I =7.0kV/cm ΔV GEM =500V E D =0.75kV/cm E I =7.0kV/cm

11. Double GEM ΔV ＧＥＭ We were not able to apply the high voltage to ΔV GEM 高 Gain を得たい

12. Now Electric field @ Hole center – １００ μ ｍＧＥＭ：６１．９ kV/cm (Maxwell 3D) – ５０ μ ｍＧＥＭ：４７．５ kV/cm (Maxwell 3D) Single GEM Max high Voltage→Δ V GEM :660V Double GEM Max high Voltage→ Δ V GEM :540V –It is easy to discharge in Double GEM. The second layer GEM discharges due to large number of electrons produced at the First layer GEM

13. Ｗｅ change a diameter of GEM hole. 70μ ｍ φ→ ９０ μ ｍ φ 100μGEM （ 90φ ） Drift Plate （ Mesh ） ２ｍｍ

14. Single GEM Δ Ｖ ＧＥＭ E D =1.5kV/cm E I =6.0kV/cm E hole =61.9kV/cm E D =1.5kV/cm E I =6.0kV/cm E hole =61.9kV/cm 70Φ ED=1.5kV/cm E I =6.0kV/cm E hole =58.0kV/cm ED=1.5kV/cm E I =6.0kV/cm E hole =58.0kV/cm 90Φ

15. E D dependence 90Φ VS 70Φ ΔV GEM =660V E I =6.0kV/cm E hole =61.9kV/cm ΔV GEM =660V E I =6.0kV/cm E hole =61.9kV/cm 70Φ ΔV GEM =660V E I =6.0kV/cm E hole =58.0kV/cm ΔV GEM =660V E I =6.0kV/cm E hole =58.0kV/cm 90Φ

16. E I dependence 90Φ VS 70Φ ΔV GEM =660V E D =0.76kV/cm E hole =61.9kV/cm ΔV GEM =660V E D =0.76kV/cm E hole =61.9kV/cm 70Φ ΔV GEM =660V E D =0.76kV/cm E hole =58.0kV/cm ΔV GEM =660V E D =0.76kV/cm E hole =58.0kV/cm 90Φ

17. Summary 100μmGEM –We have measured the basic characteristic. A Higher Gain can be got with 100  m-Single GEM than that with 50  m-Double GEM. But the gain is not so high as that with 50  m-Triple GEM –A diameter of a GEM hole. We changed a diameter of a GEM hole to 90μm φ from 70μm φ –We can apply higher ΔV GEM. –We can get 2times larger gain. Electric field @ Hole center – ７０ μ ｍ φ ：６１．９ kV/cm – ９０ μ ｍ φ ：５８．０ kV/cm

18. Recycle GEM We try to revitalize the GEM which discharges. Dead GEM Normal Damaged There is burnt area Zoom

19. Soft etching １～３％の塩酸 水溶液に浸ける ５０ｃｍ / 分のスピードでエッジングされる エッジング マシン ８０℃で６時間 乾燥 東海電子工業株式会社の方で エッジングを行った。

20. Reprocessing Soft etching –Etching time is shorter than usual chemical etching. Plasma etching –An etching effect is stronger than chemical etching. –Dead GEMs, which can not be recovered by soft etching, are regenerated by Plasma etching. Recovery of GEM is basically possible About 90% of Dead GEMs can be recovered by Soft or Plasma etching.

21. 10000 1000 100 10 250 300 350 400 450 500 550 600 650 700 750 ΔVgem こちらを見てください

22. ΔVgem=660V Ei=6.0kv/cm E D dependence 90Φ VS 70Φ

23. Ed=1.5kv/cm ΔVgem=660V E I dependence 90Φ,V,S 70Φ

24. ＥＤＥＤ ΔV GEM =660V E I =6.0kV/cm E hole =61.9kV/cm ΔV GEM =660V E I =6.0kV/cm E hole =61.9kV/cm 100  mGEM ΔV GEM =350V E I =7.0kV/cm E hole =47.5kV/cm ΔV GEM =350V E I =7.0kV/cm E hole =47.5kV/cm 50  mGEM

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