1. The research on vacuum window of cryogenic receiver
Wang kai

2. 目 录 What is vacuum window？ the samples of vacuum window
The requirement of vacuum window：Sealing、 wave-transparent、Resistance to pressure
the measurement of vacuum window
the fabrication of vacuum window

3. What is vacuum window?

4. S/X dual-band cryogenic receiver
PTFE（聚四氟乙烯）
polyimide film（聚酰亚胺）
Polystyrene foam（聚苯乙烯）

5. XAO 1.3cm band cryogenic receiver
PETP(Polyethylene terephthalate)： MYLAR（聚对苯二甲酸乙二醇酯）, tensile strength ：MD186.2MPa，TD205.8MPa，thiceness:0.188mm, Diameter=125mm, Insertion loss= 0.05dB

6. Broadband cryogenic receiver vacuum window
Broadband：1.2-9GHz, Diameter=500mm，noise=2.5K。
PTFE：0.75mm
polyimide film：150MPa ,3.5±0.4 ,0.075mm ，noise=1K(X-band)
PMI foam： polymethacrylimide（聚甲基丙烯酰亚胺），6.069MPA，
1.12 （f=10GHz），noise＜2K
Nylon材料： polyamide (聚酰胺纤维)

7. 21 cm EFFelsberg 7 beam receiver

8. 21 cm EFFelsberg 7 beam receiver
Ceramic
PTFE(teflon)

9. The requirement of vacuum window：Sealing
ALMA Band-6： GHz, WR-10($1000)
Mylar
Epoxy：Epo-Tek [2] epoxy, a low dielectric constant and loss

10. Sealing

11. Sealing

12. wave-transparent The Q/U Imaging Experiment (QUIET receiver)
19beams Q-band(30-40GHz)，d=266.7mm;90beams W-band(40-90GHz),d=558.8mm
Teflon:n=1.2, Anti-reflection Coating , loss tangent: 2.5×10−4
LDPE:low-density polyethylene(低密度聚乙烯)
UHMW-PE:ultra-high molecular-weight polyethylene（超高分子量聚乙烯），n=1.52，3/8”（0.95CM）
Polystyrene foam：10cm

13. wave-transparent

14. wave-transparent
n（teflon）=1.2±0.07

15. Resistance to pressure
VLBA, Polystyrene foam（聚苯乙烯）
Emerson Eccofoam PS-1.04+EPOXY , 40psi, 6.4 E-8
GHz（L），thickness 2.5”，d = 6.3”；
GHz（S），thickness 1.0”，d = 4.1”；
polyethylene(聚乙烯)+ Eccofoam PS-1.04
NRAO，MYLAR

16. 2000 ALMA, the dielectric constant
60mil ,40 mil, 20 mil RA7956

17. 2000，ALMA，transmission and reflection
QMC100 for Bands 3（ GHz）、 QMC230 for band 6( GHz）
quartz（0.226”）

18. 2000，ALMA，transmission and reflection

19. 2001，ALMA band 3-10
insertion loss＜0.1dB，reflection loss＞20dB

22. GBT 3mm Receiver Quartz Vacuum Window
GBT 3mm(68-116GHz) ,diameter=80mm
Goretex: AR,thickness>0.02”,adhesion epoxy(0.0002”)
HDPE: AR layers,1/16”,adhesion epoxy
Quartz：thickness=0.225” 0.57cm， d=3.75” (9.525CM)

23. the fabrication of vacuum window（3mm）

24. the fabrication of vacuum window（3mm）

25. the fabrication of vacuum window（3mm）

26. the fabrication of vacuum window（3mm）

27. the fabrication of vacuum window（3mm）

28. the fabrication of vacuum window（3mm）