The research on vacuum window of cryogenic receiver Wang kai 2015-7-9
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
What is vacuum window?
S/X dual-band cryogenic receiver PTFE（聚四氟乙烯） polyimide film（聚酰亚胺） Polystyrene foam（聚苯乙烯）
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
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)
21 cm EFFelsberg 7 beam receiver
21 cm EFFelsberg 7 beam receiver Ceramic PTFE(teflon)
The requirement of vacuum window：Sealing ALMA Band-6：73.7-88.3 GHz, WR-10($1000) Mylar Epoxy：Epo-Tek 301-2 [2] epoxy, a low dielectric constant and loss
Sealing
Sealing
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
wave-transparent
wave-transparent n（teflon）=1.2±0.07
Resistance to pressure VLBA, Polystyrene foam（聚苯乙烯） Emerson Eccofoam PS-1.04+EPOXY , 40psi, 6.4 E-8 1.3-1.8GHz（L），thickness 2.5”，d = 6.3”； 3.0-3.4GHz（S），thickness 1.0”，d = 4.1”； polyethylene(聚乙烯)+ Eccofoam PS-1.04 NRAO，MYLAR
2000 ALMA, the dielectric constant 60mil ,40 mil, 20 mil RA7956
2000，ALMA，transmission and reflection QMC100 for Bands 3（84-116 GHz）、 QMC230 for band 6(211-275 GHz） quartz（0.226”）
2000，ALMA，transmission and reflection
2001，ALMA band 3-10 insertion loss＜0.1dB，reflection loss＞20dB
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)
the fabrication of vacuum window（3mm）
the fabrication of vacuum window（3mm）
the fabrication of vacuum window（3mm）
the fabrication of vacuum window（3mm）
the fabrication of vacuum window（3mm）
the fabrication of vacuum window（3mm）