一種真空熒光屏的可靠性分析
作者:覃曉瓊,師義民,李豪亮…
摘要:基于真空熒光屏(VFD)壽命服從對(duì)數(shù)正態(tài)分布的條件,本文在逐次定數(shù)截尾樣本下研究了VFD的平均壽命、失效率和可靠度的點(diǎn)估計(jì)及其置信下限,并利用Monte-Carlo方法對(duì)估計(jì)結(jié)果的優(yōu)劣進(jìn)行了分析比較,驗(yàn)證了結(jié)論的正確性和可行性.
關(guān)鍵詞:真空熒光屏 對(duì)數(shù)正態(tài)分布 逐次定數(shù)截尾 可靠性評(píng)估 平均壽命 置信下限 可靠度 點(diǎn)估計(jì) 極大似然估計(jì) 失效率
Beam Imaging Solutions (BIS)?introduces the new 90-degree BOS which allows remote imaging of a beam at 90 degrees to the imaging plane. Like the BOS-18-IW and BOS-40-IW, the new BOS-75-IW can be attached to a linear motion feedthrough and placed into and out of the beam allowing for remote imaging, deep within the vacuum chamber. The imaging is accomplished by mounting a standard BOS MCP/phosphor screen stack onto a metal housing which has a mirror mounted at 90-degrees with respect to the imaging plane. The housing is wedged shaped to minimize the physical size of the imager, and has convenient points for attaching to a linear motion feedthrough. Electrical connections are made by attaching flexible electrically insulated wires to a connection block on the wedge from an electrical feedthrough. In their standard form, the BOS-IW units are available with the MCP/phosphor assembly mounted to wedge shaped housing with electrical connection block. BOS-IW kits are also available, and include the BOS-IW unit with electrical feedthrough, viewport, linear motion feedthrough and camera systems.
Imaging Area:
- 75mm Diameter
MCP: (Standard)
- 3.410″ Diam. (BOS-75), 25 micron channel diameter, Detection or Imaging Grade
- 75mm active area, 32 micron pitch, 8° Bias Angle, 40:1 Aspect Ratio (Standard, BOS-75)
- Min. Gain:? 1 x 10^4 (single plate, Std.) 1000V? > 107 (chevron, OPT-01), 2000V
Phosphor Screen (Standard)
- P-43 with aluminum overcoat. P-43 Peak Wavelength: λ= 545 nm.
Construction Materials
- Housing: Aluminum (Std.) 304 Stainless is optional
- Electrical Connection Block: ULTEM 1000
- Mirror: 125mm (W) x 150mm (L) x 3mm (T), 2 waves per inch flatness, B270 Glass, Index=1.523
Power Supply Requirements:
- 0 – + 1000V, 1mA single MCP (Standard)
- 0 – + 2000V, 1mA dual MCP (OPT-01)
- 0 – + 5000V, 1 mA Phosphor Screen
Beam Energy Range:
- 1 eV to over 50 keV
Beam Current Range:
- < 10 μA (with optional beam attenuation grids)
Vacuum:
- 1 x 10-6 Torr or better required to operate MCP
- UHV compatible, maximum bakeout temperature 300 C