PRI Reverse View LEED Optics Models RVL 8-120 M1 & M2

Reverse View LEED Optics, Retractable

Models RVL 8-120 M1 & M2

These eight-inch flange models feature a unique design that ensures reliable, jam-free operation even after many bake-outs. The M1 unit can retract up to one inch from the normal operating position. The M2 unit can retract up to two inches. Three synchronised linear feedthrus mounted on the flange are used to insert and retract the optics. Only three bearings are used on the vacuum side (one for each feedthru). Contact us for an outline drawing showing dimensions and clearances.

Electron Gun:
Beam Diameter	Less than 1 mm at sample
Beam Current	Up to 1µA
Beam Voltage	0 to 3000V
Materials	304 SST and Al₃O₂
Filament	Long life thoriated Iridium hairpin, easily replaceable
Mounting	Gun assembly removable as a single unit
Diameter	15.9 mm OD for minimal collector screen obstruction

Grids:
Number of Grids	Four
Material	Hard Chrome-plated 304SST; 40 lines/cm
Transmission	83% per grid
Mesh Orientation	Aligned to minimize Moiré effects
Geometry	Strong and resilient; may be cleaned if necessary. Grids and collector screen are epicentric

Collector Screen:
Material	Ground optical quality Pyrex glass, coated with SnO₂ and phosphor
Mounting	Special design avoids thermal stresses during bake out, and minimizes chance of damage from mechanical shock
Phosphor	P2 is standard, others available. Durable SnO₂ coating allows recoating with phosphor

Optics Assembly:
Mounting	Complete unit mounted on 8" OD knife edge flange.
Insertion Length, M1	8 inches (flange face to sample) fully inserted
Insertion Length, M2	9 inches (flange face to sample) fully inserted
Sample Clearance	.75 inches from forward end of shield
Viewport	Integral 4" viewport
Shield	Mu metal shield standard, stainless steel available
Electrical Connections	Bakeable MHV feedthrus on mounting flange
Viewing Aperture	96º viewed from either front or back

Electronics:

Compatible with Model 11-020 LEED Electronics.

Options & Modifications:

An insertion length of ten inches is also available. Longer insertion lengths are possible but not recommended.