|The heating shield is installed on the goniometer head between the
sample and the phi axis. It protects the phi axis from
over cooling and ice formation. The heating shield has
a cone shape for reduction of turbulence and contains
a thermocouple which is used to regulate the
Replacing the Shield
||If the heating shield becomes covered with ice, you may need to
install the replacement heating shield which is located on the tool
board. First loosen the tiny screw on the goniometer head, which may
be accessed through a small hole in the heat shield as shown
below. Then you can remove the shaft from the goniometer
head. Remember to tighten the screw when finished installing both
In order for the heating shield to rotate freely, a washer must be installed on both sides of the bearing. The washers should be installed so that the thinner side of the washer is pushing on the inner radius of the bearing.
Heating Shield Design
The heating shield has a cone shaped body with a heating element
attached to it from the inner side. A ball bearing is installed in the
top of the cone. This bearing facilitates shield rotation on the
goniometer head shaft. A thermocouple is attached to the side wall of
the shield. The reading from the thermocouple is used to keep the
shield temperature approximately the same independent of the presence
and the strength of the cryo-stream. The wire leads to the
thermocouple and the heating element pass through the side wall of the
The latest design revision includes replacement of the nichrome
wire heating element with a printed-circuit heating element on a
flexible capton-aluminum substrate and additional protection of the
wire leads with an aluminum wire guide tube attached to the side wall
of the shield. See Assembly
Diagram for details.
Complete part list for the heating shield includes:
- Heating Shield Body. Drawing.
- Wire Guide. Drawing.
- Heating element. Drawing. Producer: MINCO Products, Inc. p: 763-571-3121, f: 763-586-2988. Part #: HK22765. SLAC PO.#: 18148.
- Ball Bearing. Part #: A 7Y 5MFSS1006. Producer: Sterling Instrument. p: 516-383-3300. f: 516-326-8827. Supplier: Western Components, p: 650-594-1222.
- Thermocouple copper/constantan, teflon ins. Part #: 5TC-TT-T-30-72. Diam: 0.01". Producer: Omega Engineering, Inc. p: 203-359-7874, f: 203-359-7700.
- 4-pin connector, metal, male plug, circular, Trim-Trio system. Part #: G6B104PNE. SLAC store cat.# 59-299-206-01, item # 046400.
- 4 Pin Contacts, solid, machined, size 16. Trim-Trio system. Part # RM24M-9D28. SLAC store cat.# 59-299-801-12, item # 048500.
- Heat shrinking tube, 1/4" dia.
- Thermoconductive compound ECCOBOND 285 and Catalyst 9 (curing agent). Producer: Emerson & Cuming, Inc. Supplier: E.V.Roberts. Tel: (800) 374-3872 - Ext.1 Fax: (310) 839-9427
For further information see Heat Shield Assembly - Illustrated Guide.