Polycrystalline Graphite Foils (Flexible PCGs)
About PCG Foils
Polycrystalline Graphite (PCG) foils made by ACF-Metals are typically used as extractor (stripper) foils in accelerators. They are as efficient as amorphous carbon foils of the same areal density and have in-beam lifetimes competitive with arc-evaporated foils.
PCG's are also used as windows between regions of different vacuum and to transmit synchrotron radiation at power densities up to 500 watts per square centimeter, as well as to strip uranium beams at energies of 50 MeV per nucleon.
Our in-house technical team is prepared to answer questions and provide ideas and feedback regarding your application.
Greater areal density, easier to handle, and less expensive!
PCG foils have several advantages over standard arc-evaporated foils in that they can be produced to higher areal densities, they are easier to handle, and at areal densities greater than 400µg/sq.cm they are less expensive.
Standard polycrystalline graphite foils, 25mm X 60mm, are freestanding and shipped in individual protective containers. Foils are also provided in custom "cut sizes" that are ready for immediate mounting on the support of your choice. PCG foils have no known limit to their shelf life.
Technical Information
The product number (ie: PCG-400 or PCG-1000) gives the carbon areal density in micrograms per square centimeter. The equivalent thickness is the geometrical thickness that the foil would have at that areal density if the mass density were 2.00g/cc. These foils have nominal mass density 1.0 +/-0.1g/cc.
Standard PCG foils are available from stock. They are categorized by their areal density, with minimal variation (+/- 15%). Tighter tolerances are available by quote. The areal density of our foils is also referred to as surface density, specific density, or mass per unit area. Every foil is measured, weighed, and assessed in order to maximize accuracy and quality. Please see the ACF-Metals' "Product Information" for more properties of these foils, especially for information regarding flatness, smoothness, and light-tightness.
Quantity discounts are available on single shipments of carbon foils of the same size and areal density: 5% (quantity of 100+) or 10% (quantity of 1000+). Please contact ACF-Metals directly to place orders that would involve this discount.
Please request a FREE COPY of our PRODUCT INFORMATION, for elaboration on the above highlights and for additional helpful information!
Technical Information
Areal Density
Standard foils are regularly available from stock. They are categorized by their areal density, with minimal variation (+/- 10% or +/- 0.2µg/sq.cm for the thinnest foils). Tighter tolerances are available by quote. The areal density of our foils, also known as surface density, specific density, or mass per unit area, is in units of micrograms per square centimeter. Foils are measured optically and/or by weighing in order to maximize accuracy. Please see the ACF-Metals' "Product Information" for more properties of these foils, especially for information regarding flatness, smoothness, and light-tightness.
Collodion Option
Foils below 5.0µg/sq.cm may be difficult to mount over apertures larger than a few mm in diameter. When requested, ACF-Metals will add an additional coating of collodion on one side of the carbon foil. This provides additional support for the foil, and for some users, a longer foil lifetime.
Light Tightness
In order to minimize issues associated with naturally occurring pinholes, some investigators will use multiple layers of carbon foils. Light tightness may be particularly important when foils are used as optical filters, neutralizer foils, and windows for low-pressure gas-cell targets. ACF-Metals offers layered carbon foils in certain thicknesses. Note: Pinholes are observed to form spontaneously in hybrid type boron-carbon foils at temperatures above 1800 K, another reason why ACF-Metals does not offer hybrid foils.
Additional Savings
Quantity discounts are available on single shipments of carbon foils of the same size and areal density: 5% (quantity of 100+) or 10% (quantity of 1000+). Please contact ACF-Metals directly to place orders that would involve this discount.
Please request a FREE COPY of our PRODUCT INFORMATION, for elaboration on the above highlights and for additional helpful information!