It consists of a sealed air-filled cylinder called an ionization chamber. This is much the same as an ionization chamber in particle physics. It is the isotope used in an americium smoke detector based on an ionization chamber. It then escapes into the ionization chamber through a pinhole. A Sievert chamber is a type of ionization chamber used in radiation dose measurements. A wide range of ionization chamber, film badge, and thermoluminescent personal dosimeters are available. Figure 7 shows the Gas Ionization chamber with Isobutane as the detector gas. Similar to the CD V-715, the CD V-720 is a fixed-position ionization chamber survey meter. The radioactive decay can be detected through an ionization chamber or autoradiographs of gels. The ionization chamber has found wide and beneficial use in smoke detectors. The dosimeter was a miniature ionization chamber, charged with 170 volts. An ionization chamber with full track reconstruction capabilities for studying reactions of astrophysical importance.