background: the aim of this work was to study the output factors for linac using different ionization chambers and build up caps. materials and methods: output factors were measured for open square fields (3 × 3 cm to 40 × 40 cm) defined by collimator jaws for 6 and 15 mv photon beams from a varian clinac 2100c accelerator were measured. the measurements in air were performed using compact cyli...

Reduced flow rate electrospray ionization has been proven to provide improved sensitivity, less background noise, and improved limits of detections for ESI-MS analysis. Miniaturizing the ESI source from conventional electrospray to microelectrospray and further down to nanoelectrospray has resulted in higher and higher sensitivity; however, when effects of flow rate were investigated for atmosp...

-Two parallel-plate ionization chambers were projected, constructed and evauated for use in high energy electron beams. They were constructed using the two plastic materials recommended for clinical dosimetry protocols, i.e. acrylic and polystyrene. Both chambers have cylindrical shape with entrance windows in aluminized Mylar and they are open to the air. The acrylic chamber has a 2 mm air gap...

We demonstrate anomalous gaseous field ionization and field desorption on branching intrinsic silicon nanowires grown by a two-step VLS technique. Field ionization and desorption I-V curves of argon, nitrogen, helium, and ammonia, were recorded individually within a wide pressure range (10 to 10 Torr). Field ionization initiated at sub volt was followed by field desorption at about 7 – 38 V (ap...