The goal of this study was to investigate small field output factors (OFs) for flat-tening filter-free (FFF) beams on a dedicated stereotactic linear accelerator-based system. From this data, the collimator exchange effect was quantified, and detector-specific correction factors were generated. Output factors for 16 jaw-collimated small fields (from 0.5 to 2 cm) were measured using five differe...

We have developed two radiation-hard ASICs for optical data transmission in the ATLAS pixel detector at the LHC at CERN: a driver chip for a Vertical Cavity Surface Emitting Laser (VCSEL) diode for 80 Mbit/s data transmission from the detector, and a Bi-Phase Mark decoder chip to recover the control data and 40 MHz clock received optically by a PIN diode. We have successfully implemented both A...

The dynamic range and error performance of the diode power detector used to denormalise the digital correlations in interferometric radiometers is analysed by means of a second-order model of the diode response. This gives an easy method to establish system dynamic range as a trade-off between both the error contribution of measurement uncertainty and diode nonlinearity. The method is illustrat...

We report the successful development of hybrid PIN diode arrays and a series of room-temperature measurements in a high-energy pion beam at FNAL. A PMOS VLSI 256 x 256 readout array having 30 pm square pixels was indiumbump bonded to a mating PIN diode detector array. Preliminary measurements on the resulting hybrid show excellent signal-to-noise at room temperature.

A small, easily-built photometer is described, in which a solid-state light-emitting diode is used as the light source and a phototransistor as the detector. The detector response is kept constant by modulating the diode intensity in proportion to the absorption characteristics of the sample being analyzed. Linearity and stability are good, even with turbid solutions (drift is <0.00 1 absorbanc...

The AAPM Task Group 40 reported that in vivo dosimetry can be used to identify major deviations in treatment delivery in radiation therapy. In this paper, we investigate the feasibility of using one single diode to perform in vivo dosimetry in the entire radiotherapeutic energy range regardless of its intrinsic buildup material. The only requirement on diode selection would be to choose a diode...