The effect of humidity on reverse breakdown in 3D silicon sensors McDuff, H.; Hoeferkamp, M.R.; Seidel, S. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
06/2015, Volume:
785, Issue:
C
Journal Article
Peer reviewed
Open access
The effect of humidity on reverse breakdown in silicon sensors of the “3D” geometry is studied for unirradiated and irradiated samples exposed to fluences relevant to the environment of the High ...Luminosity Large Hadron Collider. Leakage currents are measured and breakdown voltages are compared for a range of relative humidities and bias voltages. The proton beam at LANSCE, Los Alamos National Laboratory, was used to irradiate samples with 800MeV protons up to 2×1016p/cm2.
Active-edge planar radiation sensors Kenney, C.J.; Segal, J.D.; Westbrook, E. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
09/2006, Volume:
565, Issue:
1
Journal Article
Peer reviewed
Open access
Many systems in medicine, biology, high-energy physics, and astrophysics require large area radiation sensors. In most of these applications, minimizing the amount of dead area or dead material is ...crucial. We have developed a new type of silicon radiation sensor in which the device is active to within a few microns of the mechanical edge. Their perimeter is made by a plasma etcher rather than a diamond saw. Their edges can be defined and also passivated by growing, in an intermediate step, a field oxide on the side surfaces. In this paper, the basic architecture and results from a synchrotron beam test are presented.
Free-electron lasers (FELs) opened a new window on imaging the motion of atoms and molecules. At SLAC, FEL experiments are performed at LCLS using 120 Hz pulses with <inline-formula> <tex-math ...notation="LaTeX">10^{12} </tex-math></inline-formula> to <inline-formula> <tex-math notation="LaTeX">10^{13}~\mathrm {photons} </tex-math></inline-formula> in 10 fs (billions of times brighter than at the most powerful synchrotrons). Concurrently, users and staff operate under high pressure due to flexible and often rapidly changing setups and low tolerance for system malfunction. This extreme detection environment raises unique challenges, from obvious to surprising, and leads to treating detectors as consumables. We discuss in detail the detector damage mechanisms observed in 7 years of operation at LCLS, together with the corresponding damage mitigation strategies and their effectiveness. Main types of damage mechanisms already identified include: (1) x-ray radiation damage (from "catastrophic" to "classical"), (2) direct and indirect damage caused by optical lasers, (3) sample induced damage, (4) vacuum related damage, (5) high-pressure environment. In total, 19 damage mechanisms have been identified. We also present general strategies for reducing damage risk or minimizing the impact of detector damage on the science program. These include availability of replacement parts and skilled operators and also careful planning, incident investigation resulting in updated designs, procedures and operator training.
Stimulated Brillouin scattering (SBS) featuring sub-nanosecond response time takes place at a high power threshold, which enables its application at a high power density. When the intensity of input ...light excesses the SBS threshold, strong SBS process takes place through SBS medium, leading to a quick energy transfer from pump to the Stokes and thereby an optical limiting characteristic in the output energy. In this paper, the correlation between SBS output energy and input power density is numerically simulated and validated in the Nd: YAG Q-switch laser system. The results indicate that not only the output energy exhibits an optical limiting characteristic, but also the clamped value of output energy can be controlled by changing the medium or the focal length.
In order to improve the optical limiting performance based on stimulated Brillouin scattering (SBS), a method based on double SBS is proposed in this paper. The dependence of the output energy of ...optical limiting based on double SBS on the pump energy is numerically simulated, and experimentally validated with an Nd:YAG seed-injected laser. The results indicate that only the first SBS optical limiting works in the case of low pump energy. However, as the pump energy increases, the second SBS process can be activated if the transmitted power of the first SBS is still above the SBS threshold. Therefore, the output energy characteristic of optical limiting based on double SBS is much better than that based on single SBS. Owing to the sub-nanosecond response time and a high power threshold, the SBS optical limiting can provide protection in high power laser systems.
A method of generating a flat-top waveform in the time domain based on stimulated Brillouin scattering (SBS) is proposed. The transmitted pulses are simulated with pump wavelength at 1064 nm and ...532 nm, respectively, and validated in the experiment performed with the Nd:YAG seed-injected laser. The experimental results agree well with the theoretical simulation. With 532 nm pump wavelength, the top of the transmitted pulse is almost a platform, while there is a peak in the front and a platform in the back with 1064 nm pump wavelength. The mechanism behind the generation of flat-top waveform with 532 nm pump wavelength is analyzed in details.
Since it began operations in 2009, the Linac Coherent Light Source (LCLS) has opened a new and dynamic frontier in terms of light sources and their associated science 1, 2. An increase in brightness ...by a factor of a billion over pre-existing synchrotrons, in combination with ultra-brief pulses of coherent X-rays, is ushering in a new era in the photon sciences. Pulses with durations of 50 fs under standard conditions and below 10 fs with a reduced energy per bunch are possible. Over 1013 or 1012 X-rays per pulse can be generated at the upper and lower ends of the X-ray energy range of 285 eV to 9600 eV. One of the unique machine parameters is its strobe-like time structure, where single ultra-brief pulses are delivered at a repetition rate of 120 Hz. The above characteristics represent a singular environment in which to operate detectors and demand the development of a new class of high-frame-rate camera systems. PUBLICATION ABSTRACT
3D silicon detectors—status and applications DaVia, C.; Hasi, J.; Kenney, C. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
09/2005, Volume:
549, Issue:
1
Journal Article
Peer reviewed
3D silicon technology is a new way to make silicon detectors using Micro-Electro-Mechanical-Systems (MEMS) processing. In this innovative design the electrodes penetrate through the silicon bulk ...perpendicular to the surface. Two types of device have been developed—3D and planar 3D. Both use an edge electrode that eliminates the need for guard rings and provides sensitivity to within a few microns of the edge. 3D technology and its advantages are reviewed and examples of the two types of device are shown.