aperture

The effect of transport apertures on relay-imaged, sharp-edged laser profiles in photoinjectors and the impact on electron beam properties

In a photoinjector electron source, the initial transverse electron bunch properties are determined by the spatial properties of the laser beam on the photocathode. Spatial shaping of the laser is commonly achieved by relay imaging an illuminated circular mask onto the photocathode. However, the Gibbs phenomenon shows that recreating the sharp edge and discontinuity of the cut profile at the mask on the cathode is not possible with an optical relay of finite aperture. Furthermore, the practical injection of the laser into the photoinjector results in the beam passing through small or asymmetrically positioned apertures. This work uses wavefront propagation to show how the transport apertures cause ripple structures to appear in the transverse laser profile even when effectively the full laser power is transmitted. The impact of these structures on the propagated electron bunch has also been studied with electron bunches of high and low charge density. With high charge density, the ripples in the initial charge distribution rapidly wash-out through space charge effects. However, for bunches with low charge density, the ripples can persist through the bunch transport. Although statistical properties of the electron bunch in the cases studied are not greatly affected, there is the potential for the distorted electron bunch to negatively impact machine performance. Therefore, these effects should be considered in the design phase of accelerators using photoinjectors.




aperture

Stuck with Apple’s Aperture? Adobe will give you a hand

After the announcement that Apple will not be continuing development of Aperture, Adobe announces the development of a migration tool to help those thinking about switching.




aperture

iPhone 18 Pro's main camera could have a variable aperture lens

Variable aperture lenses have been present on some Android flagship phones for some time now. #variableaperture #iphone18 #apple



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aperture

iPhone 18 Pro rumored to gain a variable aperture wide-angle lens

In a major update to the camera system, analyst Ming-Chi Kuo says the iPhone 18 Pro's wide angle lens will be upgraded to have a variable aperture.


Apple may update the iPhone's wide-angle lens to give it a variable aperture

Rumors concerning the cameras in the forthcoming iPhone 17 range and later have previously varied from saying they will get better bokeh, to how the front camera's resolution will double to 24MP. Now analyst Ming-Chi Kuo claims to have specific information that the iPhone 18 Pro will gain this variable aperture update.

In a blog post that he says is based on his own industry sources, Kuo says that this update will "significantly improve the user's photography experience."


Rumor Score: ???? Possible


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aperture

Magnum/Aperture Square Print sale

This year’s Magnum Photos and Aperture Square Print Sale, entitled Hidden, is underway right now. For $100, you can get a 6×6-inch museum-quality print from one of 120 modern and contemporary photographers, including Elliott Erwitt, Elinor Carucci, Joel Meyerowitz, Todd Hido and many more. Most of the photos offered are signed by the photographer; others—from […]

The post Magnum/Aperture Square Print sale appeared first on Complete Digital Photography.




aperture

Method and apparatus for making an apertured web

A method for making apertures in a web comprising providing a precursor web material; providing a pair of counter-rotating, intermeshing rollers, wherein a first roller comprises circumferentially-extending ridges and grooves, and a second roller comprises teeth being tapered from a base and a tip, the teeth being joined to the second roller at the base, the base of the tooth having a cross-sectional length dimension greater than a cross-sectional width dimension; and moving the web material through a nip of the counter-rotating, intermeshing rollers; wherein apertures are formed in the precursor web material as the teeth on one of the rollers intermesh with grooves on the other of the rollers.




aperture

Uplink grouping and aperture apparatus

A method includes selecting a subset k of N accessible antennas to use to process a transmission received at the N antennas and sent by a user equipment, and processing the transmission from the user equipment at least by using baseband information from the k antennas. An apparatus includes one or more processors and one or more memories including computer program code. The one or more memories and the computer program code are configured to, with the one or more processors, cause the apparatus to perform at least the following: selecting a subset k of N accessible antennas to use to process a transmission received at the N antennas and sent by a user equipment; and processing the transmission from the user equipment at least by using baseband information from the k antennas. Additional apparatus, computer programs, and computer program products are disclosed.




aperture

Method for making an elastomeric apertured web

A method for making an elastomeric apertured web comprises providing a precursor web comprising a laminate which is subjected to incremental stretching to form an elastomeric precursor web. A forming apparatus is provided comprising a first member and a second member, wherein the first member comprises a mating member, and the second member comprises teeth which are joined to the second member. The elastomeric precursor web is moved through the forming apparatus, wherein apertures are formed in the elastomeric precursor web material as the teeth on the second member penetrate the mating member forming an elastomeric apertured web. The elastomeric apertured web exhibits a WVTR of at least about 1000 g/m2/day.




aperture

APERTURE CODING FOR A SINGLE APERTURE TRANSMIT RECEIVE SYSTEM

An integrated circuit (IC) of a frequency-modulated continuous wave (FMCW) coded aperture radar (CAR) configured to step through a range of frequencies in each sweep and a method of assembling the FMCW CAR are described. The IC includes an antenna element to transmit and receive at a given time duration, a transmit channel to process a signal for transmission, the transmit channel including a transmit switch to change a state of a transmit phase shifter between two states based on a first code, and a receive channel to process a received signal, the receive channel including a receive switch to change a state of a receive phase shifter between two states based on a second code. The IC also includes a switch controller to control the first code and the second code, wherein the switch controller controls the first code to remain constant within the sweep.




aperture

Target scattering mechanism in polarimetric synthetic aperture radar: interpretation and application / Si-Wei Chen, Xue-Song Wang, Shun-Ping Xiao, Motoyuki Sato

Online Resource




aperture

Monitoring evaporite karst activity and land subsidence in the Holbrook Basin, Arizona using interferometric synthetic aperture radar (InSAR)




aperture

Stomatal density and aperture in four species of pleurothallid orchids (Orchidaceae)