Using the results found previously [5] for the cooling rates of the emittances, due to collisions between the electrons and the ions, a result is found for the friction force acting on the ions. It is shown that the friction force found here when used to track the ion bunch will give the same emittance cooling rates as those found using the intrabeam scattering theory for electron cooling [5].F...

High-energy electron cooling, presently considered as an essential tool for several applications in high-energy and nuclear physics, requires an accurate description of the friction force which ions experience by passing through an electron beam. Present low-energy electron coolers can be used for a detailed study of the friction force. In addition, parameters of a low-energy cooler can be chos...

Wearless dry friction of an elastic block of weight N , driven by an external force F over a rigid substrate, is investigated. The slider and substrate surfaces are both microscopically rough, interacting via a repulsive potential that depends on the local overlap. The model reproduces Amontons’s laws which state that the kinetic friction force is proportional to the normal loading force N and ...

This article describes the design of a new test rig for measuring the friction force in pneumatic components and seals. The test rig was designed in order to measure both the overall friction force in a pneumatic cylinder or a valve as a whole, and the single contribution to friction force caused by the sliding seals. To this end, special fixtures and devices were designed and manufactured in o...

PACS. 82.20K-Potential energy surfaces for chemical reactions. PACS. 71.45N-Calculations of total electronic binding energy. PACS. 68.65-Layer structures, intercalation compolU1ds and superlattices: growth, structure and non-electronic properties. PACS. 61.16D-Electron microscopy determinations (inc. scanning tunnelling microscopy methods). Abstract.-We investigate the microscopic mechanism of ...

Needle insertion can be performed with the aid of an ultrasound (US) image. Detecting the position of a needle in a US image requires considerable technical expertise. To detect whether the needle has reached the target, the physician usually relies on physically sensing the amount of force being fed back from the tip of the needle to their fingertip. The goal of our research was to develop a f...

A variable temperature, ultrahigh vacuum atomic force microscope AFM was used to characterize interfacial friction for a single-asperity diamond contact on a diamondlike carbon DLC substrate over a nominal substrate temperature range of 90 to 275 K. Calibrated friction force measurements were obtained by analyzing lateral force hysteresis loops as a function of normal force. For sufficiently la...

Everyone learns the basics of friction in high-school physics classes: the friction force experienced by a sliding object is proportional to the normal force that an object exerts on a surface. Remarkably, this extremely simple and empirical relation, known as Amontons’ Law, is still often used in creating the most technologically sophisticated machines and devices, even though friction is know...

A model reference adaptive controller (MRAC) for compensating friction and payload uncertainties in a servopneumatic actuation system is presented in this paper. A friction model combining viscous and Coulomb friction is formulated within the framework of an adaptive controller. Due to the asymmetric nature of Coulomb friction in pneumatic piston actuators, a bi-directional Coulomb friction mod...