19561136
Innovation in Scholarly Communication: Vision and Projects from High-Energy Physics
Having always been at the forefront of information management and open access, High-Energy Physics (HEP) proves to be an ideal test-bed for innovations in scholarly communication including new information and communication technologies. Three selected topics of scholarly communication in High-Energy Physics are presented here: a new open access business model, SCOAP3, a world-wide sponsoring consortium for peer-reviewed HEP literature; the design, development and deployment of an e-infrastructure for information management; and the emerging debate on long-term preservation, re-use and (open) access to HEP data.
139392511
Results from DESY-Heidelberg NaI lead glass detector
123302351
Results from the JADE Collaboration
Results from the JADE experiment at PETRA in the energy range between 27.7 and 35.8 GeV are reported. QED is tested using the reactions e+e− ⇒ e+e−, μ+μ−, γγ and lower limits on hypothetical cut‐off parameters of up to 100 GeV are obtained. Predictions of the standard electro‐weak theory are compared with the data and limits are derived on the values of the vector and axial vector coupling constants. Extended gauge models containing more than one neutral weak boson are also tested and lower limits are placed on the masses of such bosons.For the reaction e+e− ⇒ hadrons topological distributions of the hadrons are studied. At s√ of about 30 GeV it is shown in a model independent way that the observed planar events actually possess three‐jet structure strongly suggesting gluon bremsstrahlung as the origin of these events. By comparison of the data with the qqg — model we obtain a value for the strong coupling constant of αs (q2) = 0.17 ± 0.02 ± 0.05.At the highest energy of about 35 GeV a search for new flav...
196147152
Experience With the Jade Jet - Chamber at {PETRA} and Pattern Recognition Programs for the Jade Jet - Chamber
118687763
The Future of the CERN Accelerator Complex
This chapter looks back at some of the most memorable achievements in high-energy physics during the 50 years spanning CERN's PS and LHC.
120548581
The OPAL jet chamber
Abstract The characteristic features of the OPAL jet chamber are described, such as the mechanical and electrical structure, the readout electronics, the gas system, and the laser setup for calibration. Results on spatial resolution and on particle identification power, obtained with a full scale prototype chamber, are presented which show that in the final chamber the anticipated performance can be reached.
55001750
Design and construction of a high-duty factor photocathode electron gun
Under a joint collaboration between Grumman and BNL, a high-duty factor (>1%) photocathode electron gun is being constructed for use at the ATF facility at BNL. This gun was designed as the electron source for the proposed UV FEL Users' Facility at BNL. The thermally induced stresses exceed the yield strength of OFHC copper. For this reason, the gun is fabricated from GlidCop, an aluminum oxide dispersion strengthened copper alloy.<<ETX>>
120207704
Design of a high-brightness, high-duty factor photocathode electron gun
Abstract The proposed UV-FEL user's facility at Brookhaven National Laboratory will require a phatocathode gun capable of producing short ( ps ) bunches of electrons at high repetition rates (5 kHz), low energy spread ( ), a peak current of 300 A (after compression) and a total bunch charge of up to 2 nC. At the highest charge, the normalized transverse emittance should be less than 7π mm mrad. We are presently designing a gun that is expected to exceed these requirements. This gun will consist of 3 1 2 cells, constructed of GlidCop-15, an aluminum oxide dispersion strengthened copper alloy. The gun will be capable of operating at duty factors in excess of 1%. Extensive beam dynamics studies of the gun were used to determine the effect of varying the length of the first cell, shaping the apertures between cells, and increasing the number of cells. In addition, a detailed thermal and mechanical study of the gun was performed to ensure that the thermal stresses were well within the allowable limits and that copper erosion of the water channels would not occur.
118814364
An electrostatic sweep plate device for emittance measurement of ion beams to 2 MeV
Electrostatic sweep plate devices have been used previously for the measurement of ion beam emittance. These devices may be routinely designed with an ultimate angle resolution of /spl plusmn/0.25 mrad or less. We have used a similar device for measuring the emittance of H/sup -/ and H/sup +/ beams exiting an RFQ at 1 MeV. This scanner will be used to characterize the beam exiting a low-power DTL at energies up to 2 MeV. The physics design changes consist primarily of increasing the length of the deflection plates and decreasing their separation to obtain high electric field at low deflection plate voltage. The front face of the scanner was made thicker and designed for water cooling to withstand the beam power at up to 2 MeV. The design of the scanner is discussed. This includes the device angular resolution and maximum acceptable angle. The thermal analysis that led to the design of the water-cooled front face is shown. Data showing the performance of the device and resulting emittance measurements at 1 MeV are presented.<<ETX>>