55276670
Warm Magnetic Field Measurements of LARP HQ Magnet
The US-LHC Accelerator Research Program is developing and testing a high-gradient quadrupole (HQ) magnet, aiming at demonstrating the feasibility of Nb{sub 3}Sn technologies for the LHC luminosity upgrade. The 1 m long HQ magnet has a 120 mm bore with a conductor-limited gradient of 219 T/m at 1.9 K and a peak field of 15 T. HQ includes accelerator features such as alignment and field quality. Here we present the magnetic measurement results obtained at LBNL with a constant current of 30 A. A 100 mm long circuit-board rotating coil developed by FNAL was used and the induced voltage and flux increment were acquired. The measured b{sub 6} ranges from 0.3 to 0.5 units in the magnet straight section at a reference radius of 21.55 mm. The data reduced from the numerical integration of the raw voltage agree with those from the fast digital integrators.
44683959
Quench Performance of HQ01, a 120 mm Bore LARP Quadrupole for the LHC Upgrade
We report quench test results for the 1-meter long, 120 mm aperture Nb3Sn quadrupole magnet, HQ01, designed, fabricated and tested for the LHC Accelerator Research Program (LARP). The magnet has a design gradient of 219 T/m at 1.9 K and peak field of ~15 T. Earlier tests (HQ01a, b) showed peak gradients of 152 T/m at 4.4 K but also revealed electrical insulation weaknesses that ultimately led to coil damage. Structural and electrical improvements incorporated into HQ01c magnet have assured and tracked the electrical integrity of the coils. The most recent HQ01d and HQ01e tests demonstrated gradients of 170 T/m at 4.4 K (86% of short sample critical current) with moderate training. By analyzing magnet voltage test data, quench propagation velocities and quench locations were determined. Most of the quenches tended to cluster around the pole region of the coils. Eight PC-board quench antennas were installed to better identify quench locations. We monitored longitudinal propagation of pole-turn quenches and correlated inductive responses of the quench antennas with magnet voltages. On down-ramps, the HQ magnet exhibited no quenches at rates up 150 A/s; the experimental ramp-rate dependence was analyzed using a simple `loss model'.
118342681
A Scenario for Strong Gravity in Particle Physics: An Alternative mechanism for black holes to appear at accelerator experiments
A different reason for the apparent weakness of the gravitational interaction is advanced, and its consequences for Hawking evaporation of a Schwarzschild black hole are investigated. Proceeding from some fundamental thermodynamic observations, a simple analytical formulation predicts that evaporating black holes will undergo a type of phase transition resulting in variously long-lived quantized objects of reasonable sizes, with normal thermodynamic properties and inherent duality characteristics. Speculations on the implications for particle physics are explored, and predictions for possible experimental confirmation of the scenario at LHC are made.
119000586
Quantization of Black Holes in the Shielded Strong Gravity Scenario (I. Neutral Scalar States)
A previously used quantization mechanism is applied to the continuous states of the shielded strong gravity scenario (hep-th/0602183), yielding two types of spectra for uncharged black hole scalars. Each yields the general morphology for states expected in this scenario at LHC and at arbitrarily higher energies, once the parameters are determined by the two lowest-lying scalar states. A particularized example for the preferred type of quantization is numerically evaluated.