Crystal collimation experiment on 70-GeV proton accelerator

The first proof-of-principle experiment on "crystal collimation" was performed with 70-GeV protons on IHEP accelerator. A bent crystal installed in the ring as a primary element upstream of a collimator has reduced the radiation levels downstream in the accelerator by a factor of two. The measurements agree with Monte Carlo predictions

Proton Extraction from IHEP Accelerator Using Bent Crystals

IHEP Protvino has pioneered the wide practical use of bent crystals as optical elements in high-energy beams for beam extraction and deflection on permanent basis since 1989. In the course of IHEP experiments, crystal channeling has been developed into efficient instrument for particle steering at accelerators, working in predictable, reliable manner with beams of very high intensity over years. Crystal systems extract 70 GeV protons from IHEP main ring with efficiency of 85% at intensity of 1.E12, basing on multi-pass mechanism of channeling proposed theoretically and realised experimentally at IHEP. Today, six locations on the IHEP 70-GeV main ring of the accelerator facility are equipped by crystal extraction systems, serving mostly for routine applications rather than for research and allowing a simultaneous run of several particle physics experiments, thus significantly enriching the IHEP physics program. The long successful history of large-scale crystal exploitation at IHEP should help to incorporate channeling crystals into accelerator systems worldwide in order to create unique systems for beam delivery. We report recent results from the research and exploitation of crystal extraction systems at IHEP.Comment: Invited talk at the International workshop "Relativistic Channeling and Related Coherent Phenomena", Frascati (Rome) 23-26 March 200

High-efficiency beam extraction and collimation using channeling in very short bent crystals

silicon crystal was used to channel and extract 70 GeV protons from the U-70 accelerator with an efficiency of 85.3±2.8%, as measured for a beam of ∼1012 protons directed towards crystals of ∼2 mm length in spills of ∼2 s duration. The experimental data follow very well the prediction of Monte Carlo simulations. This demonstration is important in devising a more efficient use of the U-70 accelerator in Protvino and provides crucial support for implementing crystal-assisted slow extraction and collimation in other machines, such as the Tevatron, RHIC, the AGS, the SNS, COSY, and the LHC

Advances in the investigation of the extraction of a proton beam from the U-70 accelerator with the aid of bent single crystals

The efficiency of the extraction of a beam from an accelerator is radically improved owing to the application of short crystals of length up to 1.8 mm bent through a small angle of about 1 mrad. This success is due to an increase in the multiplicity of particle transmission through the crystal used. A record efficiency of the extraction of 70-GeV protons in excess of 80% is achieved experimentally, this result being in agreement with theoretical predictions. It is shown that the crystal can efficiently operate at the injection energy of 1.3 GeV