Nuclear interactions for 15 GeV/c protons and pions under random and channeling conditions in germanium single crystals

doi:10.1016/0550-3213(78)90496-0

Nuclear Physics B

Volume 144, Issue 1, 6 November 1978, Pages 1-21

https://doi.org/10.1016/0550-3213(78)90496-0 Get rights and content

Abstract

Strong directional effects for nuclear-reaction probabilities have been observed when 15 GeV/c protons and pions are incident on a 4.2 mm Ge single crystal. In the random situation, our measurements are in agreement with Glauber's theory of diffraction scattering and with published particle-production data. When protons are incident in an aligned direction, the nuclear-reaction probabilities fall off very drastically but in a way which is in agreement with standard channeling theory; for aligned negative pions where a simple channeling theory is lacking, there is some experimental indication that nuclear-reaction probabilities are enhanced compared to the corresponding random rates, an indication which is supported by detailed computer-simulation studies.

References (18)

H. Esbensen
Phys. Lett.
(1978)
R.J. Glauber et al.
Nucl. Phys.
(1970)
Review of particle properties
Rev. Mod. Phys.
(April 1976)
A. Breskin et al.
Nucl. Instr.
(1975)
H. Esbensen et al., Phys. Rev. A, in...
H. Esbensen
Aarhus University preprint
(1978)
D.S. Gemmell
Rev. Mod. Phys.
(1974)
R.J. GlauberR.J. GlauberR.J. Glauber
J.V. Allaby
CERN Yellow report 70-12
(1970)

There are more references available in the full text version of this article.

Cited by (7)

Channeling and volume reflection of high-energy charged particles in short bent crystals. Crystal assisted collimation of the accelerator beam halo
2019, Physics Reports
Citation Excerpt :
A few experiments on the study of nuclear interactions of high energy protons and heavy nuclei in the aligned crystals have been performed at the external accelerator beams [64–67]. Nuclear interactions of high-energy protons in germanium crystals aligned by the [110] axis with the beam had been studied in [64,65]. A considerable decrease of the nuclear interaction probability was registered in the aligned crystals.
The experimental studies of high-energy charged particle deflection due to planar and axial channeling as well as volume reflection and multi volume reflections in short bent crystals at the extracted beams of the CERN Super Proton Synchrotron (SPS) are considered. The experiments on the studies of crystal assisted collimation of the CERN SPS beam halo and the first similar experiment with the CERN Large Hadron Collider (LHC) beam of 6500 GeV/c protons are also considered.
High-efficiency deflection of high energy protons due to channeling along the (110) axis of a bent silicon crystal
2016, Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
Citation Excerpt :
As predicted in [22] high deflection efficiency and small beam losses due to inelastic interactions may be achieved using the axial channeling, most strongly along the 〈110〉 axis of a silicon crystal. Despite that fact, experimental measurements on AC are limited to studies of the deflection efficiency of 400 GeV/c protons interacting with a 〈111〉 silicon crystal [10,12,21], and measurement of the inelastic nuclear interaction (INI) frequency under AC was observed only for 15 GeV/c pions interacting with germanium crystals [23,24]. In this paper, we experimentally investigate the deflection efficiency and the inelastic interaction frequency of 400 GeV/c protons interacting with 〈111〉 and 〈110〉 bent silicon crystals under axial channeling at the H8 external line of the SPS at CERN.
A deflection efficiency of about $61 %$ was observed for 400 GeV/c protons due to channeling, most strongly along the 〈110〉 axis of a bent silicon crystal. It is comparable with the deflection efficiency in planar channeling and considerably larger than in the case of the 〈111〉 axis. The measured probability of inelastic nuclear interactions of protons in channeling along the 〈110〉 axis is only about $10 %$ of its amorphous level whereas in channeling along the (110) planes it is about $25 %$ . High efficiency deflection and small beam losses make this axial orientation of a silicon crystal a useful tool for the beam steering of high energy charged particles.
Probability of inelastic nuclear interactions of high-energy protons in a bent crystal
2010, Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms
Probability of inelastic nuclear interactions in a short bent silicon crystal for its orientations optimal for channeling and volume reflection was investigated using 400 GeV/c protons of the CERN SPS. The contribution of nuclear interactions from channeled protons was observed to be about 3–4% of the probability for the amorphous orientation. For the crystal orientation optimal for volume reflection the nuclear interaction probability of protons was a few percents larger than in the amorphous case. It was shown that in the limiting case of a quasi parallel beam realizing for the collider beam halo the inelastic nuclear losses should decrease by more than five times, which is an additional advantage of a crystal as a primary collimator for the LHC collimation system.
Bending of high energy beams using axial and planar channeling
1980, Physics Letters B
Channeling in the GeV-region
1980, Nuclear Instruments and Methods
The experimental results from high energy channeling investigations are summarized. For energy loss the strong influence of a density effect and channeling is shown for positive and negative particles with momenta of 2–15 GeV/c and the results are compared to theoretical calculations. Up to 250 GeV/c channeling has been shown to influence dramatically nuclear reaction yields and scattering phenomena. The decahnneling is also shown and compared to calculations.
Modulation of nuclear interactions using channeling at multi-hundred GeV energies
1980, Nuclear Physics, Section B
Channeling of protons and positive and negative pions has been observed in a single crystal of germanium at beam momenta of 35, 100 and 250 GeV/c. Both energy loss and scattering have been measured. The channeling effects agree with observations at lower energies suitably scaled to these high energies. The suppression of inelastic nuclear interactions has been directly observed by monitoring multiple-track events.

View all citing articles on Scopus

View full text

Nuclear interactions for 15 GeV/c protons and pions under random and channeling conditions in germanium single crystals

Abstract

Phys. Lett.

Nucl. Phys.

Rev. Mod. Phys.

Nucl. Instr.

Aarhus University preprint

Rev. Mod. Phys.

CERN Yellow report 70-12