An update!
So, many of you probably wonder what I've been doing down in TN for the whole semester. I just had to write an abstract (it may not be quite in it's final form, but it's close) describing just that, so I thought I'd post it and get you up to date. Last names have been dropped to protect probably nobody. But I did it anyway.
The Chicane Node in the ORBIT Injection Upgrade
Daniel -
Albion College, Albion MI
Science Undergraduate Laboratory Internships/Oak Ridge Science Semester
Sarah -, Mentor
Accelerator Systems Division
Oak Ridge National Laboratory
ABSTRACT
The accumulator ring in the Spallation Neutron Source (SNS) will accumulate up to 10^14 protons at a time from a 1 GeV linear accelerator to produce neutrons by spallation. In order to satisfy radiation hazard requirements, no more than 0.01% of the beam in the SNS ring may be lost by collisions with the beam pipe. Since most accelerators lose 1-2% of their beam, the SNS must be far more effective in beam loss control than any previous high-intensity accelerator. This requires very precise understanding of the mechanisms which contribute to beam loss. One of the main sources of loss in the accelerator is in the injection area of the ring, where H- particles are converted to protons by passing through a thin foil that strips off the electrons. Some of the H- particles are not fully stripped, and live for a short time as H0 particles in excited quantum states before decaying in the ring magnetic fields. If the magnetic fields are not optimized, particles that decay may be deflected from the paths intended for either H- or protons and become lost in the accelerator. The SNS project will upgrade the beam power in the year 2010, and this will require a redesign of the injection region of the ring. Testing of new design schemes will be done primarily with the Objective Ring Beam Injection and Tracking Code (ORBIT), a modular simulation package designed at SNS specifically for modeling high intensity rings. In this project, the ORBIT code was upgraded to allow precise simulations of the injection region of the ring. This work included installing code that performs detailed tracking of all three relevant states of hydrogen through the dipole magnetic fields in the injection region, and determines on each step which neutral particles decay into protons. The physical configuration of the chicane is customizable, allowing particle positions to be compared to the real location of the beam pipe and losses to be determined. The code is configured to allow parallel runs on multiple machines to accommodate computationally intensive tests. Results from this code were benchmarked with previous studies of excited-state decay done by Danilov and Galambos et al, and showed excellent agreement. Future modifications to the ORBIT injection region code may include a foil heating routine and propagation through higher-order magnetic fields. The updated ORBIT code will provide an important tool for optimizing the new injection region design.
In other news, I'll be in A2 for the long thanksgiving weekend, and then again for many weeks starting Dec 10. If you'll be in the area, I'd love to hang out.
The Chicane Node in the ORBIT Injection Upgrade
Daniel -
Albion College, Albion MI
Science Undergraduate Laboratory Internships/Oak Ridge Science Semester
Sarah -, Mentor
Accelerator Systems Division
Oak Ridge National Laboratory
ABSTRACT
The accumulator ring in the Spallation Neutron Source (SNS) will accumulate up to 10^14 protons at a time from a 1 GeV linear accelerator to produce neutrons by spallation. In order to satisfy radiation hazard requirements, no more than 0.01% of the beam in the SNS ring may be lost by collisions with the beam pipe. Since most accelerators lose 1-2% of their beam, the SNS must be far more effective in beam loss control than any previous high-intensity accelerator. This requires very precise understanding of the mechanisms which contribute to beam loss. One of the main sources of loss in the accelerator is in the injection area of the ring, where H- particles are converted to protons by passing through a thin foil that strips off the electrons. Some of the H- particles are not fully stripped, and live for a short time as H0 particles in excited quantum states before decaying in the ring magnetic fields. If the magnetic fields are not optimized, particles that decay may be deflected from the paths intended for either H- or protons and become lost in the accelerator. The SNS project will upgrade the beam power in the year 2010, and this will require a redesign of the injection region of the ring. Testing of new design schemes will be done primarily with the Objective Ring Beam Injection and Tracking Code (ORBIT), a modular simulation package designed at SNS specifically for modeling high intensity rings. In this project, the ORBIT code was upgraded to allow precise simulations of the injection region of the ring. This work included installing code that performs detailed tracking of all three relevant states of hydrogen through the dipole magnetic fields in the injection region, and determines on each step which neutral particles decay into protons. The physical configuration of the chicane is customizable, allowing particle positions to be compared to the real location of the beam pipe and losses to be determined. The code is configured to allow parallel runs on multiple machines to accommodate computationally intensive tests. Results from this code were benchmarked with previous studies of excited-state decay done by Danilov and Galambos et al, and showed excellent agreement. Future modifications to the ORBIT injection region code may include a foil heating routine and propagation through higher-order magnetic fields. The updated ORBIT code will provide an important tool for optimizing the new injection region design.
In other news, I'll be in A2 for the long thanksgiving weekend, and then again for many weeks starting Dec 10. If you'll be in the area, I'd love to hang out.