Parameter Estimation and the Use of Catalog Data with TRNSYS

Under the supervision of Professors William Beckman and John Mitchell; 455pp.Due to assumptions, idealizations, and detailed specifications often required by existing TRNSYS components, difficulties are encountered in modeling the performance of cataloged components within TRNSYS transient thermal system simulations. A cataloged component is defined as a component whose performance is described by a manufacturer's catalog data. This performance data may be in either tabular or graphical form. To avoid these difficulties, a method has been developed for modeling cataloged components within TRNSYS. This method defines characteristic performance parameters through the manipulation of the basic equations governing the behavior of the component. These characteristic parameters are often combinations of terms, such as geometric specifications, fin efficiencies, or other quantities that require detailed knowledge of the construction of the component. Such detailed information is generally not found in manufacturers' catalogs. Other terms from the basic equations, such as fluid transport properties, are retained to provide a robust model. This method has been successfully used to predict the performance of sensible heat exchangers, chilled water cooling coils, and direct expansion cooling coils. Originally developed with the Engineering Equation Solver (EES) software package, the parameter estimation routine has been programmed to operate in the TRNSYS environment. Using a TRNSED interface, an Input Data File, a standard TRNSYS Type, and an optimization subroutine from a library of numerical routines, the best-fit values of the characteristic parameters are determined. These values can then be used in a TRNSYS simulation that utilizes that particular cataloged component

LHC interaction region quadrupole cryostat production, alignment, and performance summary

The cryostat of a Large Hadron Collider (LHC) Interaction Region (IR) quadrupole magnet consists of all components of the inner triplet except the magnet assembly itself. It serves to support the magnet accurately and reliably within the vacuum vessel, to provide all required cryogenic piping, and to insulate the cold mass from heat radiated and conducted from the environment. The major components of the cryostat are the vacuum vessel, thermal shield, multi-layer insulation system, cryogenic piping, interconnections, and suspension system. While responsibility for the design and manufacture of the main quadrupole elements is divided between Fermilab and KEK, Fermilab alone is responsible for the design and final assembly of the cryostat for the LHC inner triplets. This paper describes the experience gained during fabrication of the first complete Q2 magnets, the alignment operation and results, and the cryogenic performance of the magnet on the test stand at Fermilab. 4 Refs

Production LHC HTS power lead test results

The Fermilab Magnet test facility has built and operated a test stand to characterize the performance of HTS power leads. We report here the results of production tests of 20 pairs of 7.5 kA HTS power leads manufactured by industry for installation in feed boxes for the LHC Interaction Region quadrupole strings. Included are discussions of the thermal, electrical, and quench characteristics under "standard" and "extreme" operating conditions, and the stability of performance across thermal cycles

Field quality measurements of the LQXB inner triplet quadrupoles for LHC

As a part of the USLHC program, Fermilab is building half of the inner triplet quadrupole magnets for the LHC. Two identical quadrupoles (MQXB) with a dipole corrector between them in a single cryogenic unit (LQXB) comprise the Q2 optical element of the final focus triplets in the interaction regions. The 5.5 m long MQXB have a 70 mm aperture and operate in superfluid helium at 1.9 K with a peak field gradient of 215 T/m. Manufacturing of the 18 magnets is in an advanced stage. A program of magnetic field quality measurements of the magnets is performed at room temperature during magnet fabrication as well as at superfluid helium temperature during the cold qualification of each magnet. Results of the measurements are summarized in this paper. (12 refs)

Test results of LHC interaction regions quadrupoles produced by Fermilab

The US-LHC Accelerator Project is responsible for the production of the Q2 optical elements of the final focus triplets in the LHC interaction regions. As part of this program Fermilab is in the process of manufacturing and testing cryostat assemblies (LQXB) containing two identical quadrupoles (MQXB) with a dipole corrector between them. The 5.5 m long Fermilab designed MQXB have a 70 mm aperture and operate in superfluid helium at 1.9 K with a peak field gradient of 215 T/m. This paper summarizes the test results of several production MQXB quadrupoles with emphasis on quench performance and alignment studies. Quench localization studies using quench antenna signals are also presented

Field measurement of a Fermilab-built full scale prototype quadrupole magnet for the LHC interaction regions

Superconducting low-beta quadrupole magnets for the interaction regions of the Large Hadron Collider have been developed by the US- LHC Accelerator Project. These 70 mm bore 5.5 m long quadrupoles are intended to operate in superfluid helium at 1.9 K with a nominal field gradient of 215 T/m. Following a series of 2 m long models, a full scale cryostated cold mass has been fabricated and cold tested at Fermilab. Magnetic field measurements of the prototype, including determination of the field axis using a single stretched wire, have been performed. These measurements and comparisons with results from the model magnets as well as field quality and alignment requirements are reported in this paper. (8 refs)

Quenching behaviour of quadrupole model magnets for the LHC inner triplets at Fermilab

The US-LHC Accelerator Project is responsible for the design and production of inner triplet high gradient quadrupoles for installation in the LHC Interaction Region. The quadrupoles are required to deliver a nominal field gradient of 215 T/m in a 70 mm bore, and operate in superfluid helium. As part of the magnet development program, a series of 2 m model magnets have been built and tested at Fermilab, with each magnet being tested over several thermal cycles. This paper summarizes the quench performance and analysis of the model magnets tested, including quench training, and the ramp rate and temperature of the magnet quench current. (7 refs)