IMMW15

Session Abstracts

Tuesday, August 21 -- Friday, August 24

Tuesday, 8/21, 9:00 AM

FNAL Overview

Phil Schlabach, Fermilab

Future activities on magnets and measurements at CERN

Louis Walckiers, CERN

Tuesday, 8/21, 9:50 AM

Overview of magnetic measurements at CERN

Marco Buzio, CERN

This talk reviews briefly the overall status of measurement facilities
for accelerator magnets at CERN. A summary of the main test results and
technical advances intervened since last IMMW is given. The current
capabilities of the laboratory for both superconducting and resistive
magnets are listed, and the potential for collaborations with
institutions and industries is highlighted.

Tuesday, 8/21, 10:35 AM

BNL Overview

Animesh Jain, BNL

SLAC Overview

Zachary Wolf, Stanford Linear Accelerator Center

Tuesday, 8/21, 11:00 AM

Hall probe polarity checker

Dana Walbridge, Fermi National Accelerator Laboratory

Tuesday, 8/21, 11:25 AM

Applications of Hall probes calibrated in 3 dimensions

Felix Bergsma , CERN

Description of a rotary calibration device using 3 pick up coils and an
NMR to determine the magnetic field very precisely. Versions exist for
dipoles and solenoids. The measured Hall-voltage as function of theta
and phi is decomposed into spherical harmonics. The 3D B-sensors are
used in ATLAS toroids (1800), ATLAS solenoid mapper, CMS (80), CMS
solenoid mapper (4.5 Tesla), LHCb, ALICE. The precision and long time
behaviour is discussed. Future plans: miniaturization, high fields,
better read-out.

Tuesday, 8/21, 1:30 PM

Hall Probe Measurements of Supernanogan

Evans Douglas, TRIUMF

Supernanogan is a multicharge ion source magnet made of permanent magnet
material. Multi B components exist in the structure requiring precise
magnet measurements in all directions. Measurement techniques and
analysis will be presented.

Tuesday, 8/21, 1:55 PM

Hall Probe Studies in High Field Dipoles and Solenoids

Michael Tartaglia, Fermi National Accelerator Laboratory

Tuesday, 8/21, 2:20 PM

Construction and commissioning of a 3-D Hall probe bench for insertion
devices measurements at ALBA Synchrotron Light Source

Jordi Marcos Ruzafa, CELLS

In order to characterize the insertion devices to be installed at new
ALBA synchrotron light source that is being built in Barcelona
(Catalonia, Spain), a new ID laboratory has been set up. One of its
elements is a pre-existing point-to-point Hall probe bench that has been
adapted for narrow gap undulator characterization. The adaptation has
included: the design and fabrication of a new 3-D head to allocate and
ensure the Hall probe stabilization in temperature; the construction of
a zero magnetic field chamber; the development of a new control software
based on TANGO to carry out on-the-fly measurements; the development of
a new 3-D calibration method, and; the development of a method to
guarantee high quality measurements determining the relative positions
of the 3 Hall probes. Hall probe accuracy achieved in the measurement of
magnetic field is ±0.5 G absolute, and the agreement of field integrals
measured with Hall probe with flipping coil results is within ±10 G.cm.
All these improvements and the results obtained will be presented.

Tuesday, 8/21, 2:45 PM

A magnetic measuring bench with pneumatic motors

Felix Bergsma, CERN

Description of the ATLAS solenoid mapper, which was equipped with three
pneumatic vane engines, controlled by piezo-electric valves and a motion
controller. Results and possible improvements are discussed.

Tuesday, 8/21, 3:35 PM

What\'s cooking at Metrolab:

Phillip Keller , Metrolab

Update on the Precision Teslameter PT2026

Prototype of NMR mapping system for small-bore magnets

Ultra-compact Three-axis Hall Magnetometer

Tuesday, 8/21, 3:55 PM

High Sensitivity Hall IC

Brian Richter , GMW

The Sentron CSA-1V high sensitivity Hall effect Integrated Circuit with
a field range to about 7mT (70G), field resolution of about 0.01mT
(0.1G) and frequency response from dc to 100kHz, provides the
possibility of high stability field measurements in the field range
between fluxgates and standard Hall devices. The small size, low power,
and low cost of the CSA-1V IC allows packaging three IC in a small
Module to achieve measurement of the three field components and
calculation of the total field and the field angle. Potential
applications include: - A Field Probe Array of Three Axis Modules to
fast, accurate maps the magnetic field in difficult to access processing
chambers as for plasm etch and deposition. - A Three-Axis Module in a
small Personal device to measure total magnetic field and give an
audible warning above a preset field level such as 0.5mT (5G). -
Three-Axis Modules positioned outside magnets to measure the fringe
field and give an independent measure of magnet status, eg magnet on,
magnet polarity, approximate excitation level. - Three-Axis Modules
positioned near critical electrical equipment such as motors and
transformers to monitor harmonic content as an aid to non-contact
equipment condition monitoring. For applications where a low duty cycle
is adequate, the fast response of the CSA-1V allows for a short sample
period and then a sleep period, for low average power and long-term
battery operation with wireless communication.

Tuesday, 8/21, 4:15 PM

PXI Express for Real-Time Control and High Performance Acquisition

Jonathan Hildyard , National Instruments

Since its release in 1998, the PXI industry standard has quickly gained
adoption in a variety of measurement and automation systems including
Fermilab's semiconductor quench detection and protection system. Two
motivators for adopting the PXI platform are the high-speed PCI data
communication bus and integrated timing and triggering features. Now, as
the commercial PC industry improves bus bandwidth by evolving PCI to PCI
Express, PXI has evolved by integrating PCI Express into the PXI
standard to create PXI Express. This paper gives an overview of the PXI
platform including the data bus and Timing and Triggering features of
PXI and PXI Express.

Tuesday, 8/21, 4:35 PM

Recent Results from an Optical Magnetometer Research Program

Neil Bednar , Tai-Yang Research Corp.

Tai-Yang Research reports on tests performed with an optical
magnetometer as part of a DoE SBIR project. Optical measurement of B\*dl
was obtained for various magnets, including solenoids, dipoles, and
quadrupoles. Measurements were also made on magnetic fields generated by
large, single conductors carrying currents up to 18kA as an alternative
method current monitoring. Research was conducted at FNAL, LBL, and the
NHMFL.

Wednesday, 8/22, 9:00 AM

Undulator Measurements For The LCLS

Zachary Wolf , Stanford Linear Accelerator Center

The LCLS project at SLAC requires 40 undulators: 33 in the beam line, 6
spares, and one reference undulator. A new facility was constructed at
SLAC for tuning and fiducializing the undulators. The throughput of the
facility must be approximately one undulator per week. The undulator
tuning has been partially automated. Fiducialization techniques have
been devised. The new facility, the tuning techniques, and the
fiducialization techniques will be presented.

Wednesday, 8/22, 9:25 AM

Magnetic Measurements of the new APPLE-II type EPU for the ALS MERLIN
Beamline

Arnaud Madur , Lawrence Berkeley National Laboratory

A new Apple-II type Elliptically Polarizing Undulator has been
fabricated for installation in the Advanced Light Source for the MERLIN
Beamline. The new insertion device has a 90 mm period. The magnetic
structure is quasi periodic to reduce or shift the intensity of the
third and fifth radiation harmonics away from multiples integer of the
fundamental \[1\], \[2\]. This presentation will show the results of
magnetic measurements and will compare measurements with the predicted
magnetic characteristics.\
\
\[1\] S. Hashimoto, S. Sasaki, Nuclear Instruments and Methods A, Vol.
361, p. 611, 1995.\
\[2\] Development of quasiperiodic undulator at ESRF, J. Chavanne, P.
Elleaume, P. Van Vaerenbergh ESRF, B. P., PAC proceedings, 1998.\
\[3\] Studies of the Nonlinear Dynamics Effects of APPLE-II Type EPUs at
the ALS, EPAC proceedings, 2006.

Wednesday, 8/22, 9:50 AM

Magnetic Calibration System for Rotating-Coil-Based Measurement
Instrumentation

Olaf Dunkel , CERN

A huge number of magnetic measurements on different types of CERN\'s
superconducting magnets for the LHC required the development of a
calibration system for rotating-coil-based measurement instruments. The
presentation describes the system and it\'s components, shows
calibration and measurement results, cross checks, improvments and
planned developments.

Wednesday, 8/23, 10:35 AM

LCLS small aperture quadrupole test

Isaac Vasserman , Argonne National Laboratory

Magnetic measurement technique used for APS storage ring quadrupoles can
not be applied for such small aperture. So the technique usually applied
for insertion devices was used instead. Results of Hall probe and long
coil measurements are described.

Wednesday, 8/22, 11:00 AM

FAME (Fast Magnetic Measurement with rotating coils)

Juan Garcia Perez, CERN

A project to improve by more than two orders of magnitude the time
response of the magnetic measurements with rotating coils is going on at
CERN in the context of the LHC project. Mechanics of long shafts has
been modified to rotate as fast as 8 Hz. A new rotation unit has been
designed. Three groups of 4 segments of 1.3 m will be connected in
series to cover the 15 m long dipoles. Tests of the systems have been
done at special test bench with dipoles and quadrupoles and at LHC
dipoles. We found encouraging results up to 8 Hz. New data acquisition
system will be associated to it based on PCI-PXI environment and a new
Fast Digital Integrator. Status of the project and first results will be
presented.

Wednesday, 8/22, 11:25 AM

Rotating Circuit Board Probes for Magnetic Measurements

Joseph DiMarco , Fermi National Accelerator Laboratory

The design, construction, and analysis of magnetic measurements probes
made from commercial circuit boards are presented. These prove to have
comparable sensitivity to standard rotating coil designs, bucking ratios
in the thousands, and are robust and generally inexpensive.

Wednesday, 8/22, 1:30 PM

Field reconstruction in elliptic apertures for rotating coil probes

Pierre Schnizer , Gesellschaft fur Schwerionenforschung

Elliptical beam apertures are commonly found in accelerator magnets.
Rotating coils are often applied to such measurements if the whole
region of interest should be covered. We consistently describe the field
in the aperture using elliptic multipoles and further transformations
between cylindrical ones at different positons. Based on that we show
how measurement ats different positions allow to reconstruct the field
within the ellipse.

Thursday, 8/23, 9:00 AM

CERN FDI (Fast Digital Integrator)

Juan Garcia Perez , CERN

At CERN a new Fast Digital Integrator (FDI) has been designed to satisfy
new more demanding requirements of dynamic accuracy and trigger
frequency in magnetic measurements based on rotating coils. It will be
based on PCI-PXI acquisition environment. It consists on a single board
with a daughter encoder board. A bandwidth up to 50-100 kHz and dynamic
accuracy of 10 ppm are targeted. A Programmable Gain Amplifier (PGA) and
an Analogic-Digital Converter (ADC) are the core of this machine with
automatic correction in real time of the offset and gain. It also
includes a DSP as main board processor that handles the measurement
algorithm for the on-line integration. The presentation will shown the
description of the integrator characteristics and the results obtained
on the last prototype.

Thursday, 8/23, 9:25 AM

Field Quality Measurements at High Ramp Rates

Animesh Jain , Brookhaven National Laboratory

BNL has built a prototype superconducting dipole for the Facility for
Antiproton and Ion Research (FAIR) at GSI that can be ramped at a high
rate (1-4 T/s). To characterize the field quality at such high ramp
rates, a measurement system consisting of 16 printed circuit windings
was developed. In this system, the signals induced in all the windings
as the magnet is ramped are analyzed to obtain the field harmonics.
Initial measurements \[1\] with this system suffered from somewhat poor
resolution of the ADCs used for data acquisition. Also, only a few low
order harmonics could be obtained with the 16 signals. These drawbacks
have been addressed by replacing the ADCs with HP3458A voltmeters and by
combining data taken with two different orientations of the probe. This
has allowed us to measure very precisely (\~10 ppm of the dipole field)
all the harmonics up to the 26-pole at ramp rates up to 4.3 T/s.

Thursday, 8/23, 9:50 AM

A SLOWLY ROTATING COIL SYSTEM FOR AC FIELD MEASUREMENTS OF FERMILAB
BOOSTER CORRECTORS

Gueorgui Velev , Fermi National Accelerator Laboratory

A method for measurement of rapidly changing magnetic fields has been
developed and applied to the testing of new room temperature corrector
packages designed for the Fermilab Booster Synchrotron. The method is
based on fast digitization of a slowly rotating tangential coil probe,
with analysis combining the measured coil voltages across a set of
successive magnet current cycles. This paper presents results on the
field quality measured for the normal and skew dipole, quadrupole, and
sextupole elements in several of these corrector packages

Thursday, 8/23,10:35 AM

Development of a Mole for Measuring Pulsed Superconducting Magnets

Pierre Schnizer , Gesellschaft fur Schwerionenforschung

For FAIR 6 different synchrotron- and storage rings are to be built; two
synchotron rings with superconducting magnets operate in pulsed
operation and the collector ring operate in DC mode. The magnets of
these machines need to be measured with an accuracy of 600 ppm for the
main field and 100 ppm for the field homogeneity. We present a mole
capable of measuring these magnets based on the rotating coil probe for
the DC measurement and on the step coil for the AC measurement. The
design decisions are illustrated next to the selected devices. Finally
an estimate of the measurement precision is given based on measurements
and calculations.

Thursday, 8/23, 11:00 AM

Fixed Coil Array Measurements of Fast-Ramping Booster Corrector Magnets

Joseph DiMarco , Fermi National Accelerator Laboratory

A system employing an array of inductive pick-up coils around the
perimeter of a cylinder has been developed for measurements of the
rapidly changing field in the new corrector magnets for the Fermilab
Booster. The coils are fabricated on printed circuit boards and feature
windings which buck dipole, quadrupole, and sextupole fields, allowing
sensitive measurements of both strength and higher-order harmonics. The
array of coils is simultaneously sampled at data rates of up to 100kHz
with 10kHz bandwidth using 24-bit ADC.s. A detailed overview of the
system is presented, along with a characterization of results and system
performance.

Thursday, 8/21, 11:25 AM

Decay and Snapback Measurements for Tevatron

Gueorgui Velev , Fermi National Accelerator Laboratory

A systematic study of the persistent current decay and snapback effect
in the fields of Tevatron accelerator dipoles was performed at the
Fermilab Magnet Test Facility. The decay and snapback were measured
under a range of conditions including variations of the current ramp
parameters and magnet operational history. The study has mostly focused
on the dynamic behavior of the normal sextupole component. In addition,
we will presents the persistent current effects observed in the other
allowed field harmonics.

Thursday, 8/23, 1:30 PM

Dynamic effects in CNAO magnets

Regis Chritin , CERN

For the CNAO medical accelerator, the dynamic behaviour is critical due
to the limited time of treatment for the patients. The ramp up and ramp
down of the field has been studied for the synchrotron dipoles as well
as the transfer line dipoles and quadrupoles. Eddy current effects in
the magnets and in material samples are discussed.

Thursday, 8/23, 1:55 PM

Ramp rate effect on the field quality of the LHC superconducting magnets

Guy Deferne , CERN

Induced coupling currents circulating among the strands of the
superconducting cables as well as among the filaments of the strands
will affect the magnetic field of the main LHC magnets during the
acceleration ramp from injection current (I=760 A) up to nominal current
(I=11850 A). This contribution, proportional to the ramp-rate, will
generate a field perturbation that has been measured during the series
tests of the LHC superconducting dipoles and quadrupoles. We present
here a description of the measurement techniques focusing on the
experimental set-up used to measure the ramp rate effect of the main
component of the field (Field Advance). We report also the results
obtained on a sample of LHC dipoles and quadrupoles. A small Field
Advance contribution of about 1-2 units and a negligible ramp rate
effect on multipoles were measured at injection current and for a
nominal ramp rate of 10 A/s in both types of magnets. These results are
consistent with inter-strand resistance values Rc in excess of 50 ;
estimated from AC loss measurements.

Thursday, 8/23, 2:20 PM

Determination of Magnetic Axis in a Sextupole magnet using Vibrating
Wire Technique

Alexander Temnykh , Cornell University

Future light sources, such as the upcoming NSLS-II at BNL, will require
precise alignment of a string of quadrupole and sextupole magnets on a
\~6 m long girder within a tight tolerance of +/-10-20 microns. The
vibrating wire technique has already been demonstrated to be capable of
such precision for quadrupole magnets. Motivated by the requirement of
precise sextupole magnet alignment, we have applied the vibrating wire
technique to find the magnetic axis of a 24 cm long sextupole with an
integrated strength of 10.9 T/m. The experimental set up will be
described, and the results will be presented, along with a discussion of
the possible sources of errors.

Thursday, 8/23, 2:45 PM

Measurement of Wire Sag in a Vibrating Wire Setup

Animesh Jain , Brookhaven National Laboratory

The vibrating wire technique is a powerful method to precisely determine
the magnetic axis of quadrupoles and other higher order multipoles, and
is being considered for the alignment of magnets on a girder for the
NSLS-II project at BNL. The goal is to align several magnets mounted on
\~6 m long girder within a tolerance of +/-10-20 microns. For a wire
stretched over such a long distance, the sag of the wire can be as much
as 500-600 microns. It is, therefore, necessary to estimate the sag very
precisely in order to meet the desired tolerance. We have checked the
validity of estimating the sag from the fundamental resonance frequency
by directly measuring the changes in the wire vertical position as a
function of applied tension. A simple LED/photodetector combination,
commonly used for detecting wire motion in vibrating wire studies, was
used to measure the wire position accurately. Results of these
measurements will be presented.

Solenoid Axis Measuement with the Single Stretched Wire System

Joseph DiMarco , Fermi National Accelerator Laboratory

An attempt was made to measure the axis of the HINS solenoid with the
SSW system. A very brief presentation of first results.

Thursday, 8/23, 4:00 PM

Biomagnetism:

Measuring and Imaging the Natural and Disease Fields from the Human Body

(Invited colloquium presentation)

Edward Flynn , Senior Scientific, LLC

Biomagnetism involves the measurement of the magnetic fields emanating
from biological tissue with the emphasis being on human beings. The
fields are small, ranging from femto- to pico-Tesla and are measured
with sensitive instruments; typically SQUIDs with sensitivities of
several fT. An example of natural field measurements is
magnetoencephalography where large SQUID arrays are being used to image
magnetic sources in normal and abnormal human brain behavior arising
from neuronal currents. A new area of biomagnetism involves the use of
targeted magnetic nanoparticles in the early detection of disease. These
superparamagnetic particles offer unique characteristics for localizing
disease sites ranging from various types of cancer to neurological
diseases. By using small pulsed magnetic polarizing fields, SQUID
sensors detect small numbers of cells in the body targeted by
antibody-labeled nanoparticles through their decaying remanence fields.
Localization of these biomagnetic sources in the body involves
theoretical modeling of the inverse electromagnetic problem.

Friday, 8/24, 9:00 AM

Architecture and Features of an Extensible Measurement System Framework

Jerzy Nogiec , Fermi National Accelerator Laboratory

The architecture of the Extensible Measurement System (EMS) will be
discussed. EMS is a universal Java-based framework for building data
analysis and measurement systems. It was designed with a goal to replace
a multitude of different systems with a single expandable system,
capable of accommodating various test and analysis scenarios and varying
algorithms. The EMS framework is based on component technology,
graphical assembly of programs, introspection and flexibility to
accommodate various data processing and data acquisition
(hardware-oriented) components.

Friday, 8/24, 9:25 AM

Development of a Software Framework for Magnetic Measurements at CERN

Marco Buzio , CERN

Summary Sessions: