Influence of Proton Irradiation on Angular Dependence of Second Generation (2G)HTS Page: 3 of 5
This article is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided to UNT Digital Library by the UNT Libraries Government Documents Department.
Extracted Text
The following text was automatically extracted from the image on this page using optical character recognition software:
BNL-95242-2011-CP
Submitted at the Particle Accelerator Conference (PACl1), New York City, NY - March 28-April 1, 2011
INFLUENCE OF PROTON IRRADIATION ON ANGULAR DEPENDENCE
OF SECOND GENERATION (2G) HTS*
Y. Shiroyanagi, G. Greene, R. Gupta, W. Sampson, BNL, Upton, NY 11973, U.S.AAbstract
In the Facility for Rare Isotope Beams (FRIB) the
quadrupoles in the fragment separator are exposed to very
high radiation and heat loads. High Temperature
Superconductors (HTS) are a good candidate for these
magnets because they can be used at -30-50 K and
tolerate higher heat generation than Nb-Ti magnets.
Radiation damage studies of HTS wires are crucial to
ensure that they will survive in a high radiation
environment. HTS wires from two vendors were studied.
Samples of 2G HTS wires from SuperPower and
American Superconductor (ASC) were irradiated with a
42 pA, 142 MeV proton beam from the Brookhaven
Linac Isotope Producer (BLIP). The angular dependence
of the critical current was measured in magnetic fields at
77K.
BACKGROUND
This paper describes a radiation damage study of the
superconductor that will be exposed to a high level of
radiation in the magnets for the Facility for Rare Isotope
Beams (FRIB) [1]. A 400 kW beam will hit the
production target to produce a copious amount of various
rare isotopes, one of which is selected in the fragment
separator. Quadrupoles in the fragment separator are
exposed to an unprecedented level of radiation (-20
MGy/year) and heat loads (-10 kW/m or 15 kW in the
first quadrupole itself). High Temperature
Superconductors are a good candidate for FRIB because
they can be used at -30-50 K and tolerate higher heat
generation than Ni-Ti magnets [2-4]. It also has to tolerate
field of 2 - 3T. In order to assure that the HTS will
survive FRIB environment, radiation damage studies are
crucial.
The magnet is being built using conductor from two
vendors to demonstrate the feasibility of HTS in FRIB
magnets [5]. The vendors are SuperPower and American
Superconductor. Several samples of YBCO from
SuperPower and American Superconductor (ASC) were
irradiated with a 42 pA, 142 MeV proton beam from the
Brookhaven Linac Isotope Producer (BLIP). 7cm long
4mm wide samples were mounted on five aluminium
frames and inserted into the water-filled target tank of
BLIP. Five different levels of fluence were achieved by
progressively removing the aluminium frames after
specific times to give 2.5, 25, 50, 75 and 100 p A-hr
*Work supported by the U.S. Department of Energy under Contract
No. DE-AC02-98CH10886 and under Cooperative Agreement DE-
SC0000661 from DOE-SC that provides financial assistance to MSU
to design and establish FRIB.
#yshiroyanagi@bnl.gov(1016, 1017, 2 x 1017, 3 x 1017 and 4 x 1017 protons/cm2,
respectively). 1017 protons/cm2 (25 pA-hrs integrated
dose) is equivalent to over 10 years of FRIB operation
[6]. In a previous study, critical currents of irradiated
4mm wide YBCO conductors at self-field were measured
as shown in Figure 1 [1]. The critical current before
irradiation was -100A. Ic decreases monotonically as
dose level increases. Self-field measurements of YBCO
from both vendors did not show much difference in
critical current Ic.1.1 -
1.0 <
0.9 -
.2 0.8
O. 0.7 -
0.6-
i 0.5 -
m 0.4 -
S0.3 -0
0.2
- 0.1 -
0.00 25 50 75
Radiation Dose (pA.Hours)100
Figure 1 Normalized critical current versus radiation for
self-field.
The purpose of this study is to determine the radiation
damage as a function of field angle and field strength.EXPERIMENT
Figure 2: Top view of the magnet and sample holder.
Field angle zero is defined as perpendicular to the tape
surface.
The samples were stored over a year after the
irradiation to reduce radioactivity. Ex-situ measurements
were conducted in an open cryostat with a resistive+ SuperPower Sample#1
-"-er owe Sam"pe#2
o ASC Sample#1
_ ASCSample#2 a
- ASO Averaae
100 pA.hr dose is - 3.4 X 1017 proton s/cm2
Upcoming Pages
Here’s what’s next.
Search Inside
This article can be searched. Note: Results may vary based on the legibility of text within the document.
Tools / Downloads
Get a copy of this page or view the extracted text.
Citing and Sharing
Basic information for referencing this web page. We also provide extended guidance on usage rights, references, copying or embedding.
Reference the current page of this Article.
Shiroyanagi, Y.; Greene, G.; Gupta, R. & Sampson, W. Influence of Proton Irradiation on Angular Dependence of Second Generation (2G)HTS, article, May 1, 2011; United States. (https://digital.library.unt.edu/ark:/67531/metadc832691/m1/3/: accessed April 23, 2024), University of North Texas Libraries, UNT Digital Library, https://digital.library.unt.edu; crediting UNT Libraries Government Documents Department.