Permanent magnet quadrupoles (PMQs) are an alternative to common electromagnetic quadrupoles especially for fixed rigidity beam transport scenarios at particle accelerators. Using those magnets for experimental setups can result in certain scenarios, in which a PMQ itself may be exposed to a large amount of primary and secondary particles with a broad energy spectrum, interacting with the magnetic material and affecting its magnetic properties. One specific scenario is proton microscopy, where a proton beam traverses an object and a collimator in which a part of the beam is scattered and deflected into PMQs used as part of a diagnostic system. During the commissioning of the PRIOR (Proton Microscope for Facility for Antiproton and Ion Research) high energy proton microscope facility prototype at Gesellschaft für Schwerionenforschung in 2014, a significant reduction of the image quality was observed which was partially attributed to the demagnetization of the used PMQ lenses and the corresponding decrease of the field quality. In order to study this phenomenon, Monte Carlo simulations were carried out and spare units manufactured from the same magnetic material—single wedges and a fully assembled PMQ module—were deliberately irradiated by a 3.6 GeV intense proton beam. The performed investigations have shown that in proton radiography applications the above described scattering may result in a high irradiation dose in the PMQ magnets. This did not only decrease the overall magnetic strength of the PMQs but also caused a significant degradation of the field quality of an assembled PMQ module by increasing the parasitic multipole field harmonics which effectively makes PMQs impractical for proton radiography applications or similar scenarios.

1.
D.
Varentsov
,
O.
Antonov
,
A.
Bakhmutova
,
C. W.
Barnes
,
A.
Bogdanov
,
C. R.
Danly
,
S.
Efimov
,
M.
Endres
,
A.
Fertman
,
A. A.
Golubev
,
D. H. H.
Hoffmann
,
B.
Ionita
,
A.
Kantsyrev
,
Y. E.
Krasik
,
P. M.
Lang
,
I.
Lomonosov
,
F. G.
Mariam
,
N.
Markov
,
F. E.
Merrill
,
V. B.
Mintsev
,
D.
Nikolaev
,
V.
Panyushkin
,
M.
Rodionova
,
M.
Schanz
,
K.
Schoenberg
,
A.
Semennikov
,
L.
Shestov
,
V. S.
Skachkov
,
V.
Turtikov
,
S.
Udrea
,
O.
Vasylyev
,
K.
Weyrich
,
C.
Wilde
, and
A.
Zubareva
, “
Comissioning of the PRIOR proton microscope
,”
Rev. Sci. Instrum.
87
,
023303-1–023303-
8
(
2016
).
2.
M.
Prall
,
M.
Durante
,
T.
Berger
,
B.
Przybyla
,
C.
Graeff
,
P. M.
Lang
,
C.
LaTessa
,
L.
Shestov
,
P.
Simoniello
,
C.
Danly
,
F.
Mariam
,
F.
Merrill
,
P.
Nedrow
,
C.
Wilde
, and
D.
Varentsov
, “
High-energy proton imaging for biomedical applications
,”
Sci. Rep.
6
,
27651
(
2016
).
3.
N.
King
,
E.
Ables
,
K.
Adams
,
K.
Alrick
,
J.
Amann
,
S.
Balzar
,
P.
Barnes
, Jr.
,
M.
Crow
,
S.
Cushing
,
J.
Eddleman
,
T.
Fife
,
P.
Flores
,
D.
Fujino
,
R.
Gallegos
,
N.
Gray
,
E.
Hartouni
,
G.
Hogan
,
V.
Holmes
,
S.
Jaramillo
,
J.
Knudsson
,
R.
London
,
R.
Lopez
,
T.
McDonald
,
J.
McClelland
,
F.
Merrill
,
K.
Morley
,
C.
Morris
,
F.
Naivar
,
E.
Parker
,
H.
Park
,
P.
Pazuchanics
,
C.
Pillai
,
C.
Riedel
,
J.
Sarracino
,
F.
Shelley
, Jr.
,
H.
Stacy
,
B.
Takala
,
R.
Thompson
,
H.
Tucker
,
G.
Yates
,
H.-J.
Ziock
, and
J.
Zumbro
, “
An 800-MeV proton radiography facility for dynamic experiments
,”
Nucl. Instrum. Methods Phys. Res., Sect. A
424
,
84
91
(
1999
).
4.
C.
Morris
,
N.
King
,
K.
Kwiatkowski
,
F.
Mariam
,
F.
Merrill
, and
A.
Saunders
, “
Charged particle radiography
,”
Rep. Prog. Phys.
4
,
046301 1
26
(
2013
).
5.
F.
Merrill
, “
Imaging with penetrating radiation for the study of small dynamic physical processes
,”
Laser Part. Beams
33
,
425
431
(
2015
).
6.
A. D.
Dymnikov
and
S. Y.
Yavor
, “
[Four quadrupole lenses as an analogue of an axially symmetric system.]
,”
Sov. Phys. Tech. Phys.
8
,
639
643
(
1963
).
7.
K.
Makino
and
M.
Berz
, “
Cosy infinity version 9
,”
Nucl. Instrum. Methods Phys. Res., Sect. A
558
,
346
350
(
2006
).
8.
James
Thomas Volk
, “
Summary of radiation damage studies on rare earth permanent magnets
,” in
Proceedings of the APS/DPF/DPB Summer Study on the Future of Particle Physics (Snowmass 2001), Snowmass, Colorado, 30 June–21 Jul 2001, eConf
(
2001
), Vol. C010630, p.
T207
.
9.
M.
Schanz
, “
Protoneninduzierte Strahlungsschäden an NdFeB Permanentmagneten
,” Bachelor’s thesis,
TU Darmstadt
,
2013
.
10.
C.
Danly
,
F.
Merrill
,
D.
Barlow
, and
F.
Mariam
, “
Nonuniform radiation damage in permanent magnet quadrupoles
,”
Rev. Sci. Instrum.
85
,
083305-1–083305-
5
(
2014
).
11.
Z.
Li
,
Y.
Jia
,
R.
Liu
,
Y.
Xu
,
G.
Wang
, and
X.
Xia
, “
Investigation on demagnetization of Nd2Fe14B permanent magnets induced by irradiation
,”
Nucl. Instrum. Methods Phys. Res., Sect. B
413
,
68
74
(
2017
).
12.
K.
Halbach
, “
Design of permanent multipole magnets with oriented rare earth cobalt material
,”
Nucl. Instrum. Methods
169
,
1
10
(
1980
).
13.
A.
Kantsyrev
,
V.
Skachkov
,
V.
Panyushkin
,
A.
Golubev
,
A.
Bogdanov
,
A.
Bakhmutova
,
E.
Ladygina
,
N.
Markov
,
O.
Sergeeva
,
V.
Skachkov
,
A.
Semennikov
,
V.
Turtikov
,
D. V.
Varentsov
,
L.
Shestov
,
M.
Rodionova
,
M.
Endres
,
P. M.
Lang
,
D. H. H.
Hoffmann
, and
S.
Udrea
, “
Quadrupole lenses on the basis of permanent magnets for a PRIOR proton microscope prototype
,”
Instrum. Exp. Tech.
59
,
712
723
(
2016
).
14.
S.
Agostinelli
,
J.
Allison
 et al, “
Geant4—A simulation toolkit
,”
Nucl. Instrum. Methods Phys. Res., Sect. A
506
,
250
303
(
2003
).
15.
C.
Danly
, “
Radiation damage in permanent magnet lenses
,” M.S. thesis,
The University of New Mexico
,
2014
.
16.
See www.femm.info for Finite Element Method magnetics (FEMM), 2010.
17.
T.
Lienig
, “
Investigation of magnetic and microstructural properties of proton irradiated NdFeB
,” Bachelor’s thesis,
TU Darmstadt
(
2014
).
18.
Magnetic materials—Part 8-1: Specifications for individual materials—Magnetically hard materials
,”
International Electrotechnical Commission
,
2015
.
19.
J. F.
Ziegler
,
M. D.
Ziegler
, and
J. P.
Biersack
, “
SRIM—The stopping and range of ions in matter
,”
Nucl. Instrum. Methods Phys. Res., Sect. B
268
,
1818
1823
(
2010
).
20.
O.
Gutfleisch
, “
Controlling the properties of high energy density permanent magnetic materials by different processing routes
,”
J. Phys. D: Appl. Phys.
33
,
R157
R172
(
2000
).
21.
M.
Sagawa
,
S.
Fujimura
,
N.
Togawa
,
H.
Yamamoto
, and
Y.
Matsuura
, “
New material for permanent-magnets on a base of Nd and Fe
,”
J. Appl. Phys.
55
,
2083
2087
(
1984
).
22.
K.
Khlopkov
,
O.
Gutfleisch
,
D.
Eckert
,
D.
Hinz
,
B.
Wall
,
W.
Rodewald
,
K.-H.
Müller
, and
L.
Schultz
, “
Local texture in Nd-Fe-B sintered magnets with maximised energy density
,”
J. Alloys Compd.
365
,
259
265
(
2004
).
23.
F.
Vial
,
F.
Joly
,
E.
Nevalainen
,
M.
Sagawa
,
K.
Hiraga
, and
K.
Park
, “
Improvement of coercivity of sintered NdFeB permanent magnets by heat treatment
,”
J. Magn. Magn. Mater.
242
,
1329
1334
(
2002
).
24.
T.
Woodcock
,
F.
Bittner
,
T.
Mix
,
K.
Mueller
,
S.
Sawatzki
, and
O.
Gutfleisch
, “
On the reversible and fully repeatable increase in coercive field of sintered Nd-Fe-B magnets following post sinter annealing
,”
J. Magn. Magn. Mater.
360
,
157
164
(
2014
).
25.
T.
Woodcock
,
Y.
Zhang
,
G.
Hrkac
,
G.
Ciuta
,
N.
Dempsey
,
T.
Schrefl
,
O.
Gutfleisch
, and
D.
Givord
, “
Understanding the microstructure and coercivity of high performance NdFeB-based magnets
,”
Scr. Mater.
67
,
536
541
(
2012
).
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