Inverse-collimated proton radiography for imaging thin materials.
Relativistic, magnetically focused proton radiography was invented at Los Alamos National Laboratory using the 800 MeV LANSCE beam and is inherently well-suited to imaging dense objects, at areal densities >20 g cm-2. However, if the unscattered portion of the transmitted beam is removed at the Fourier plane through inverse-collimation, this system becomes highly sensitive to very thin media, of areal densities <100 mg cm-2. Here, this inverse-collimation scheme is described in detail and demonstrated by imaging Xe gas with a shockwave generated by an aluminum plate compressing the gas at Mach 8.8. With a 5-mrad inverse collimator, an areal density change of just 49 mg cm-2across the shock front is discernible with a contrast-to-noise ratio of 3. Geant4 modeling of idealized and realistic proton transports can guide the design of inverse-collimators optimized for specific experimental conditions and show that this technique performs better for thin targets with reduced incident proton beam emittance. This work increases the range of areal densities to which the system is sensitive to span from ∼25 mg cm-2to 100 g cm-2, exceeding three orders of magnitude. This enables the simultaneous imaging of a dense system as well as thin jets and ejecta material that are otherwise difficult to characterize with high-energy proton radiography.
Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Matthew S
MS
Freeman
Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Jason
J
Allison
Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Malcolm
M
Andrews
Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Eric
E
Ferm
Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
John J
JJ
Goett
Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Kris
K
Kwiatkowski
Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Julian
J
Lopez
Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Fesseha
F
Mariam
Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Mark
M
Marr-Lyon
Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Michael
M
Martinez
Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Jason
J
Medina
Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Patrick
P
Medina
Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Frank E
FE
Merrill
Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Chris L
CL
Morris
Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Matthew M
MM
Murray
Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Paul
P
Nedrow
Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Levi P
LP
Neukirch
Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Katherine
0000000324255086
K
Prestridge
Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Paolo
P
Rigg
Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Alexander
A
Saunders
Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Tamsen
T
Schurman
Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Amy
A
Tainter
Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Frans
F
Trouw
Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Dale
0000000262655016
D
Tupa
Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Josh
J
Tybo
Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Wendy
W
Vogan-McNeil
Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Carl
C
Wilde