Pith. sign in

REVIEW 1 major objections 6 minor 1 cited by

Focusing of Relativistic Electron Beams With Permanent Magnetic Solenoid

T0 review · 1 major / 6 minor · reviewed 2026-08-16 · deepseek-v4-flash

Pith's one-line read A dual-ring permanent magnetic solenoid focuses 7.1 MeV electron beams to an 8.4 cm focal length, matching simulation.

desk verdict A compact dual-ring permanent magnet solenoid is measured to focus 7.1 MeV electrons to an 8.4 cm focal length; the result is credible, with minor overclaims in the abstract and a few soft spots in uncertainty reporting. read the letter →

arxiv 2504.21121 v1 pith:C4WMI6UX submitted 2025-04-29 physics.acc-ph

classification physics.acc-ph PACS 41.85.Lc29.27.-a
keywords permanentmagneticsolenoidradiallymagnetizedringelectronbeamfocusingMeVbeamsultrafastdiffractioninverseComptonscatteringfieldcharacterizationfocallength
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The reading

The paper claims that a passive, permanent-magnet lens—two oppositely magnetized neodymium rings—can focus a 7.1 MeV electron beam to a focal length of 8.4 ± 0.1 cm, with no power supply and no cooling. That matters because strong focusing of relativistic electron beams normally requires bulky electromagnets or superconducting solenoids, which are hard to fit into compact X-ray sources, MeV microscopes, and ultrafast electron diffraction beamlines. The authors build the lens, characterize its magnetic field, test it on a high-brightness photoinjector, and show that the measured beam transport matches particle-tracking simulations. They then argue that the same lens can magnify diffraction angles and produce sub-10-micrometer spots for Compton scattering and other microfocus applications.

What carries the argument

The central object is the radially magnetized permanent magnetic solenoid in a dual-ring configuration: two neodymium rings, one magnetized inward and one outward, separated by a tunable gap. The on-axis field is built from the surface-current disk formula, $B_z = B_{z,disk}(z+l_1)+B_{z,disk}(z-l_1)-B_{z,disk}(z+l_1+L)-B_{z,disk}(z-l_1-L)$, producing a 1 T peak field in a 1.2 cm bore. Because the integral of the on-axis field vanishes, the lens imparts no net Larmor rotation. The focal length is extracted from the linear transfer matrix via $f = -1/R_{21}$, and the spherical aberration from $C_{s,x} = U_{1222}/R_{11}$; these quantities are computed from field maps reconstructed with generalized-gradient expansions and then tracked with particle-tracking simulations.

What would settle it

Measure the beam spot at the nominal focus with a knife-edge or wire scanner, independently of the camera-based fitting and field reconstruction. If the waist does not sit 8.4 cm from the magnet center or the RMS size does not shrink to the predicted tens-of-micrometer level, the reconstructed-field model is wrong.

Watch

Extended reading notes

Core claim

The paper establishes experimentally that a dual-ring radially magnetized permanent magnetic solenoid (RM-PMS) can focus a 7.1 MeV electron beam with a measured focal length of 8.4 ± 0.1 cm, consistent with simulation predictions. The transport matrix element $R_{21}$ was measured to be -11.9 ± 0.3 m$^{-1}$, giving this focal length through $f = -1/R_{21}$. Beam images on a YAG screen show the RMS size dropping from roughly 215 by 315 micrometers to 35 by 25 micrometers when the lens is inserted. The same design, with a 4.2 cm focal length at 4 MeV, is then used in simulations of angular magnification for ultrafast electron diffraction and of tight focusing for inverse Compton sources.

Load-bearing premise

The result rests on the assumption that the measured three-dimensional magnetic field map of the assembled lens, including small manufacturing imperfections in its eight wedge pieces, is an accurate portrait of the real magnet during the beam tests; if those imperfections are larger than characterized, the beam will be steered and distorted more than predicted and the application studies will overstate performance.

Editorial extensions

If this is right

  • A single passive insert can replace an electromagnet for sub-10 cm focusing of 4 to 7 MeV beams, eliminating the power and cooling needs of conventional solenoids.
  • Because the on-axis field integral vanishes, the RM-PMS imparts no net Larmor rotation; using it as both objective and eyepiece in a UED lens stack cancels rotation and simplifies alignment.
  • In the bilayer WS2 diffraction simulation, the PMS eyepiece improves reciprocal-space resolution from 0.083 Å⁻¹ to 0.05 Å⁻¹.
  • The measured reduction from roughly 215 by 315 micrometers to 35 by 25 micrometers RMS beam size demonstrates the focusing capability at 7.1 MeV, and the envelope fit yields horizontal and vertical geometric emittances of 59 and 82 nanometers.
  • For tight focusing, the transfer-map analysis predicts sub-10-micrometer waists for low-emittance beams, with an optimal initial beam size set by the balance between emittance and third-order aberration $U_{2111}$.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • I infer that the same dual-ring geometry could be pushed to higher beam energies by increasing the ring separation, stacking additional rings, or using stronger rare-earth grades; the paper gives the scaling relationships but does not test these variants.
  • I infer that the residual x-y coupling ($R_{31}$, $R_{41}$) from the eight wedge sectors will be the main quality limiter for sub-micron focusing, and a monolithic hot-pressed ring would remove it at the cost of fabrication flexibility.
  • A natural next experiment is an independent absolute spot-size measurement at the focus using a knife-edge or wire scanner; the paper validates the transport matrix but does not compare an absolute focal-plane spot size against simulation.
  • I infer the angular-magnification application could be validated in an existing MeV-UED endstation by imaging a known polycrystalline sample with and without the PMS eyepiece; the paper demonstrates this application by simulation only.
Share X Bluesky LinkedIn Reddit HN

Signed reviews

No signed human review yet.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

1 major / 6 minor

Summary. The manuscript reports the design, fabrication, magnetic-field characterization, and electron-beam test of a compact dual-ring radially magnetized permanent magnetic solenoid (PMS) for focusing multi-MeV electron beams. The authors derive an analytical field model, optimize the ring geometry for a 4 MeV design, and characterize a prototype with Hall-probe scans processed via generalized-gradient expansions. Beam tests at 7.1 MeV on the UCLA Pegasus beamline yield a focal length f = 8.4 cm, determined both from the axial beam-size minimum and from the mixed derivative of the beam centroid with respect to lens transverse and longitudinal positions (R21 = -11.9 m^-1). GPT simulations using the measured field maps give the same R21. Two applications are analyzed by simulation: angular magnification in MeV-UED and tight focusing for inverse Compton scattering.

Significance. If the central result is correct, the paper demonstrates a practical, power-free, 1 T-class solenoid lens with sub-10 cm focal length for MeV beams, a capability relevant to compact UED and photon-source beamlines. The main strengths are the direct centroid-scan measurement of R21, which is insensitive to incoming-beam Twiss parameters, the independent Hall-probe field characterization, and the quantitative agreement between experiment and GPT/COSY simulations. The measured minimum beam size of about 23-35 um and the agreement in R21 support the central claim. The main limitations are that the application predictions and the 'small spherical aberrations' claim are simulation-based, and the GPT beam-size comparison in Fig. 6(c) is not fully independent because the Twiss parameters were matched to the same data. The stress-test concern about generalized-gradient field maps does not land for the focal-length measurement itself, since R21 is extracted from centroid scans rather than from the field maps.

major comments (1)
  1. [Section III, Fig. 6(c)] The GPT curves in Fig. 6(c) are not an independent predictive test of the beam-size evolution because the Twiss parameters at the PMS entrance were obtained by numerically matching the GPT simulation to the same measured beam-size data. The text should state explicitly that this agreement is by construction, or provide an independent validation of the Twiss parameters. This does not undermine the R21-based focal-length measurement, which is independent of the incoming Twiss parameters, but it should be corrected to avoid overstating the validation.
minor comments (6)
  1. [Section III, Table II] The quoted focal-length uncertainty f = 8.4 ± 0.1 cm is not the propagated value from σ_R21 = 0.3 m^-1. Using f = -1/R21, σ_f = f^2 σ_R21 ≈ 0.21 cm. Please recompute the uncertainty or justify a smaller value from correlated fit errors; the qualitative conclusion is unaffected.
  2. [Abstract and Section II] The phrase 'small spherical aberrations' in the abstract is not supported by a direct measurement; the evidence is the simulated U2111 coefficient and beam-size modeling. Recommend rephrasing as 'predicted small spherical aberrations' or adding an experimental characterization of the aberration.
  3. [Section IV.B, Eq. (15)] Equation (15) assumes a Gaussian beam with uncorrelated x0 and x0' and includes only the U2111 x^3 term of the nonlinear map. Please state these assumptions explicitly and note that a full solenoid third-order map also contains x y^2 type terms; the estimate is then clearly an approximation.
  4. [Section IV.A, Eq. (11)] The magnification estimate of 12 is not derived in the text. Please specify the values of le, fobj, and feye used in Eq. (11) and state how the finite detector size limits the field of view.
  5. [Throughout] There are several typographical errors: 'averge' in Section III, 'downtream' in the Table II caption, 'beams sizss' in the Fig. 9 caption, and 'coordinate with converted' in Fig. 8(c). A careful proofreading pass is needed.
  6. [References] Reference [30] is a product webpage and [14] is a Master's thesis; while acceptable in context, consider supplementing with peer-reviewed sources where available.

Circularity Check

0 steps flagged · score 0.0 of 10

No significant circularity: the focal length is directly measured from centroid scans and independently cross-checked by design-code and measured-field simulations.

full rationale

The central claim, f = 8.4 ± 0.1 cm, is obtained experimentally from the transport-matrix centroid scan in Section III, using R21 = ∂X∂Z⟨x1⟩ from polynomial fits to the measured centroids (Eqs. 4–9 and Table II). This quantity is a direct measurement and is not fitted from the field model or from the GPT simulation. The agreement with simulation is an independent cross-check: the design prediction in Table I is computed from the analytical surface-current field model (Eq. 3) via COSY Infinity, and the GPT simulation in Section III uses the independently measured Hall-probe field maps reconstructed via generalized gradients (Section II.B). Neither simulation uses the measured focal length or measured R21 as an input. The Twiss parameters mentioned in Section III are matched to reproduce the measured beam-size evolution, but they only set initial conditions and do not enter the centroid cross-derivative R21 from which the focal length is derived. Residual x-y coupling (R31, R41) is acknowledged as coming from magnetization imperfections and affects application projections, but it does not feed back into the measured focal length. The one self-citation ([26]) supports a background statement about magnetization uniformity and is not load-bearing. A separate statistical note is that propagating σ_R21 = 0.3 m^-1 through f = −1/R21 gives σ_f ≈ 0.2 cm rather than 0.1 cm, but this is a minor uncertainty-estimation point, not a circularity. Overall the derivation is self-contained and externally grounded; no circular step was identified.

Assumptions & free parameters 3 free parameters · 5 assumptions · 0 invented entities

The central claims rely on standard magnetostatic formulas, beam-optics models, and commercial simulation codes, plus hand-chosen geometric design parameters. The only data-fitted quantities are the incoming beam Twiss parameters and emittance used as simulation initial conditions. No new physical entities are invented.

free parameters (3)
  • PMS ring geometry (Ri, Ro, L, l1) = 0.6 cm, 3.5 cm, 1.6 cm, 0.935 cm
    Design parameters selected by hand or optimization to minimize focal length at 4 MeV subject to holder and stage constraints (Table I). They set the field profile through Eq. (3).
  • Magnet remanence Br = 1.32 T
    Vendor-quoted NdFeB remanence used in the analytical field model. Hall probe measurements confirmed peak fields within 0.01 T, so it is checked but not independently derived.
  • Incoming beam Twiss parameters and geometric emittance = εx=59 nm, εy=82 nm; αx=0.6, βx=0.55 m, αy=0.02, βy=1.2 m
    Numerically matched to measured beam-size evolution in GPT (Section III). These are fitted initial conditions for the simulation comparison, not parameters of the lens.
assumptions (5)
  • standard math Surface-current model for on-axis field of radially magnetized permanent rings (Eqs. 1-3)
    Borrowed from Peng et al. [20]; validated by Hall probe and analytical comparisons.
  • standard math Paraxial solenoid focusing formula 1/f = (e/(2pz))^2 ∫ Bz^2 dz
    Used to compute focal lengths from field integrals for design scans (Section II.A).
  • domain assumption Transfer maps from cosy infinity and GPT particle tracking correctly include nonlinear effects and measured multipole fields
    The paper relies on these commercial codes for focal length and aberration predictions; no independent analytic derivation of U2111 for the assembled magnet is given beyond Green's function agreement.
  • domain assumption Eight-segment wedge assembly produces negligible multipoles under ideal conditions
    Stated in Section II.A; the authors mitigate through sorting and pairing and measured small R31/R41, but the ideal uniformity is an assumption.
  • standard math Gaussian beam sixth-moment identity <x0^6>=15σ^6 and envelope equation for waist size
    Used in Eq. (15) and Eq. (12) for the tight-focusing application estimate.

how reviews work

0 comments
Cite this review

Pith. "Pith review of Focusing of Relativistic Electron Beams With Permanent Magnetic Solenoid." pith.science (2026). https://pith.science/paper/C4WMI6UX

@misc{pith2026250421121,
  author       = {Pith},
  title        = {Pith review of: Focusing of Relativistic Electron Beams With Permanent Magnetic Solenoid},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/C4WMI6UX}},
  note         = {Machine review of arXiv:2504.21121}
}
read the original abstract

Achieving strong focusing of MeV electron beams is a critical requirement for advanced beam applications such as compact laboratory X-ray sources, high gradient accelerators, and ultrafast electron scattering instrumentation. To address these needs, a compact radially magnetized permanent magnetic solenoid (PMS) has been designed, fabricated, and tested. The solenoid provides a compact and inexpensive solution for delivering high axial magnetic fields (1 Tesla) to focus MeV electron beams. Field characterization of the solenoid demonstrates excellent agreement with analytical models, validating the PMS design. The electron beam test employs a high-brightness photoinjector to study the focusing properties of the PMS. The results indicate a focal length of less than 10 cm and a significant reduction in beam size with small spherical aberrations. Two application cases are evaluated: angular magnification in ultrafast electron diffraction setups and strong focusing for Compton scattering or other microfocus uses.

Figures

Figures reproduced from arXiv: 2504.21121 by the authors.

Figure 1
Figure 1. FIG. 1. (a) Cartoon design of a single RM-PMS ring. The [PITH_FULL_IMAGE:figures/full_fig_p002_1.png] view at source ↗
Figure 2
Figure 2. FIG. 2. (a) Schematic of dual RM-PMS ring arrangement. (b) [PITH_FULL_IMAGE:figures/full_fig_p002_2.png] view at source ↗
Figure 3
Figure 3. FIG. 3. Kick exerted on electron beam by PMS fringe fields [PITH_FULL_IMAGE:figures/full_fig_p003_3.png] view at source ↗
Figures from the paper (6 more)
Figure 4
Figure 4. Figure 4: FIG. 4. (a) Fully assembled dual RM-PMS ring. (b) On-axis magnetic field of the dual RM-PMS ring comparing a superposition [PITH_FULL_IMAGE:figures/full_fig_p004_4.png]
Figure 5
Figure 5. Figure 5: FIG. 5. (a) Vertical and (b) horizontal dipole components [PITH_FULL_IMAGE:figures/full_fig_p004_5.png]
Figure 6
Figure 6. Figure 6: FIG. 6. Measured electron beam profiles on the YAG screen when PMS is retracted (a) and inserted (b) in beam path. Inset in [PITH_FULL_IMAGE:figures/full_fig_p005_6.png]
Figure 7
Figure 7. Figure 7: FIG. 7. Linear transport measurements: (a) horizontal scan of the PMS lens position results in the image on the final screen [PITH_FULL_IMAGE:figures/full_fig_p006_7.png]
Figure 8
Figure 8. Figure 8: FIG. 8. Simulated diffraction pattern of bilayer WS [PITH_FULL_IMAGE:figures/full_fig_p007_8.png]
Figure 9
Figure 9. Figure 9: FIG. 9. Evolution of beam size at focal point vs. beam size at [PITH_FULL_IMAGE:figures/full_fig_p008_9.png]

Discussion (0). Continue with ORCID to comment.

Forward citations

Cited by 1 Pith paper

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score. Full citation record

  1. Shallow Angle Inverse Compton Scattering

    physics.acc-ph 2025-09 conditional novelty 7.0 of 10

    First experimental observation of shallow-angle inverse Compton scattering at 5.8 degrees, with measured polarization suppression matching the predicted relativistic Brewster condition.

Reference graph

Works this paper leans on

40 extracted references · 40 canonical work pages · cited by 1 Pith paper

  1. [1]

    3D field mapping : 3D Hall probe scans (0.4 cm×0.4 cm×40 cm volume around mechanical and field centers) were performed for all RM-PMS rings

  2. [2]

    Generalized gradient computation: The mea- sured field maps around mechanical centers were processed to compute the generalized gradient ex- pansion of the magnetic fields [27]. This technique expresses the fields in terms of z-dependent mul- tipoles coefficients and their derivatives (pseudo- multipoles) and is derived from the measured (Bx,By,Bz) compon...

  3. [3]

    Numerical optimization : Generalized gradient representation of each RM-PMS is numerically ro- tated and paired with a counterpart of opposite magnetization for all possible permutations. Trans- fer matrices of the combined fields were calculated in elegant [28], optimizing rotation angle and combination to minimize deviations in R21 and R43 (astigmatism)...

  4. [4]

    In principle, step 4 can be iterated to refine focusing performance (stigmatic focusing and zero kick) based on measured fields

    Assembly and validation : Selected pairs were physically rotated, assembled, followed by a 3D Hall probe scan to verify the field components after combination. In principle, step 4 can be iterated to refine focusing performance (stigmatic focusing and zero kick) based on measured fields. However, the strong axial attraction forces between oppositely magne...

  5. [5]

    As illustrated in Fig

    Adding magnetic optics downstream of the sample can remove thex0 term and increase the effective camera length (transfer matrix element R12). As illustrated in Fig. 8, an objective lens (OL) of focal length fobj maps the divergence into spatial offsets at its back focal plane (BFP). The virtual image is then magnified by an eye- piece lens of focal length...

  6. [6]

    The particle receives a focusing kick when passing through the mag- net, x′ 1 =x′ 0 +R21xo +U2111x3

    at the magnet entrance. The particle receives a focusing kick when passing through the mag- net, x′ 1 =x′ 0 +R21xo +U2111x3

  7. [7]

    For beams with higher energy, U2111 can also be calculated from the field profile following Eq

    (13) The matrix element R21 can be approximated by −1/f, while U2111, the higher order term associated with the the nonlinear aberration, can be computed exactly with cosy infinity or Green’s function methods [31]. For beams with higher energy, U2111 can also be calculated from the field profile following Eq. (6) in [32] under a constant-radius approximat...

  8. [8]

    (14) 250 500 750 10000 5 10 15 20x, f ( m) (a) Eq.12 Eq.15 GPT w/o SC GPT w/ SC 250 500 750 1000 x, 0 ( m) 0 5 10 15 20x, f ( m) (b) x=0.2 m x=0.5 m x=1.0 m FIG. 9. Evolution of beam size at focal point vs. beam size at lens entrance. (a) Comparison of waist sizes calculated with different methods for a beam with 0.2 µm emittance. (b) beam sizss at focal ...

Show all 40 references
  1. [9]

    Advances in bright electron sources,

    P. Musumeci, J. Giner Navarro, J. Rosenzweig, L. Cultr- era, I. Bazarov, J. Maxson, S. Karkare, and H. Padmore, “Advances in bright electron sources,” Nucl. Instrum. Methods Phys. Res., Sect. A, vol. 907, pp. 209–220, 2018

  2. [10]

    Ultrafast elec- tron diffraction: Visualizing dynamic states of matter,

    D. Filippetto, P. Musumeci, R. K. Li, B. J. Siwick, M. R. Otto, M. Centurion, and J. P. F. Nunes, “Ultrafast elec- tron diffraction: Visualizing dynamic states of matter,” Rev. Mod. Phys., vol. 94, p. 045004, Dec 2022

  3. [11]

    Compact x-ray source based on burst-mode inverse compton scat- tering at 100 khz,

    W. S. Graves, J. Bessuille, P. Brown, S. Carbajo, V. Dol- gashev, K.-H. Hong, E. Ihloff, B. Khaykovich, H. Lin, K. Murari, E. A. Nanni, G. Resta, S. Tantawi, L. E. Zapata, F. X. K¨ artner, and D. E. Moncton, “Compact x-ray source based on burst-mode inverse compton scat- terin...

  4. [12]

    Dielectric laser accelerators,

    R. J. England, R. J. Noble, K. Bane, D. H. Dowell, C.- K. Ng, J. E. Spencer, S. Tantawi, Z. Wu, R. L. Byer, E. Peralta, K. Soong, C.-M. Chang, B. Montazeri, S. J. Wolf, B. Cowan, J. Dawson, W. Gai, P. Hommelhoff, Y.-C. Huang, C. Jing, C. McGuinness, R. B. Palmer, B. Naranjo, J...

  5. [13]

    Segmented terahertz electron ac- celerator and manipulator (steam),

    D. Zhang, A. Fallahi, M. Hemmer, X. Wu, M. Fakhari, Y. Hua, H. Cankaya, A.-L. Calendron, L. E. Zapata, N. H. Matlis, et al. , “Segmented terahertz electron ac- celerator and manipulator (steam),” Nature Photonics , vol. 12, no. 6, pp. 336–342, 2018

  6. [14]

    Single-shot mev transmis- sion electron microscopy with picosecond temporal reso- lution,

    R. K. Li and P. Musumeci, “Single-shot mev transmis- sion electron microscopy with picosecond temporal reso- lution,” Phys. Rev. Appl. , vol. 2, p. 024003, Aug 2014

  7. [15]

    Demonstration of single- shot high-quality cascaded high-energy-electron radiog- raphy using compact imaging lenses based on permanent- magnet quadrupoles,

    Z. Zhou, Y. Fang, H. Chen, Y. Wu, Y. Du, L. Yan, C. Tang, and W. Huang, “Demonstration of single- shot high-quality cascaded high-energy-electron radiog- raphy using compact imaging lenses based on permanent- magnet quadrupoles,” Phys. Rev. Appl. , vol. 11, no. 3, p. 034068, 2019

  8. [16]

    High en- 10 ergy electron diffraction instrument with tunable camera length,

    P. Denham, Y. Yang, V. Guo, A. Fisher, X. Shen, T. Xu, R. J. England, R. K. Li, and P. Musumeci, “High en- 10 ergy electron diffraction instrument with tunable camera length,” Structural Dynamics , vol. 11, p. 024302, Mar. 2024

  9. [17]

    Adjustable, short focal length permanent-magnet quadrupole based electron beam fi- nal focus system,

    J. K. Lim, P. Frigola, G. Travish, J. B. Rosenzweig, S. G. Anderson, W. J. Brown, J. S. Jacob, C. L. Robbins, and A. M. Tremaine, “Adjustable, short focal length permanent-magnet quadrupole based electron beam fi- nal focus system,” Phys. Rev. ST Accel. Beams , vol. 8, p. 0724...

  10. [18]

    Demonstration of Single-Shot Picosecond Time- Resolved MeV Electron Imaging Using a Compact Per- manent Magnet Quadrupole Based Lens,

    D. Cesar, J. Maxson, P. Musumeci, Y. Sun, J. Har- rison, P. Frigola, F. O’Shea, H. To, D. Alesini, and R. Li, “Demonstration of Single-Shot Picosecond Time- Resolved MeV Electron Imaging Using a Compact Per- manent Magnet Quadrupole Based Lens,” Phys. Rev. Lett., vol. 117, p. ...

  11. [19]

    Permanent magnet- based quadrupoles for plasma acceleration sources,

    A. Ghaith, D. Oumbarek, C. Kit´ egi, M. Vall´ eau, F. Marteau, and M.-E. Couprie, “Permanent magnet- based quadrupoles for plasma acceleration sources,” In- struments, vol. 3, no. 2, p. 27, 2019

  12. [20]

    Design of compact ultrafast microscopes for single-and multi-shot imaging with mev electrons,

    W. Wan, F.-R. Chen, and Y. Zhu, “Design of compact ultrafast microscopes for single-and multi-shot imaging with mev electrons,” Ultramicroscopy, vol. 194, pp. 143– 153, 2018

  13. [21]

    Wide aperture permanent mag- net solenoid,

    B. Hoff, C. Chen, J. Horwath, M. Haworth, P. Mar- dahl, and S. Heidger, “Wide aperture permanent mag- net solenoid,” Journal of Applied Physics, vol. 111, no. 7, 2012

  14. [22]

    Design of permanent magnetic solenoids for REGAE,

    T. Gehrke, “Design of permanent magnetic solenoids for REGAE,” Master’s thesis, 2013

  15. [23]

    Design and characterization of permanent magnetic solenoids for REGAE,

    M. Hachmann, K. Fl¨ ottmann, T. Gehrke, and F. Mayet, “Design and characterization of permanent magnetic solenoids for REGAE,” Nucl. Instrum. Methods Phys. Res., Sect. A, vol. 829, pp. 270–273, Sept. 2016

  16. [24]

    Supercon- ducting lens design,

    G. Lefranc, E. Knapek, and I. Dietrich, “Supercon- ducting lens design,” Ultramicroscopy, vol. 10, no. 1-2, pp. 111–123, 1982

  17. [25]

    High-brilliance, high-flux compact inverse compton light source,

    K. E. Deitrick, G. A. Krafft, B. Terzi´ c, and J. R. Delayen, “High-brilliance, high-flux compact inverse compton light source,” Phys. Rev. Accel. Beams, vol. 21, p. 080703, Aug 2018

  18. [26]

    Ultrafast relativistic elec- tron nanoprobes,

    F. Ji, D. B. Durham, A. M. Minor, P. Musumeci, J. G. Navarro, and D. Filippetto, “Ultrafast relativistic elec- tron nanoprobes,” Communications Physics, vol. 2, no. 1, p. 54, 2019

  19. [27]

    Progress on pulsed elec- tron beams for radiation effects characterization of elec- tronics,

    A. Kulkarni and P. Musumeci, “Progress on pulsed elec- tron beams for radiation effects characterization of elec- tronics,” Proc. IPAC’24, pp. 3688–3691, 2024

  20. [28]

    Axial magnetic field produced by axially and radially magnetized permanent rings,

    Q. Peng, S. McMurry, and J. Coey, “Axial magnetic field produced by axially and radially magnetized permanent rings,” Journal of Magnetism and Magnetic Materials , vol. 268, pp. 165–169, Jan. 2004

  21. [29]

    Computational aspects of optics design and simulation: Cosy infinity,

    M. Berz, “Computational aspects of optics design and simulation: Cosy infinity,” Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment , vol. 298, no. 1, pp. 473–479, 1990

  22. [30]

    A First- and Second-Order Matrix Theory for the Design of Beam Transport Systems and Charged Particle Spectrometers,

    K. Brown, “A First- and Second-Order Matrix Theory for the Design of Beam Transport Systems and Charged Particle Spectrometers,” Tech. Rep. SLAC-r-075, Stan- ford Linear Accelerator Center, June 1982

  23. [31]

    A three- dimensional magnetostatics computer code for inser- tion devices,

    O. Chubar, P. Elleaume, and J. Chavanne, “A three- dimensional magnetostatics computer code for inser- tion devices,” Journal of Synchrotron Radiation , vol. 5, pp. 481–484, May 1998

  24. [32]

    General Particle Tracer

    “General Particle Tracer.” https://www.pulsar.nl/ gpt/index.html

  25. [33]

    Hot deformation of nanocrystalline nd-fe- b alloys,

    W. Gr¨ unberger, D. Hinz, A. Kirchner, K.-H. M¨ uller, and L. Schultz, “Hot deformation of nanocrystalline nd-fe- b alloys,” Journal of Alloys and Compounds , vol. 257, no. 1-2, pp. 293–301, 1997

  26. [34]

    Field charac- terization of axially and radially magnetized neodymium rings,

    T. Xu, S. D. Anderson, and R. J. England, “Field charac- terization of axially and radially magnetized neodymium rings,” in Proc. IPAC’24, 2024

  27. [35]

    Accurate computation of transfer maps from magnetic field data,

    M. Venturini and A. J. Dragt, “Accurate computation of transfer maps from magnetic field data,” Nucl. Instrum. Methods Phys. Res., Sect. A, vol. 437, pp. 387–392, 1999

  28. [36]

    Elegant: A flexible sdds-compliant code for accelerator simulation,

    M. Borland, “Elegant: A flexible sdds-compliant code for accelerator simulation,” tech. rep., Argonne National Lab., IL (US), 2000

  29. [37]

    Mega-electron-volt ultrafast electron diffraction at slac national accelerator laboratory,

    S. Weathersby, G. Brown, M. Centurion, T. Chase, R. Coffee, J. Corbett, J. Eichner, J. Frisch, A. Fry, M. G¨ uhr,et al. , “Mega-electron-volt ultrafast electron diffraction at slac national accelerator laboratory,” Re- view of Scientific Instruments , vol. 86, no. 7, 2015

  30. [38]

    https://www.magnet4less.com/rare-earth-magnets- n45-3-4-in-od-x-1-4-in-id-x-1-4-in-neodymium-ring

    “https://www.magnet4less.com/rare-earth-magnets- n45-3-4-in-od-x-1-4-in-id-x-1-4-in-neodymium-ring.” product webpage of AM-PMS

  31. [39]

    Space-charge aberra- tions in single-shot time-resolved transmission electron microscopy,

    P. Denham and P. Musumeci, “Space-charge aberra- tions in single-shot time-resolved transmission electron microscopy,” Phys. Rev. Appl. , vol. 15, p. 024050, Feb 2021

  32. [40]

    Nonlinear Optics of Solenoid Magnets,

    S. M. Lund, “Nonlinear Optics of Solenoid Magnets,” in Proc. IPAC’15, pp. 4048–4050, JACoW Publishing, Geneva, Switzerland

Pith tools

Reviewed August 16, 2026 · model on record in the stance chip above.