From grames at jlab.org Thu May 1 10:24:17 2025 From: grames at jlab.org (Joe Grames) Date: Thu, 1 May 2025 14:24:17 +0000 Subject: [PEPPo] interesting solenoid article Message-ID: Hi, I thought I would pass along this article, perhaps especially interesting to those who of us who often used solenoids in the keV-MeV beam energy. Joe -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: 2504.21121v1.pdf Type: application/pdf Size: 1829713 bytes Desc: 2504.21121v1.pdf URL: From rarimmer at jlab.org Thu May 1 10:39:43 2025 From: rarimmer at jlab.org (Robert Rimmer) Date: Thu, 1 May 2025 14:39:43 +0000 Subject: [PEPPo] interesting solenoid article In-Reply-To: References: Message-ID: thanks Joe, this is interesting and timely. I was thinking it could be useful for our compact accelerators. I know periodic permanent magnetic focusing has been used for years on vacuum tubes and that KEK had installed weak PM "solenoids" in certain locations to counter electron cloud in super KEKB. I guess old CRT TV's also used permanent magnet beam focusing too. I guess the main concern for the positron target would be radiation hardness. I remember there was some interesting work done in the 90's (?) on "adjustable" permanent magnets using rotating blocks or magnetic material to mechanically adjust field strength. I think those may have been modified Halbach magnets. I wonder if anyone has made such an adjustable PM solenoid? Bob. ________________________________ From: PEPPo on behalf of Joe Grames via PEPPo Sent: Thursday, May 1, 2025 10:24 AM To: ACCCIS Staff ; peppo at jlab.org ; Reza Kazimi ; Yan Wang ; Matthew Poelker Subject: [PEPPo] interesting solenoid article Hi, I thought I would pass along this article, perhaps especially interesting to those who of us who often used solenoids in the keV-MeV beam energy. Joe -------------- next part -------------- An HTML attachment was scrubbed... URL: From benesch at jlab.org Thu May 1 10:56:37 2025 From: benesch at jlab.org (Jay Benesch) Date: Thu, 1 May 2025 10:56:37 -0400 Subject: [PEPPo] interesting solenoid article In-Reply-To: References: Message-ID: There are lots of arxiv posts on Halbach arrays with variable field strength. Radiation damage is an issue which is why Ryan has an LDRD with many samples in the tunnel with attached dosimeters. https://scholar.google.com/scholar?hl=en&as_sdt=0%2C47&q=halbach+array&oq=Halbach yields 22,800 results. -------------- next part -------------- A non-text attachment was scrubbed... Name: perm_mag_quad_var_1706.04355.pdf Type: application/pdf Size: 1296357 bytes Desc: not available URL: From rarimmer at jlab.org Thu May 1 11:29:47 2025 From: rarimmer at jlab.org (Robert Rimmer) Date: Thu, 1 May 2025 15:29:47 +0000 Subject: [PEPPo] interesting solenoid article In-Reply-To: References:

Message-ID: thanks Jay. Any papers posted on variable PM solenoids? I expect the radiation conditions in the positron target are much more severe than for the 22 GeV FFA. Bob. ________________________________ From: PEPPo on behalf of Jay Benesch via PEPPo Sent: Thursday, May 1, 2025 10:56 AM To: peppo at jlab.org Subject: Re: [PEPPo] interesting solenoid article There are lots of arxiv posts on Halbach arrays with variable field strength. Radiation damage is an issue which is why Ryan has an LDRD with many samples in the tunnel with attached dosimeters. https://scholar.google.com/scholar?hl=en&as_sdt=0%2C47&q=halbach+array&oq=Halbach yields 22,800 results. -------------- next part -------------- An HTML attachment was scrubbed... URL: From ziemann at jlab.org Thu May 1 11:40:52 2025 From: ziemann at jlab.org (Volker Ziemann) Date: Thu, 1 May 2025 11:40:52 -0400 Subject: [PEPPo] interesting solenoid article In-Reply-To: References:

Message-ID: Hi Bob, for what it's worth. I wrote a paper about permanent magnets, some of them ar variable. In there is a solenoid as well, though not variable. I need to revisit the paper to see whether the solenoid can be made adjustable as well. https://doi.org/10.3390/instruments5040036 Cheers, Volker On 5/1/25 11:29, Robert Rimmer via PEPPo wrote: > thanks Jay. Any papers posted on variable PM solenoids? I expect the radiation conditions in the positron target are much more severe than for the 22 GeV FFA. > Bob. > > ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ > *From:* PEPPo on behalf of Jay Benesch via PEPPo > *Sent:* Thursday, May 1, 2025 10:56 AM > *To:* peppo at jlab.org > *Subject:* Re: [PEPPo] interesting solenoid article > There are lots of arxiv posts on Halbach arrays with variable field > strength.? Radiation damage is an issue which is why Ryan has an LDRD > with many samples in the tunnel with attached dosimeters. > > https://scholar.google.com/scholar?hl=en&as_sdt=0%2C47&q=halbach+array&oq=Halbach > yields 22,800 results. > > _______________________________________________ > PEPPo mailing list > PEPPo at jlab.org > https://mailman.jlab.org/mailman/listinfo/peppo -- Volker Ziemann, Director for Accelerator Education Jefferson Lab professor at Old Dominion University Jefferson Laboratory, 12000 Jefferson Avenue, Newport News, VA 23606, USA ziemann at jlab.org, +1 757 269-7845, https://cern.ch/ziemann My books: https://cern.ch/ziemann/mybooks From benesch at jlab.org Thu May 1 11:46:12 2025 From: benesch at jlab.org (Jay Benesch) Date: Thu, 1 May 2025 11:46:12 -0400 Subject: [PEPPo] interesting solenoid article In-Reply-To: References:

Message-ID: <7d3eedc4-8ef7-44a0-94d7-1890910cc6f6@jlab.org> Volker's article via arxiv https://arxiv.org/abs/2106.14676 Strap-on magnets: a framework for rapid prototyping of magnets and beam lines Volker Ziemann We describe a framework to assemble permanent-magnet cubes in 3D-printed frames to construct dipole, quadrupole, and solenoid magnets, whose field, in the absence of iron, can be calculated analytically in three spatial dimensions. Rotating closely spaced dipoles and quadrupoles in opposite directions allows us to adjust the integrated strength of a multipole. Contributions of unwanted harmonics are calculated and found to be moderate. We then combine multiple magnets to construct beam-line modules: chicane, triplet cell, and solenoid focusing system. https://arxiv.org/abs/2207.09911 Magnetic Field of a Permanent Magnet David Shulman For magnetic field calculations, cylindrical permanent magnets are often approximated as ideal, azimuthally symmetric solenoids. Despite the frequent usage of this approximation, research papers demonstrating the validity and limitations of this approach are scarcely available. In this paper, the experimentally derived magnetic field of a cylindrical permanent magnet is compared with the analytically calculated magnetic field of an ideal solenoid. An experimental setup for measuring the magnetic field distribution is demonstrated and employed for gathering the data. The proposed setup allows to measure the distributions of the axial and radial components of the magnetic field surrounding the magnet. The experimental data is in a very good agreement with the theoretical predictions, confirming the validity of using the model of an ideal solenoid for predicting a magnetic field distribution of a permanent magnet. https://arxiv.org/abs/2305.17227 Practical Concepts for Design, Construction and Application of Halbach Magnets in Magnetic Resonance Peter Bl?mler, Helmut Soltner This review is a compilation of relevant concepts in designing Halbach multipoles for magnetic resonance applications. The main focus is on providing practical guidelines to plan, design and build such magnets. Therefore, analytical equations are presented for estimating the magnetic field from ideal to realistic systems. Various strategies of homogenizing magnetic fields are discussed together with concepts of opening such magnets without force, or combining them for variable fields. Temperature compensation and other practical aspects are also reviewed. For magnetic resonance two polarities (di- and quadrupole) are of main interest, but higher polarities are also included. Comments: 39 pages, 17 Figures From ushakov at jlab.org Tue May 6 10:22:05 2025 From: ushakov at jlab.org (Andriy Ushakov) Date: Tue, 6 May 2025 14:22:05 +0000 Subject: [PEPPo] Ce+BAF meeting on Wednesday, May 7 @ 11am EDT Message-ID: Dear e+ Colleagues, A quick reminder, we'll have the Ce+BAF meeting tomorrow at 11am EDT in TL-1227 and Zoom. Agenda * Andriy - Simulations of e+ injector with 250 MeV drive e- beam * Victor - Update on polarized processes in Geant4 Meeting page: 2025-05-07-Ce+BAF Zoom link: https://jlab-org.zoomgov.com/j/1607642988?pwd=K2VMVlkwLzFwR0l0VjNWMFUvSGtrUT09 Best regards, Andriy -------------- next part -------------- An HTML attachment was scrubbed... URL: