Ne Production at SARAF-I
Yonatan Mishnayot a,b, ∗ , Hitesh Rahangdale b , Ben Ohayon b,c , Sergey Vaintraub a , Tsviki Hirsh a , Leo Weismann a , AmichayPerry a , Asher Shor a , Arik Kreisel a , Shadi Ya’akobi a , Einat Buznach a , Guy Ron b a Soreq Nuclear Research Center, Yavne, 8180000 b The Racah Institute of Physics, The Hebrew University of Jerusalem, Givat Ram, Jerusalem, 9190401 c Institute for Particle Physics and Astrophysics, ETH Z¨urich, CH-8093 Z¨urich, Switzerland
In this article, we present a measurement of ﬂow rate, yield and e ﬀ usion time of a Ne production and transport system. Weused an accelerator-driven Li(d,n) neutron source to produce neutrons up to 20 MeV. The radioactive atoms were produced by a Na(n,p) reaction at a NaCl target. Later, the atoms were di ﬀ used out from the NaCl crystals and e ﬀ used from the productionchamber via a 10 m hose to a measurement cell and their decay products were detected using high purity germanium (HPGe) andplastic scintillator detectors. The resulting ﬂow rate was 6 . ± . · atoms / sec and the total yield was 3 . ± . · − atoms / deuteron . Wesummarize our methods and estimates of e ﬃ ciencies, rates of production and e ﬀ usion. Keywords: Ne, Magneto-Optical Trap, Precise Measurements
Most of the reactors that currently produce radioisotopes areexpected to come o ﬄ ine in the next few years . This makesradioisotope production at accelerator facilities, which are rela-tively cost-e ﬀ ective and easy to operate, a growing ﬁeld withapplications in nuclear medicine [2, 3], industry  and ba-sic science . In basic science, one such application is thesearch for Beyond Standard Model (BSM) physics in the weakinteraction, through precision measurements of decay parame-ters such as the beta-neutrino angular correlation coe ﬃ cient .This observable is predominantly measured today using ion oratom traps [7, 8, 9].In 2018, we began operating the trapping laboratory atthe Soreq Applied Research Accelerator Facility (SARAF)[10, 11]. Two dedicated trap systems were commissionedto measure β decay parameters: an Electrostatic Ion BeamTrap (EIBT) for He [12, 13], and a Magneto-Optical Trap(MOT) for neon isotopes [14, 15]. Since both systems involveshort-lived isotopes ( < ﬃ cient due tothe need to excite them to a meta-stable state [16, 17]. To ob-tain enough statistics from roughly 10 detected events [18, 9]within a reasonable beam time, one needs to produce theseatoms in ample quantities > atoms / sec . Only high-current ac-celerators can produce enough atoms to feed the trap.The following article will present the ﬁrst application of theSARAF-I accelerator for mass production of radioisotopes us-ing fast neutrons. We chose to focus on Ne, as only neon ∗ Corresponding author
Email address: [email protected] ( YonatanMishnayot ) isotopes will be trapped in the MOT as part of the trapping pro-gram for testing the SM, and Ne is the longest-lived and theeasiest to produce.The SARAF-I accelerator is designed to provide proton anddeuteron beam currents of up to 2 mA. SARAF can also serveas an intense neutron source using its Liquid Lithium Target(LiLiT) [19, 20]. A deuteron beam of 5 MeV produces neutronsof up to 20 MeV via the Li(d,n) reaction. At a full deuteronbeam, the production rate of Ne atoms is expected to be higherthan 10 atoms / sec .BeO and NaCl targets were designed and built for pro-duction of radioisotopes by neutron-induced nuclear reactions: Be(n, α ) He and Na(n,p) Ne, respectively. The half-lives ofthe radioisotopes are 806.89 ms  and 37.148 sec , re-spectively. The BeO target was made of porous lattice, whilethe NaCl target was made of powder, allowing better di ﬀ usion.In addition, both targets were heated to improve the di ﬀ usionfrom the crystal lattice. As both helium and neon are noblegases, they may be e ﬀ used through a vacuum hose. We choseto design a simple vacuum transport system rather than usingother methods that employ complex separation methods .The current experiment follows our group’s previous work atthe Weizmann Institute . The current experiment main goalwas to design an e ﬃ cient Ne production and transport appa-ratus. A prototype system, composed of a Na target, 10 mhose and a measurement cell, was constructed for this purpose.The target was irradiated with fast neutrons to produce Neatoms. The Ne atoms di ﬀ used outside the crystal lattice ande ﬀ used to the measurement cell. An array of β and γ detectorswas placed around the measurement cell and used to measurethe decays, identify contamination and estimate the quantity of Ne atoms produced and e ﬀ used. We describe the system inthe second section, and discuss the experimental results in the Preprint submitted to Nuclear Instruments and Methods in Physics Research Section A June 2, 2020 a r X i v : . [ nu c l - e x ] M a y hird and fourth sections.
The three main methods for Ne production are: • Deuteron-induced reactions such as Ne(d,p) at 2.6 MeV and Na(d,2p) at 22 MeV . • Thermal neutron-induced reaction Ne(n, γ ) on enrichedneon gas [26, 27]. • Fast neutron-induced reaction Na(n,p) on di ﬀ erentsodium compounds [28, 29, 30].Both deuteron-induced reactions and thermal neutron-inducedreactions were eliminated for the following reasons: A Negas target involve e ﬀ usion of stable neon gas throughout thesystem, e ﬀ ectively increasing the gas load in trap and reducingtrap lifetime; Deuteron-induced reactions complicate the targetdesign, which usually required a cooled target window. In ad-dition, the Na(d,2p) reaction at 22 MeV is above SARAF-Ibeam capabilities. In order to avoid e ﬀ usion of stable neon gasin the system, we chose the fast neutron reaction Na(n,p) withthreshold of 4 MeV . Since SARAF maximal deuteron en-ergy is 5.6 MeV, resulting in neutrons up to 20 MeV at neutronsource [32, 33], the choice of Na(n,p) reaction is optimal forSARAF. In addition, using Na(n,p) reaction simpliﬁes the tar-get design, avoiding the need for a special target window. NaClwas chosen as a target material due to its stability, ease of useand safety.The LiF Thick Target (LiFTiT)  was connected to theend of the SARAF beamline. The LiFTiT was made of 300 µ mthick LiF crystals glued to a water-cooled copper ﬂange. Thesurface of the crystals was painted with a thin layer of carbonpaint to avoid build up of the beam charge. The ﬂange was con-nected to the ﬁnal section of the beam line via a 20 cm pipe andTeﬂon sealing, allowing direct collection of beam charge fromthe electrically insulated ﬂange. The long connected pipe al-lowed e ﬃ cient collection of secondary electrons. A pair of per-manent magnets were set near the target ﬂange for secondarysuppression of electrons, and the accelerator tune was per-formed with the Rutherford backscattering monitor . Theﬁnal diagnostic station used for beam tuning was placed half ameter upstream from the LiF target. The beam duty cycle was1.4% and peak beam value was 250 µ A, corresponding to anaverage beam current of 3.4 µ A. A neutron dosimeter monitorwas placed 3 m from the LiFTiT to monitor neutron dose rateand the stability of the LiFTiT. As the LiF crystals could notsustain signiﬁcantly higher current, they were eventually burntout towards the end of the experiment.The target consisted of 1.4 kg of a ground table salt (NaCl)that was sifted to a crystal size smaller than 40 µ m. To verifythe crystal size, several samples of the sifted salt were mea-sured using scanning electron microscopy (SEM) (ﬁg. 1). TheSEM scans were analyzed using MIPAR software , whichshowed that the crystal size is exponentially distributed, withthe average being 10 µ m. The salt was stored in a produc- Figure 1: SEM scan of a salt sample, used to estimate the crystal’s size. tion chamber made of stainless steel half nipple (4” diame-ter, 32.5 cm height), wrapped in heating tape, glass wool andhigh-temperature aluminum tape. The production chamber wasplaced in front of the LiFTiT, and connected to a hose 10 min length and 3” in diameter, via a 4” gate valve that separatedthe production chamber from the hose. This separation enabledus to measure the e ﬀ usion time in the experiment. Prior to ex-periment, the production chamber was heated up to 380 °C toremove water vapors. During the experiment, the productionchamber was heated to an average temperature of 360 ± ﬀ usion of Ne atoms out of the salt crystals.The hose end was coupled to a 520 l / s turbo-molecular pump,whose outlet was connected to a 6 cm diameter (3.8 cm height)measurement cell via a 1” valve. Another 1” valve was con-nected the other side of the measurement cell to a roughingpump, which was pumped out to an exhaust line. Both valves– in the measurement cell inlet and outlet(valves 2 and 3 in ﬁg.2) – were used to control the ﬂow into the measurement celland the accumulation of Ne atoms in the cell. Fig. 2 shows aschematic view of the experimental system. S e r v i ce C o rr i do r A cce l e r a t o r C o rr i do r n - b e a m f r o m A cc l . c m w i de c on c r e t e w a ll V a l ve NaCl V a l ve Turbo
MeasurementCell T o R ough Text . c m d i a m e t e r m ho se Figure 2:
A sketch of the experimental system. The measurement cellsetup is shown in detail in ﬁg. 3.
The measurement cell iteslf had a 2 mm stainless steel win-2ow in front and a 25 µ m Mylar window in back. A p-typeHPGe (Ortec GEM40-83) detector was placed in front of thestainless steel window to measure γ rays. Two plastic scintil-lators were placed in front of the Mylar window as a ∆ E − E telescope. The telescope was made of a thin, square scintillator(0.5 mm thickness, 5 cm side length) and a thick, cylindricalscintillator (2.5 cm thickness, 8.8 cm diameter). Any particlethat left a signal in both scintillators was tagged as β particleand its energy measured by the thick scintillator. Fig. 3 showsschematically the measurement cell and detectors. Figure 3:
A sketch of the measurement system and the detectors:Leftmost—HPGe, with the measurement cell to its right. Rightmost—the thick scintillator, with the thin detector to its left.
3. Flow and Yield
In this section, we discuss the experimental results obtainedin long measurements ( ∼
30 min). During the measurements weleft both valves 1 and 2 (presented in ﬁg. 2) open, while valve 3was closed and opened to empty the measurement cell when itspressure increased to 2-3 Torr (1–3 times during a single mea-surement). In the ﬁrst subsection, we discuss the yield and ﬂow-rate evaluation of the long measurements data. In the secondand third subsections, we discuss two additional results foundin the long measurement data: the di ﬀ usion of Ne atoms outof the salt crystals and the detection of other radioisotopes inthe measurement cell.
In order to calculate the ﬂow rate into the measurement cell,we used the major γ peak of Ne at 440 keV obtained by HPGe(ﬁg. 4). We took a histogram of the events’ time stamps andﬁtted it to the expected ﬂow, described by: λ N = K + C · exp ( − λ t ) (1)where K is ﬂow rate at longer times – after several minutes, λ N is number of decays in the measurement cell, C is constant and λ = ln / t / is the decay time constant. We considered severalfactors during the evaluation of decays in the measurement cell:the HPGe e ﬃ ciency; the branching ratio (BR) of Ne (see ﬁg.6); and losses of γ rays in the stainless steel window. In ad-dition, we had to correct the volume of the measurement cell,as the atoms were spread throughout the volume between the pump outlet and the last valve, while we measured only the de-cays in front of the window. We found the resulting ﬂow rate tobe 6 . ± . · atoms / sec . Once we had calculated the ﬂow rateand the beam current, we evaluated the yield easily by dividingthe ﬂow rate by the number of deuterons in the beam. We foundthat the total yield was 3 . ± . · − atoms / deuteron . ﬀ usion In order to evaluate the di ﬀ usion out of the salt crystals, wehad to calculate the e ﬀ usion e ﬃ ciency throughout the system,making it easy to exclude the e ﬀ usion and focus only on thedi ﬀ usion process. To calculate the e ﬀ usion e ﬃ ciency, we simu-lated it in Molﬂow, following the comparison in the next section4. We deﬁned the e ﬀ usion e ﬃ ciency as the number of atomsthat passed the turbo pump, divided by the number atoms emit-ted from the target. In addition, we set the target to emit atomscontinuously. Thereafter, we used Molﬂow to simulate the ef-fusion e ﬃ ciency of radioactive Ne with a half life time of37.15 sec and found the e ﬀ usion e ﬃ ciency to be 91%. Con-sidering the Ne ﬂow rate into the measurement cell (as calcu-lated in section 3.1) and the e ﬀ usion e ﬃ ciency, we calculatedthat the Ne ﬂow rate at the production chamber outlet was7 . ± . · atoms / sec .After obtaining the Ne ﬂow rate in the production chamberoutlet, we had to ﬁnd the Ne production rate in the salt target.Due to the high neutron ﬂux on the salt target, we could not di-rectly measure the Ne production rate in the target. Therefore,we simulated it using GEANT4 [37, 38, 39] as follows: First,we inserted the neutron emission spectrum of 5 MeV deuteronbeam on LiFTiT [32, 33] into GEANT4. Then we simulatedthe Na(n,p) Ne reaction in the salt target using GEANT4.Normalizing the results to the beam current, we found that theproduction rate was 1 . ± . · atoms / sec . Having both Neproduction rate and ﬂow rate at the production chamber outlet,we divided the ﬂow rate by the production rate to get a dif-fusion e ﬃ ciency of 4 . ± . · − , equivalent to a di ﬀ usiontime of 166 ± ﬀ usion time and the averagedtemperature, we calculated the average crystal size as a sanitycheck. Our calculation is based on the calculation in . As-suming cubic crystals, we calculated the average crystal size tobe 47 ± µ m. Although that result is not consistent with theaverage crystal size obtained by SEM (in the Methods section2), it is very close to the upper limit obtained by the sieve of40 µ m. Therefore, given the uncertainties of temperature anddi ﬀ usion time, the sanity check justiﬁes our results. Throughout the experiment, we were surprised to ﬁnd ra-dioisotopes other than Ne in the measurement cell. Gener-ally, due to the inertness of noble elements, we would expecttheir atoms to di ﬀ use as mono-atomic molecules out of the saltcrystals and to e ﬀ use throughout the system to the measure-ment cell. In contrast, we expected atoms of other elements tobe trapped in the crystal lattice or be absorbed by the systemwalls.3 igure 4: Zoom in on a HPGe spectrum, focusing the 440 keV Nepeak. The spectrum was compared to the normalized accelerator’sbackground. The background was taken when the accelerator was on,but valve no. 1 in ﬁg. 2 was closed
During the experiment we detected clear traces of other ele-ments, particularly S. Since the contribution of S was negli-gible ( ∼ Ne e ﬀ usion.In the HPGe spectrum, we found the 3103 keV S γ peak andits escape peak at 2592 keV (in ﬁg. 5). The S is produced inthe Cl(n,p) S reaction, with a threshold of 11 MeV , andits half life time is 5.05 min. We assume that due to its highvapor pressure at high temperatures, 10 kPa at 591 K , thesulfur atoms or molecules di ﬀ used out of the salt crystals andreached the measurement cell.Another possible contamination is F, produced by the Na(n, α ) F reaction with threshold of 6 MeV . Basedon , we are almost certain that F was produced in the salttarget. However, we wanted to conﬁrm or reject the existence of F in the measurement cell. Since the strongest γ peak energyof F is 1633 keV, it interferes with the 1636 keV Ne peak.On the other hand, we can use the 1636 keV peak to test for F in the measurement cell. We calculated the resulting ratioof Ne 1636 and 440 keV peaks (the Ne peaks in ﬁgs. 4 and5) as 2 . ± . Na, no F wasproduced in targets made of Ne. Therefore, we compared ourcalculated ratio to the previous results of Ne branching ratiomeasurements conducted using Ne target. The previous re-sults were 2 . ± .
06%  and 3 . ± .
12% , while ourresult was 2 . ± . F in themeasurement cell. We assume that due to its high reactivity, F atoms were bound to Na atoms in the crystal lattice.
4. System Design
In the future, we plan to produce and convey several radioiso-topes to our trapping systems, especially noble gases. Since no-ble gases are inert, we would like to transport the atoms via ef-fusion through vacuum pipes, and simulate the e ﬀ usion through Figure 5:
Zoom in on a HPGe spectrum, focusing on the 1636 and 2076keV Ne peaks and the S peaks. The spectrum is compared to a nor-malized accelerator background. The unlabeled peaks are activationpeaks of the HPGe. The background was taken when the acceleratorwas on, but valve no. 1 in ﬁg. 2 was closed the vacuum transport system as part of its design process. Wetherefore chose Molﬂow , a dedicated simulation tool forvacuum systems, to simulate our system. In order to validateour simulation results, we used short measurements with an out-put comparable to our simulation results. In the ﬁrst subsection,we discuss the measurements independent of the simulations,while in the second subsection we describe the simulations anddiscuss their comparison to the measurements. ﬀ usion Since the number of Ne atoms is negligible compared toother gases in the system, we chose to measure its decays in themeasurement cell. The measurement included several cycles,each lasting 150 sec, in which all cycles had the same e ﬀ usionproﬁle to maintain consistency. We started the cycles when thegate valve on top of the production chamber (valve 1 in systemscheme, ﬁg. 2) was closed for 30 seconds. After 30 seconds, weopened the gate valve on top of the production chamber for 5seconds and then closed it again. After 150 seconds, we openedthe valve to the rough pump and exhaust line (valve 3 in systemscheme, ﬁg. 2) to empty the cell. Valve 2 in ﬁg. 2 was left openduring the whole measurement.We used the ∆ E − E telescope to tag the emitted β particlesthroughout the cycle, focusing on time proﬁle rather than en-ergy and absolute yield. The measurement results are shown inthe blue dotted curve shown in the bottom right subﬁgure of thesimulation and experiment comparison in ﬁg. 7. As described at the beginning of this section, we usedMolﬂow to simulate the e ﬀ usion throughout the system. Moreprecisely, we used Molﬂow to simulate the e ﬀ usion of Neatoms from the production chamber outlet—where the atomswere created in simulation—to the measurement cell inlet,4 / + / + / + / + / + Q β − = . . s . . . . f s f s . psstable . . M ( + E ) . . M + E . . E ( + M ) . . M + E . M + E . . . . . . Ne Na Figure 6: The decay scheme of Ne. where the atoms were destroyed in simulation and where wemeasured the decays.While using Molﬂow, our main challenge was the e ﬀ usion ofparticles through vacuum pumps. In Molﬂow, vacuum pumpsare sinks; i.e., any particle that goes in is destroyed. However,we were interested in particles that passed through the vacuumpumps. Rather than using pump elements in the simulation,we modeled the pump by inserting two planes into the pumpbody. The ﬁrst plane was partially opaque toward the particlesource at the production chamber outlet, while the second, 1 cmdownstream, was fully opaque toward the particle sink at themeasurement cell inlet. We calculated the ﬁrst plane opacity tobe 90%.We changed both pipe length and plane opacity values insteps of 25 cm and 2.5% respectively (except the highest opac-ity value, where we used 99% instead of 100%, which wouldmean no e ﬀ usion), to validate the assignment of the measuredpipe length—10 m with a calculated plane opacity of 90% inthe simulation. In addition to the measured pipe length andcalculated plane opacity, we simulated 4 points below and 4points above for both parameters to get 81 simulations. Thenwe modiﬁed the simulation results and compared them to theexperimental data. The simulation process and its modiﬁcationto compare it to experimental data is described below:1. We started with a surface source of Ne atoms on top ofthe salt target, and the source emitted atoms for 5 sec (ﬁg.7, upper left). This source is equivalent to opening the gatevalve on top of the production chamber for 5 sec.2. We simulated the e ﬀ usion of Ne atoms to the measure-ment cell inlet as a function of time using Molﬂow (ﬁg. 7,bottom left).3. We accumulated the e ﬀ used atoms to ﬁnd the number ofatoms in the measurement cell as a function of time (ﬁg. 7, top right).4. We applied a radioactive decay with t / = .
15 sec to themodiﬁed simulation results. Then we normalized the sim-ulation results with radioactive decay to the experimentaldata. (ﬁg. 7, bottom right).
The simulation process and comparison to experimental data(left to right). The ﬁrst three ﬁgures (top row and bottom left) show thesimulation process as described in the Molﬂow simulations subsection4.2, and the bottom right ﬁgure shows the comparison to experimentaldata after applying decay and normalizing, with the di ﬀ erent regionsseparated by a vertical black line. Since the opening time of the gate valve on top of the pro-duction chamber was not ﬁxed, we did not have a well-deﬁnedexperimental starting point to compare to our Molﬂow simu-lations. Instead, we shifted the simulation results relative tothe determined opening time in steps of 0.5 seconds up to 2.5seconds. Then we compared the shifted simulation results tothe experimental data. As clearly seen in the bottom right sub-ﬁgure of ﬁg 7, following the vertical black line, we can dividethe time scale into two separate regions dominated by di ﬀ erentprocesses. The e ﬀ usion dominates the ﬁrst, up to ∼
20 seconds,while the decay dominates the second, from 20 seconds to theend of measurement. Since we focused on the e ﬀ usion timerather than the decay, we used only the ﬁrst 20 seconds to cal-culate the χ value of the simulations at each shift (6 sets of81 values, 486 χ values in total). We found the minimal χ value of 2.86 at shift of 1 sec, pipe length of 1025 cm and planeopacity of 97.5%. We can see that the deviation of the ’cor-rect’ simulated pipe length from the measured value is smalland acceptable. However, the deviation of the ’correct’ simu-lated plane opacity from the calculated value is larger. Sincethe calculation of the plain opacity involves several parameters,we assume that deviation in some of the inputs increased itsdeviation. The χ map at shift of 1 is shown in ﬁg. 8. As mentioned previously, we plan to to produce and transportother radioisotopes to our trapping system. The next radioiso-tope to be trapped in our lab is He. In contrast to Ne, the He5 igure 8: A χ map at a shift of 1 sec, the minimal χ obtained for alength of 1025 and opacity of 97.5%. half life is much shorter – 0.807 ms. Thus, we would like toestimate the yield of our transport system for a future use with He. Following the comparison between our simulations to ex-perimental results, we can reliably estimate the transport timesand yield of our system for He atoms. Table 1 shows the es-timated time took for a given fraction of the atoms to enter themeasurement cell. the table includes both Ne and He, theestimated uncertainties are 0.5 and 0.1 seconds respectively.
Isotope 1% 5% 10% 25% 50% 75% 90% Ne 1.5 2.5 3.0 4.5 6.5 9.5 13.5 He 1.0 1.6 2.2 3.4 5.0 6.6 8.6
Table 1: Comparison of transport times in seconds for Ne and He at di ﬀ erentpercentages, the uncertainties are 0.5 and 0.1 seconds respectively. Another result that can be extracted using the simulation isthe yield of our transport system for He. Contrary to the timedependent measurements and simulations discussed in this sec-tion, we simulated the yield of a target emitting atoms continu-ously (in the Di ﬀ usion subsection 3.2). We divided the numberof atoms that passed the turbo pump by the number of atomsemitted from the target. We found the e ﬀ usion e ﬃ ciency of He to be 24% compared to 91% of Ne.
In this article, we presented the methods we used to calcu-late the ﬂow rate, yield and e ﬀ usion time of Ne in our proto-type production and transport system. We validated our use ofMolﬂow to simulate the e ﬀ usion in vacuum systems by compar-ing it to experimental data of dynamic measurements. There-after, we ﬁtted of Ne γ peaks at 440 and 1636 keV and usedMolﬂow and GEANT4 simulations to extract the ﬂow rate andyield. Following the ﬁttings and simulations, we found the re-sulting ﬂow rate to be 6 . ± . · atoms / sec and the total yield to be 3 . ± . · − atoms / deuteron . Additionally, we calculated thedi ﬀ usion time out of salt crystals and found it to be 167 ± ﬀ usion dominates the sys-tem yield while the e ﬀ usion e ﬀ ects are secondary. Therefore,changing the transport line length by a meter or two will notchange the ﬂow rate signiﬁcantly. Whereas, reducing the dif-fusion time will improve the yield dramatically. A comparisonperformed between H and Ne using Molﬂow simulations,also showed that the e ﬀ usion contribution to the system yield issecondary, even in the case of short-lived isotopes.To meet the requirements of the MOT, we need to redesignthe system to increase its ﬂux production. Following the con-clusions, we need to consider to improve the di ﬀ usion by in-creasing the mass and the temperature [46, 47] of the salt in thetarget.We have already designed a new production chamber follow-ing these factors. The new production chamber includes threearms, each of which contains 1.6 kg of salt and can be heatedup to 600 ◦ C. In preliminary measurements of the new produc-tion chamber, taken during the last year, scaled following themethods described in this article to SARAF-II, and given higherbeam energies with current of 1 mA at 100% duty cycle - pro-ducing neutrons at averaged energy of 10-15 MeV - we esti-mate the Ne ﬂux to be > atoms / sec . Therefore, we expect thenew production chamber to fulﬁll the MOT requirements, feedthe MOT with su ﬃ cient ﬂux and allow experiments to be com-pleted in a reasonable time.
The work presented here is supported by grants from thePazy Foundation (Israel), and the Israel Science Foundation(grants no. 139 /
15 and 1446 / References  V. N. Starovoitova, L. Tchelidze, D. P. Wells, Production of medicalradioisotopes with linear accelerators, Applied Radiation and Isotopes 85(2014) 39 – 44. I. of Medicine, Isotopes for Medicine and the Life Sciences, The NationalAcademies Press, Washington, DC, 1995. B. Zhuikov, Production of medical radionuclides in russia: Status andfuturea review, Applied Radiation and Isotopes 84 (2014) 48 – 56. R. W. Hamm, M. E. Hamm, Industrial Accelerators and Their Applica-tions, WORLD SCIENTIFIC, 2012. E. P. Abel, M. Avilov, V. Ayres, E. Birnbaum, G. Bollen, G. Bonito,T. Bredeweg, H. Clause, A. Couture, J. DeVore, M. Dietrich, P. Elli-son, J. Engle, R. Ferrieri, J. Fitzsimmons, M. Friedman, D. Georgobiani, . Graves, J. Greene, S. Lapi, C. S. Loveless, T. Mastren, C. Martinez-Gomez, S. McGuinness, W. Mittig, D. Morrissey, G. Peaslee, F. Pelle-moine, J. D. Robertson, N. Scielzo, M. Scott, G. Severin, D. Shaughnessy,J. Shusterman, J. Singh, M. Stoyer, L. Sutherlin, A. Visser, J. Wilkinson,Isotope harvesting at FRIB: additional opportunities for scientiﬁc discov-ery, Journal of Physics G: Nuclear and Particle Physics 46 (2019) 100501. M. Gonzlez-Alonso, O. Naviliat-Cuncic, N. Severijns, New physicssearches in nuclear and neutron decay, Progress in Particle and NuclearPhysics 104 (2019) 165 – 223. P. Shidling, V. Kolhinen, B. Schroeder, N. Morgan, A. Ozmetin, D. Mel-conian, Tamutrap facility: Penning trap facility for weak interaction stud-ies, Hyperﬁne Interactions 240 (2019). P. OMalley, M. Brodeur, D. Burdette, J. Klimes, A. Valverde, J. Clark,G. Savard, R. Ringle, V. Varentsov, Testing the weak interaction using st.benedict at the university of notre dame, Nuclear Instruments and Meth-ods in Physics Research Section B: Beam Interactions with Materials andAtoms 463 (2020) 488 – 490. B. Ohayon, H. Rahangdale, E. Parnes, G. Perelman, O. Heber, G. Ron,Decay microscope for trapped neon isotopes, Phys. Rev. C 101 (2020)035501. B. Ohayon, J. Chocron, T. Hirsh, A. Glick-Magid, Y. Mishnayot,I. Mukul, H. Rahangdale, S. Vaintraub, O. Heber, D. Gazit, G. Ron, Weakinteraction studies at saraf, Hyperﬁne Interactions 239 (2018). Mardor, Israel, Aviv, Ofer, Avrigeanu, Marilena, Berkovits, Dan, Da-han, Adi, Dickel, Timo, Eliyahu, Ilan, Gai, Moshe, Gavish-Segev, In-bal, Halfon, Shlomi, Hass, Michael, Hirsh, Tsviki, Kaiser, Boaz, Kijel,Daniel, Kreisel, Arik, Mishnayot, Yonatan, Mukul, Ish, Ohayon, Ben,Paul, Michael, Perry, Amichay, Rahangdale, Hitesh, Rodnizki, Jacob,Ron, Guy, Sasson-Zukran, Revital, Shor, Asher, Silverman, Ido, Tessler,Moshe, Vaintraub, Sergey, Weissman, Leo, The soreq applied researchaccelerator facility (saraf): Overview, research programs and future plans,Eur. Phys. J. A 54 (2018) 91. M. Hass, S. Vaintraub, O. Aviv, K. Blaum, O. Heber, I. Mardor, M. Rap-paport, A. Wolf, D. Zajfman, A novel method for fundamental interactionstudies with an electrostatic ion beam trap, in: Journal of Physics: Con-ference Series, volume 267, IOP Publishing, p. 012013. I. Mukul, M. Hass, O. Heber, T. Hirsh, Y. Mishnayot, M. Rappaport,G. Ron, Y. Shachar, S. Vaintraub, A 6he production facility and an elec-trostatic trap for measurement of the betaneutrino correlation, NuclearInstruments and Methods in Physics Research Section A: Accelerators,Spectrometers, Detectors and Associated Equipment 899 (2018) 16 – 21. B. Ohayon, G. Ron, Investigation of di ﬀ erent magnetic ﬁeld conﬁgura-tions using an electrical, modular zeeman slower, Review of ScientiﬁcInstruments 86 (2015) 103110. B. Ohayon, H. Rahangdale, J. Chocron, Y. Mishnayot, R. Koslo ﬀ ,O. Heber, G. Ron, Imaging recoil ions from optical collisions betweenultracold, metastable neon isotopes, Physical review letters 123 (2019)063401. M. Zinner, P. Spoden, T. Kraemer, G. Birkl, W. Ertmer, Precision mea-surement of the metastable P lifetime of neon, Phys. Rev. A 67 (2003)010501. B. Ohayon, E. Wåhlin, G. Ron, Characterization of a metastable neonbeam extracted from a commercial rf ion source, Journal of Instrumenta-tion 10 (2015) P03009. M. Gonz´alez-Alonso, O. Naviliat-Cuncic, Kinematic sensitivity to theﬁerz term of β -decay di ﬀ erential spectra, Phys. Rev. C 94 (2016) 035503. G. Feinberg, M. Paul, A. Arenshtam, D. Berkovits, D. Kijel, A. Nagler,I. Silverman, Lilit-a liquid-lithium target as an intense neutron sourcefor nuclear astrophysics at the soreq applied research accelerator facility,Nuclear Physics A 827 (2009) 590c–592c. I. Silverman, A. Arenshtam, D. Berkovits, I. Eliyahu, I. Gavish, A. Grin,S. Halfon, M. Hass, T. Hirsh, B. Kaizer, et al., Scientiﬁc opportunities atsaraf with a liquid lithium jet target neutron source, in: AIP conferenceproceedings, volume 1962, AIP Publishing, p. 020002. A. Knecht, et al., Precision measurement of the He-6 half-life and theweak axial current in nuclei, Phys. Rev. C 86 (2012) 035506. A. T. La ﬀ oley, C. E. Svensson, C. Andreoiu, G. C. Ball, P. C. Bender,H. Bidaman, V. Bildstein, B. Blank, D. S. Cross, G. Deng, A. D. Varela,M. R. Dunlop, R. Dunlop, A. B. Garnsworthy, P. E. Garrett, J. Giovinazzo,G. F. Grinyer, J. Grinyer, G. Hackman, B. Hadinia, D. S. Jamieson,B. Jigmeddorj, D. Kisliuk, K. G. Leach, J. R. Leslie, A. D. MacLean, D. Miller, B. Mills, M. Moukaddam, A. J. Radich, M. M. Rajabali, E. T.Rand, J. C. Thomas, J. Turko, C. Unsworth, P. Voss, High-precision half-life measurements for the superallowed fermi β + emitter Ne, Phys. Rev.C 92 (2015) 025502. T. Segal, The Production of Ne via the Na (n,p) Reaction, Master’sthesis, The Hebrew University of Jerusalem, Givat Ram, 2014. E. Pollard, W. W. Watson, Transmutation of the separated isotopes ofneon by deuterons, Physical Review 58 (1940) 12. J. R. Penning, F. H. Schmidt, Radioactive Decay of Ne , Phys. Rev. 105(1957) 647–651. R. Moreh, J. Balderman, Y. Gozez, Decay of 23ne, Nuclear Physics A107 (1968) 236 – 240. H. Lancman, A. JasiÅski, J. Kownacki, J. Ludziejewski, The decayscheme of ne23, Nuclear Physics 69 (1965) 384 – 400. T. Bjerge, Radioactive neon, Nature 139 (1937) 757. R. L. Burman, W. B. Herrmannsfeldt, J. S. Allen, T. H. Braid, Electron-neutrino angular correlation in the beta decay of neon-23, Phys. Rev. Lett.2 (1959) 9–11. B. Ridley, The electron-neutrino angular correlation in decay of ne23,Nuclear Physics 6 (1958) 34 – 49. C. F. Williamson, Absolute cross sections of the reactions na ( n , p )ne and na ( n , α )f , Phys. Rev. 122 (1961) 1877–1882. T. Y. Hirsh, Production of 8 Li and 6 He radioactive beams in high currentdeuteron accelerators, Ph.D. thesis, Weizmann Institute of Science, 2012. I. Mardor, D. Berkovits, The soreq applied research accelerator facility(saraf), Nuclear Physics News 25 (2015) 16–22. T. Hirsh, D. Berkovits, M. Hass, P. Jardin, A. Pichard, M. Rappaport,Y. Shachar, I. Silverman, Towards an intense radioactive 8li beam at sarafphase i, in: Journal of Physics: Conference Series, volume 337, IOPPublishing, p. 012010. L. Weissman, D. Berkovits, Y. Eisen, S. Halfon, I. Mardor, A. Perry,J. Rodnizki, First experience at saraf with proton beams using the ruther-ford scattering monitor, DIPAC 2009 - 9th European Workshop on BeamDiagnostics and Instrumentation for Particle Accelerators (2009). J. Sosa, D. Huber, B. Welk, H. Fraser, Mipar TM : 2d and 3d image analysissoftware designed by materials scientists, for all scientists, Microscopyand Microanalysis 23 (2017) 230–231. S. Agostinelli, J. Allison, K. Amako, J. Apostolakis, H. Araujo, P. Arce,M. Asai, D. Axen, S. Banerjee, G. Barrand, F. Behner, L. Bellagamba,J. Boudreau, L. Broglia, A. Brunengo, H. Burkhardt, S. Chauvie,J. Chuma, R. Chytracek, G. Cooperman, G. Cosmo, P. Degtyarenko,A. Dell’Acqua, G. Depaola, D. Dietrich, R. Enami, A. Feliciello, C. Fer-guson, H. Fesefeldt, G. Folger, F. Foppiano, A. Forti, S. Garelli, S. Gi-ani, R. Giannitrapani, D. Gibin, J. G. Cadenas], I. Gonzlez, G. G.Abril], G. Greeniaus, W. Greiner, V. Grichine, A. Grossheim, S. Guatelli,P. Gumplinger, R. Hamatsu, K. Hashimoto, H. Hasui, A. Heikki-nen, A. Howard, V. Ivanchenko, A. Johnson, F. Jones, J. Kallen-bach, N. Kanaya, M. Kawabata, Y. Kawabata, M. Kawaguti, S. Kelner,P. Kent, A. Kimura, T. Kodama, R. Kokoulin, M. Kossov, H. Kurashige,E. Lamanna, T. Lampn, V. Lara, V. Lefebure, F. Lei, M. Liendl, W. Lock-man, F. Longo, S. Magni, M. Maire, E. Medernach, K. Minamimoto,P. M. de Freitas], Y. Morita, K. Murakami, M. Nagamatu, R. Nar-tallo, P. Nieminen, T. Nishimura, K. Ohtsubo, M. Okamura, S. O’Neale,Y. Oohata, K. Paech, J. Perl, A. Pfei ﬀ er, M. Pia, F. Ranjard, A. Rybin,S. Sadilov, E. D. Salvo], G. Santin, T. Sasaki, N. Savvas, Y. Sawada,S. Scherer, S. Sei, V. Sirotenko, D. Smith, N. Starkov, H. Stoecker,J. Sulkimo, M. Takahata, S. Tanaka, E. Tcherniaev, E. S. Tehrani], M. Tro-peano, P. Truscott, H. Uno, L. Urban, P. Urban, M. Verderi, A. Walkden,W. Wander, H. Weber, J. Wellisch, T. Wenaus, D. Williams, D. Wright,T. Yamada, H. Yoshida, D. Zschiesche, Geant4a simulation toolkit, Nu-clear Instruments and Methods in Physics Research Section A: Accelera-tors, Spectrometers, Detectors and Associated Equipment 506 (2003) 250– 303. J. Allison, K. Amako, J. Apostolakis, H. Araujo, P. Arce Dubois, M. Asai,G. Barrand, R. Capra, S. Chauvie, R. Chytracek, G. A. P. Cirrone,G. Cooperman, G. Cosmo, G. Cuttone, G. G. Daquino, M. Donszel-mann, M. Dressel, G. Folger, F. Foppiano, J. Generowicz, V. Grichine,S. Guatelli, P. Gumplinger, A. Heikkinen, I. Hrivnacova, A. Howard,S. Incerti, V. Ivanchenko, T. Johnson, F. Jones, T. Koi, R. Kokoulin,M. Kossov, H. Kurashige, V. Lara, S. Larsson, F. Lei, O. Link, F. Longo,M. Maire, A. Mantero, B. Mascialino, I. McLaren, P. Mendez Lorenzo, . Minamimoto, K. Murakami, P. Nieminen, L. Pandola, S. Parlati,L. Peralta, J. Perl, A. Pfei ﬀ er, M. G. Pia, A. Ribon, P. Rodrigues,G. Russo, S. Sadilov, G. Santin, T. Sasaki, D. Smith, N. Starkov,S. Tanaka, E. Tcherniaev, B. Tome, A. Trindade, P. Truscott, L. Ur-ban, M. Verderi, A. Walkden, J. P. Wellisch, D. C. Williams, D. Wright,H. Yoshida, Geant4 developments and applications, IEEE Transactionson Nuclear Science 53 (2006) 270–278. J. Allison, K. Amako, J. Apostolakis, P. Arce, M. Asai, T. Aso, E. Bagli,A. Bagulya, S. Banerjee, G. Barrand, B. Beck, A. Bogdanov, D. Brandt,J. Brown, H. Burkhardt, P. Canal, D. Cano-Ott, S. Chauvie, K. Cho,G. Cirrone, G. Cooperman, M. Corts-Giraldo, G. Cosmo, G. Cuttone,G. Depaola, L. Desorgher, X. Dong, A. Dotti, V. Elvira, G. Folger,Z. Francis, A. Galoyan, L. Garnier, M. Gayer, K. Genser, V. Grichine,S. Guatelli, P. Guye, P. Gumplinger, A. Howard, I. HÅivnov, S. Hwang,S. Incerti, A. Ivanchenko, V. Ivanchenko, F. Jones, S. Jun, P. Kai-taniemi, N. Karakatsanis, M. Karamitros, M. Kelsey, A. Kimura, T. Koi,H. Kurashige, A. Lechner, S. Lee, F. Longo, M. Maire, D. Mancusi,A. Mantero, E. Mendoza, B. Morgan, K. Murakami, T. Nikitina, L. Pan-dola, P. Paprocki, J. Perl, I. Petrovi, M. Pia, W. Pokorski, J. Quesada,M. Raine, M. Reis, A. Ribon, A. R. Fira], F. Romano, G. Russo, G. Santin,T. Sasaki, D. Sawkey, J. Shin, I. Strakovsky, A. Taborda, S. Tanaka,B. Tom, T. Toshito, H. Tran, P. Truscott, L. Urban, V. Uzhinsky, J. Ver-beke, M. Verderi, B. Wendt, H. Wenzel, D. Wright, D. Wright, T. Ya-mashita, J. Yarba, H. Yoshida, Recent developments in geant4, NuclearInstruments and Methods in Physics Research Section A: Accelerators,Spectrometers, Detectors and Associated Equipment 835 (2016) 186 –225. R. V¨ansk¨a, R. Rieppo, Measurement of the average cross sections for(n, p) reactions on some light and medium mass nuclei in the 241 ambeneutron spectrum, The International Journal of Applied Radiation andIsotopes 30 (1979) 513 – 514. W. A. West, A. W. C. Menzies, The vapor pressures of sulphur between100 and 550 with related thermal data, The Journal of Physical Chemistry33 (1929) 1880–1892. H. Weigmann, G. F. Auchampaugh, P. W. Lisowski, M. S. Moore, G. L.Morgan, Neutron induced charged particle reactions on 23na, in:K. H. B¨ockho ﬀ (Ed.), Nuclear Data for Science and Technology, SpringerNetherlands, Dordrecht, 1983, pp. 814–817. H. J. Gerber, M. G. Mu˜noz, D. Maeder, Beta Decay of Ne , PhysicalReview 101 (1956) 774–775. D. E. Alburger, Decays of 21na, 23ne, 23mg, 24ne, and 31s, PhysicalReview C 9 (1974) 991–995. R. Kersevan, M. Ady, Recent developments of Monte-Carlo codesMolﬂow + and Synrad + , in: 10th International Particle Accelerator Con-ference, p. TUPMP037. H. Mehrer, Di ﬀ usion in Solids: Fundamentals, Methods, Materials,Di ﬀ usion-Controlled Processes, Springer Series in Solid-State Sciences,Springer, Berlin, Heidelberg, 2007. D. R. Askeland, P. P. Fulay, W. J. Wright, The Science and Engineeringof Materials, SI Edition, CL-Engineering, 6th edition, 2011.usion-Controlled Processes, Springer Series in Solid-State Sciences,Springer, Berlin, Heidelberg, 2007. D. R. Askeland, P. P. Fulay, W. J. Wright, The Science and Engineeringof Materials, SI Edition, CL-Engineering, 6th edition, 2011.