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In this paper we compare galactic electron spectra measured up to TeV energies by AMS2 and CALET and that measured by Voyager at the lowest energies down to 1 MeV with that calculated using a Monte Carlo diffusion model for electron propagation in the galaxy. The observations and calculations at both ends of the electron spectrum, differing by a factor ~10^6 in energy, can be matched to within a few percent with a minimal set of assumptions. This includes an electron spectrum which has an index increasing from ~2.1 at the lowest energies to 2.4 at ~1 TeV, along with a diffusion coefficient that remains essentially constant below ~1.5 GV above which it becomes P^0.45. The Monte Carlo calculations indicate that the lowest and highest energy electrons originate within a local region near the galactic plane of size, less than L where L is the thickness of the trapping region. The remarkable agreement to within a few percent between the calculations and measurements from 20 GeV up to ~1 TeV also indicates that there are no individual sources greater than 10-20 percent of the Monte Carlo calculated background that are contributing to the observed electron intensity in this energy range., Comment: 13 pages, 3 Figures

In this paper we report a study of the isotopic composition of Li, Be, B and N, Ne nuclei from a 5 year time period beyond the heliopause using the CRS instruments on Voyager. By comparing the isotopic ratios, 15N/14N and 22Ne/20Ne outside the heliosphere as measured at Voyager, and which are found to be significantly lower than those measured at the same energy inside the heliosphere, we have provided strong evidence that cosmic rays of this energy have lost as much as 200 MeV/nuc or more in the solar modulation process. This is in accordance with the so called force field description of this overall modulation by Gleeson and Axford. The measurements at Voyager confirm that the unusual 14N and 22Ne cosmic ray source abundances relative to solar abundances made earlier inside the heliosphere extend to the lower energies not accessible from near Earth measurements. The low energy Li, Be and B nuclei, which are believed to be purely secondary nuclei, are found to have a (previously unobservable) peak in the differential intensity spectrum at ~100 MeV/nuc. This is in agreement with propagation predictions. The intensities of these nuclei are ~10-20% higher than those predicted in a propagation model with a matter path length lambda = 9 g/cm2 at these low energies. The isotopic composition of Li, Be and B nuclei is also consistent with that expected from propagation through interstellar matter., Comment: 16 PAGES, 2 TABLES, 5 FIGURES

Studies on Voyager 1 using the CRS instrument have shown the presence of sub-MeV electrons in the interstellar medium beyond the heliopause. We believe that these electrons are the very low energy tail of the distribution of galactic GeV cosmic ray electrons produced in the galaxy. If so this observation places constraints on the origin and possible source distribution of these electrons in the galaxy. The intensities of these electrons as well as MeV protons and other higher energy electrons and nuclei have been followed outward from the Earth to beyond the heliopause during the 40 years of the Voyager mission. Among the other new features found in this study of the radial dependence of the electron intensity in the heliosphere are: 1. The heliosheath is a source of sub-MeV electrons as well as the already known anomalous cosmic rays of MeV and above, none of which appear to escape from the heliosphere because of an almost impenetrable heliopause at these lower energies; 2. Solar modulation effects are observed for these MeV electrons throughout the heliosphere. These modulation effects are particularly strong for electrons in the heliosheath and comprise over 90 percent of the observed intensity change of these electrons of 10-60 MeV between the Earth and the heliopause. Even for nuclei of 1 GV in rigidity, over 30 percent of the total intensity difference between the Earth and the LIM occurs in the heliosheath; 3. The 2 MeV protons studied here for the first time beyond the heliopause are also part of the low energy tail of the spectrum of galactic cosmic ray protons, similar to the tail noted above for sub MeV galactic cosmic ray electrons., Comment: 17 pages, 5 figures

Using Leaky Box Model propagation calculations for H nuclei and a Monte Carlo diffusion propagation model for electrons, starting from specific source spectra, we have matched the observed LIS spectra of these cosmic rays measured by Voyager at lower energies and AMS-2 at higher energies, a range from ~10 MeV to ~1 TeV. The source spectra required are very similar rigidity spectra. Below ~6-10 GV the source spectra for both particles are ~P-2.25 and above 10 GV the spectra are ~P-2.36-2.40. This break in the source spectral index is not seen for He and C nuclei in a match of Voyager and AMS-2 intensities both of which have source rigidity spectra with an index ~-2.24 throughout the entire range of measured energies from ~10 MeV//nuc to ~1 TeV/nuc. The absolute source intensities of electrons and H nuclei are derived and the source ratio of accelerated electrons to H nuclei is between 2-5%. The total number of accelerated electrons is much greater than that for protons, however, because the accelerated electron spectrum extends down to ~1-2 MV rigidity whereas the H nuclei spectrum cannot be observed below ~50-100 MV because of ionization energy loss. Most of these low energy electrons escape from the galaxy forming an intergalactic background., Comment: 18 pages, 5 figures, 1 table

This paper determines the relative source spectra of cosmic ray H and He nuclei using a Leaky Box model for galactic propagation and the observed spectra of these nuclei from ~10 MeV/nuc to ~1 TeV/nuc. The observations consist of Voyager 1 measurements up to several hundred MeV/nuc in local interstellar space and measurements above ~10 GeV/nuc where solar modulation effects are small by experiments on BESS, PAMELA and AMS-2. Using BESS and PAMELA measurements which agree with each other, the observed spectra for H and He nuclei and the H/He ratio are well fit by source rigidity spectra for both nuclei which are ~P-2.24 over the entire range of rigidities corresponding to energies between 10 MeV/nuc and several hundred GeV/nuc. In this case, the H/He rigidity source ratio is 5.0 + 1. The recent and presumably more accurate measurements of these spectra above 10 GeV/nuc made by AMS-2 do not entirely agree with the earlier measurements, however. In particular the H spectrum is found to be steeper than that of He by about 0.10 in the spectral exponent. Using the same model for galactic propagation the AMS-2 data leads to source spectra of H and He which are ~P-2.24 up to a break rigidity ~6-8 GV. At higher rigidities the He source spectrum continues to be ~P-2.24 but the required source spectrum for H steepens to an index ~P-2.36 above ~8 GV and, as a result, the H/He source ratio decreases with increasing rigidity using the AMS-2 data., Comment: 22 pages, 1 table, 6 figures

We have measured the intensity and spectra of the cosmic ray secondary isotopes 2H and 3He and the primary isotopes H and 4He between 20-85 MeV/nuc during a 5 year time period after Voyager 1 (V1) crossed the heliopause. The data reported here is from the B-end high energy telescope. The ratios of the intensities of the secondary to primary spectra of these nuclei at low energies are sensitive indicators for determining the amount of matter traversed at these energies by their galactic cosmic ray progenitor nuclei, after acceleration, in this case mostly 4He nuclei. The measurements of secondary 3He abundances indicate that cosmic ray 4He of energies between 30-100 MeV/nuc have traversed between 7-9 g/cm2 of interstellar matter (90% H, 10% He) in a Leaky Box propagation model. This path length is also consistent with the production of secondary 2H nuclei between 20-50 MeV/nuc, which is also produced mainly by 4He in a LBM. The Boron abundance, studied in separate papers, is also consistent with this path length at energies >30 MeV/nuc. These secondary intensities imply that the interstellar cosmic ray path length may be described in a LBM in a manner consistent with a mean path length,gamma= 20.6 beta P-0.45 at rigidities above ~0.5 GV (30 MeV/nuc for A/Z=2 nuclei). Both 2H and Boron have an excess intensity vs. the predictions for path lengths of 9 g/cm2 below 30 MeV/nuc., Comment: 22 pages, 8 figures, 2 tables

We have obtained the energy spectra of cosmic ray He, B, C, O, Mg, S and Fe nuclei in the range 0.5-1.5 GeV/nuc and above using the penetrating particle mode of the High Energy Telescope, part of the Cosmic Ray Science (CRS) experiment on Voyagers 1 and 2. The data analysis procedures are the same as those used to obtain similar spectra from the identical V2 HET telescope while it was in the heliosphere between about 23 and 54 AU. The time period of analysis includes 4 years of data beyond the heliopause (HP). These new interstellar spectra are compared with various earlier experiments at the same energies at the Earth to determine the solar modulation parameter, phi. These new spectra are also compared with recent measurements of the spectra of the same nuclei measured by the same telescope at low energies. It is found that the ratio of intensities at 100 MeV/nuc to those at 1.0 GeV/nuc are significantly Z dependent. Some of this Z dependence can be explained by the Z2 dependence of energy loss by ionization in the 7-10 g/cm2 of interstellar H and He traversed by cosmic rays of these energies in the galaxy; some by the Z dependent loss due to nuclear interactions in this same material; some by possible differences in the source spectra of these nuclei and some by the non-uniformity of the source distribution and propagation conditions. The observed features of the spectra, also including a Z dependence of the peak intensities of the various nuclei, pose interesting problems related to the propagation and source distribution of these cosmic rays., Comment: 35 pages, 5 tables, 14 figures

This paper examines the cosmic ray He and C nuclei spectra below ~1 GeV/nuc, as well as the very rapid increase in the He/C ratio below ~100 MeV/nuc, measured by Voyager 1 beyond the heliopause. Using a simple Leaky Box Model (LBM) for galactic propagation we have not been able to simultaneously reproduce the individual He and C nuclei spectra and the large increase in He/C ratio that is observed at low energies. However, using a truncated LBM with different truncation parameters for each nucleus that are related to their rate of energy loss by ionization which is ~Z2/A, these different features can be matched. This suggests that we are observing the effects of the source distribution of cosmic rays in the galaxy on the low energy spectra of cosmic ray nuclei and that there may be a paucity of nearby sources. In this propagation model we start very specific source spectra for He and C which are ~dj/dP = P-2.24, the same for each nucleus and also for all rigidities. These source spectra become spectra with spectral indices ~-2.69 at high rigidities for both charges as a result of a rigidity dependence of the diffusion coefficient governing the propagation which is taken to be ~P-0.45. This exponent is determined directly from the B/C ratio measured by AMS-2. These propagated P-2.69 spectra, when extended to high energies, predict He and C intensities and a He/C ratio that are within +3-5% of the intensities and ratio recently measured by AMS-2 in the energy range from 10 to 1000 GeV/nuc., Comment: 17 pages, 3 tables, 3 figures

We have used new measurements of the B/C ratio in galactic cosmic rays at both low and high energies by the Voyager and AMS-2 spacecraft, respectively, along with propagation calculations using a truncated LBM to examine the implications of these new measurements over an extended energy range from a few MeV/nuc to 1 TeV/nuc. We find that the predictions from both the truncated LBM and the Diffusive Reacceleration model for GALPROP both agree with the Voyager and AMS-2 measurements of the B/C ratio to within +/- 10 percent throughout the entire energy range from 50 MeV/nuc to 1 TeV/nuc. The two propagation approaches also agree with each other to within +/-10 percent or less throughout this energy range. In effect a diffusion model, without significant additional acceleration, provides a match within +/-10 percent to the combined data from Voyager 1 and AMS-2 on the B/C ratio from 50 MeV/nuc to 1 TeV/nuc. The B/C ratio below 50 MeV/nuc measured at V1 exceeds the predictions of both propagation models by as much as 3 sigma in the data measurement errors., Comment: 15 pages, 2 tables, 3 figures

We have derived background corrected intensities of 3-50 MeV galactic electrons observed by Voyager 1 as it passes through the heliosheath from 95 to 122 AU. The overall intensity change of the background corrected data from the inner to the outer boundary of the heliosheath is a maximum of a factor ~100 at 15 MeV. At lower energies this fractional change becomes less and the corrected electron spectra in the heliosheath becomes progressively steeper, reaching values ~ -2.5 for the spectral index just outside of the termination shock. At higher energies the spectra of electrons has an exponent changing from the negative LIS spectral index of -1.3 to values approaching zero in the heliosheath as a result of the solar modulation of the galactic electron component. The large modulation effects observed below ~100 MV are possible evidence for enhanced diffusion as part of the modulation process for electrons in the heliosheath., Comment: 28 pages, 2 tables, 13 figures

We have determined the solar modulation potential, phi, vs. time that is observed at Voyager 1 and 2 from measurements of the H and He nuclei intensities at a common energy of 250 MeVnuc. The H nuclei have a rigidity 0.7 GV, the He nuclei 1.4 GV. These measurements cover a 40 year time period, which includes almost 4 cycles of solar 11 year sunspot variations, throughout the inner heliosphere out to the HTS at distances of 95 AU and 85 AU, respectively at V1 and V2, and then beyond in the heliosheath. Inside the HTS the modulation potential vs. time curves at V1 and V2 show a very similar temporal structure to those observed at the Earth. During a later period of maximum solar modulation from 2000.0 to 2005.0 when V1 and V2 are in the outer heliosphere between 60-94 AU, the main temporal features of the modulation potential curves at all 3 locations match up with appropriate time delays at V1 and V2 if it is assumed that spatially coherent structures are moving outward past V1 and V2, with outward speeds of up to 700 Kms negative 1. After 2004.0 V1 and V2 are at latitudes of positive 35 and negative 30 respectively, placing lower limits on the latitude extent of these structures. Beyond the HTS in the heliosheath the modulation potential slowly decreases at both spacecraft with only a weak evidence of the unusual modulation minimum observed at the Earth in 2009, for example. A sudden decrease of the modulation potential 50 MV for both H and He nuclei occurs at V1 just before the heliopause crossing at about 122 AU. This decrease has not yet been observed at V2, which is now at 113 AU and still observing a modulation potential 60 MV., Comment: 28 pages, 9 Figures

The cosmic ray electrons measured by Voyager 1 between 3-70 MeV beyond the heliopause have intensities several hundred times those measured at the Earth by PAMELA at nearly the same energies. This paper compares this new V1 data with data from the earth-orbiting PAMELA experiment up to energies greater than 10 GeV where solar modulation effects are negligible. In this energy regime we assume the main parameters governing electron propagation are diffusion and energy loss and we use a Monte Carlo program to describe this propagation in the galaxy. To reproduce the new Voyager electron spectrum, which is E-1.3, together with that measured by PAMELA which is E-3.20 above 10 GeV, we require a diffusion coefficient which is P 0.45 at energies above 0.5 GeV changing to a P-1.00 dependence at lower rigidities. The entire electron spectrum observed at both V1 and PAMELA from 3 MeV to 30 GeV can then be described by a simple source spectrum, dj/dP P-2.25, with a spectral exponent that is independent of rigidity. The change in exponent of the measured electron spectrum from -1.3 at low energies to 3.2 at the highest energies can be explained by galactic propagation effects related to the changing dependence of the diffusion coefficient below 0.5 GeV, and the increasing importance above 0.5 GV of energy loss from synchrotron and inverse Compton radiation, which are both E2, and which are responsible for most of the changing spectral exponent above 1.0 GV. As a result of the P-1.00 dependence of the diffusion coefficient below 0.5 GV that is required to fit the V1 electron spectrum, there is a rapid flow of these low energy electrons out of the galaxy. These electrons in local IG space are unobservable to us at any wave length and therefore form a dark energy component which is 100 times the electrons rest energy., Comment: 21 Pages, 8 Figures

Voyager observations for over 3 years beyond the heliopause have started to define features of the low energy, less than 100 MeV per nuc, cosmic ray secondary nuclei that have a zero or negligibly small source component. As an example, the abundance of B between about 7 and 15 MeV per nuc is unexpectedly large, greater than the prediction of a LBM by 2 or 3 in the measurement and cross section error. On the other hand, for several other heavier secondary nuclei with a low source abundance such as F and Z equal 17 to 19 and 21 to 23 nuclei, in the corresponding energy channels between about 10-20 MeV/nuc, zero nuclei have been observed. The same LBM calculations would predict about 6 to 7 events for the sum of these three groups of nuclei. The B observed intensities could be more closely matched by considering a nested LBM with 0.3-1.0 g/cm2 of matter near the cosmic ray sources, essentially a source component of B. This nested LBM calculation, if extended to the production of the above groups of secondaries, would however predict a total 8 to 12 events thus leading to an even larger discrepancy with the zero events that are observed. The measurements of heavier secondaries at low energies therefore make it very problematical that a nested LBM with more than a few 0.1 g/cm2 or more of matter near the sources could be the source of the large B abundance seen by Voyager. The large abundance of B at the lowest energies is best understood, so far, as the result of production mostly from a matter traversal of 10 g/cm2 in the galaxy, possibly in combination with uncertainties in the data and cross sections at these low energies., Comment: 16 pages, 7 figures

This paper seeks to find an explanation of the galactic cosmic ray B/C ratio newly measured in cosmic rays between ~10 MeV/nuc and 1 TeV/nuc. Voyager measurements of this ratio at low energies and AMS-2 measurements at high energies are used in this study. These measurements both considerably exceed at both low and high energies the ratio predicted using a simple Leaky Box Model for propagation of cosmic rays in the galaxy. Between 1-70 GeV/nuc, however, this same model provides an excellent fit (within +2-3%) to the new AMS-2 measurements using an escape length ~P-0.45. This would imply a diffusion coefficient ~P0.45, very close to the Kraichian cascade value of 0.50 for the exponent. Extending this same diffusion dependence to high energies, still in a LBM, along with a truncation of short path lengths in the galaxy will predict a B/C ratio of 4.5% at ~800 GeV/nuc which is very close to the AMS-2 measurement at that energy. This would indicate that the amount of material traversed near the source in a Nested LBM, for example, is less than about 0.5 g/cm2 at these energies since this process, with additional matter near the sources, would increase the B/C ratio. At low energies, however, the B/C ratio of 14% +3% at ~10 MeV/nuc measured by Voyager is more difficult to explain. The same parameters used in a LBM that fit the high energy B/C measurements predicts a B/C ratio of only ~4% at 10 MeV/nuc where the path length is about 1.5 g/cm2. If the cosmic rays have traversed ~10 g/cm2 of material in the galaxy at low energies the prediction for B/C is still only 8%, which is between 2.0-3.0 sigma below the measurement and its errors., Comment: 14 pages, 3 figures

We have determined the interstellar spectra of cosmic ray protons and electrons from a few MeV to ~10 GeV. These interstellar spectra are based on Voyager data and a normalization of specific galactic propagation model calculations of both protons and electrons to PAMELA data at the Earth at 10 GeV, where the solar modulation is small. These resulting interstellar spectra are then compared with spectra of protons and electrons measured at lower energies at the Earth by PAMELA in 2009. The total amount of modulation at lower rigidities (energies) is found to be nearly the same at the same rigidity for both protons and electrons and ranges in magnitude from a factor ~400 at 0.1 GV for electrons, to a factor ~15 at 0.44 GV (100 MeV for protons), to a factor ~3.3 at 1 GV for both components. The magnitude of this total modulation of both components are the same to within + 10% from ~0.3 to ~3 GV in rigidity. The observed total modulation for protons can be matched quite closely using a simple spherically symmetric modulation picture involving a force field model for the modulation and a constant energy loss at all energies. The electrons require a set of parameters to calculate more detailed features of the modulation using the diffusion coefficient and its variation with rigidity and radius at rigidities less than few GV., Comment: 15 pages, 4 figures

The intensities of the low energy part of the spectra of primary cosmic ray nuclei including C, O, Ne, Mg, Si and Fe measured by Voyager 1 beyond the heliopause are deficient relative to the spectra measured at energies above ~100 MeV/nuc as calculated using a standard Leaky Box Model with the path length a function of rigidity. Modifications to the normal exponential distribution of path lengths at a single rigidity as is used in a simple LBM will provide a good fit to this new Voyager 1 data at low energies. These modifications, sometimes called a truncation, lead to a deficiency of short path lengths relative to an exponential distribution. This deficiency in the intensities can be described by a truncation parameter = 0.12. This modification can be produced in several ways including a non-uniform local distribution of cosmic ray sources. A uniform source distribution in the galactic plane that is deficient in sources within 0.2-0.4 Kpc of the Sun is indicated by the data. Further studies of these low energy spectra in more detail will improve these estimates and help define other features of the local galactic distribution of these cosmic rays., Comment: 17 pages, 5 figures

Uncertainties in the Voyager data itself as well as the cross sections for production of these secondaries at these low energies are an important limitation on the estimates of the amount of matter traversed. We also attempt a fit to the B observations at low energies by considering a source component of B generated in 1.0 g/cm2 of matter near the sources but after acceleration. This would be equivalent to a Nested LBM. In this model the V1 data below 40 MeV/nuc is now well fit. For Nitrogen, which is dominated by a source component at these low energies, a fit to the data between 10-130 MeV/nuc can be obtained with a N/O source ratio = 6.3 + 1.0% and a path length compatible with the H and He propagation as noted above. This Voyager observation confirms earlier measurements of a low N abundance in the cosmic ray source relative to what is found for solar abundances, for example, where the N/O ratio is found to be ~12%., Comment: 15 pages, 1 table, 4 figures

The large intensity of greater than 10 GeV positrons which apparently come from sources outside the Earth-Sun system observed recently by many spacecraft (PAMELA, FERMI, AMS2) is still a mystery with broad implications. In our attempts to solve this mystery we have first tried to define reasonable limits to the positrons produced in our own galaxy by nuclear interactions of cosmic rays. This is best done by using the secondary B/C ratio produced by these same cosmic rays in order to define the amount of matter traversed by galactic cosmic ray nuclei. Using new values of the B/C ratio together with earlier calculations of positron production by Moskalenko and Strong, 1998, we find that at 10 GeV this galactic production is from 70% to almost 100% of the positrons observed by the above experiments. At 100 GeV these fractions are still from 20 to 33% of the positrons observed. The resulting excess positron spectrum above this normal galactic background is found to have an exponent -2.75, possibly flattening at lower energies. If these positrons are coming to us from a uniform source distribution in and beyond the disk of the galaxy with a source spectrum that is E-2.0, a spectral steepening caused by synchrotron and inverse Compton losses, which are largest near the galactic plane, will produce a spectrum E-2.75 at the Earth. This is similar to the excess spectrum we find. The excess positron spectrum E-2.75 that we obtain is also very similar to the positron spectrum produced by galactic protons in the Earths atmosphere and in the spacecraft itself which also has a spectrum E-2.75. This results in a background for all the above experiments. The assumption is that this type of background is removed by the stringent criteria that are imposed on each event. This calculation needs to be reconsidered before the implications of these important positron results can be fully evaluated., Comment: 12 pages, 3 figures

In this paper we fit the observed galactic cosmic ray electron spectrum from a few MeV to 1 TeV. New data from Voyager from 5-60 MeV beyond the heliopause is used along with high energy data from the PAMELA, FERMI and AMS-2 instruments in Earth orbit. Using a Monte Carlo diffusion model for galactic propagation we obtain a source rigidity spectrum with a spectral index =-2.25 independent of energy below 10 GeV, possibly steepening above 10 GeV to 2.40 at the highest energies. This spectrum will fit the electron data over 5 orders of magnitude to within + 10% at both low and high energies. This steepening of the electron source spectrum could be an important feature of the acceleration process, e.g., synchrotron loss during acceleration could steepen the source spectrum. This fit requires only a single break in the rigidity dependence of the diffusion coefficient by ~1.0 power in the exponent at about 1.0 GV. The calculations also predict the distribution of electrons perpendicular to the galactic disk. The galaxy does act as a calorimeter for electrons in the energy range 0.1-10 GeV where ~80% of the electrons are trapped. At higher energies the electrons escape the galactic disk rapidly. At energies ~1 TEV the electrons loose most of their energy by synchrotron and inverse Compton emission within < 0.5 Kpc of their origin near the galactic equator. At energies < 0.1 GeV, because of the increase in the diffusion coefficient below ~1 GV, and the absence of other significant loss processes, the electrons escape and form a difficult to detect, but important galactic halo population., Comment: 18 pages,5 figures

Utilizing new Voyager measurements at lower energies and higher energy spacecraft measurements near the Earth, the interstellar spectra of primary cosmic ray nuclei from H to Fe have now been determined from ~10 MeV/nuc to > 100 GeV/nuc. These measurements are compared with the predictions from a Leaky Box propagation model. It is found that above ~50-100 MeV/nuc the spectra of all the nuclei, H, He, C, O, Ne, Mg, Si and Fe are well connected between 100 MeV/nuc and 10 GeV/nuc and above by simple source rigidity spectra proportional to P-2.28, with the exponent independent of rigidity and using a rigidity dependent diffusion coefficient ~P0.50 above ~1.0 GV. This leads to intensities and spectra ~P-2.78 at ~100 GeV/nuc and above, which are consistent with new AMS-2 and PAMELA measurements of H, He and C to within + 10%. Below 50-100 MeV the spectra of these primary charges fall into two groups. The spectra of primary nuclei with Z > 6 fall more rapidly at low energies than those of H and He and more rapidly than would be expected from a pure diffusive LBM, where energy loss by ionization is important at low energies. Increasing the fraction of ionized hydrogen in the interstellar medium from 15% to 30% does not satisfactorily explain the systematics of the intensity decreases of the heavier primary nuclei at low energies. Other processes beyond those assumed in a simple leaky box model, such as a lack of cosmic ray sources near the Sun are being investigated as the source of this more rapid intensity decrease of these nuclei. The spectra of H and He are very similar to each other but both contain more low energy particles than would be expected from a correspondence with the heavier nuclei spectra. We believe that this may indicate the presence of a local (heliospheric) component of these nuclei in addition to the galactic component., Comment: 20 pages, 8 figures

A comparison of the Helium and Carbon interstellar spectra measured at Voyager in the local interstellar medium leads to a different interpretation than a comparison of the Hydrogen to Helium spectra. This is because the He/C ratio is observed to increase rapidly with energy below 40 MeV/nuc in contrast to an almost constant H/He ratio at these low energies. Both the He and C spectra that are observed at Voyager above 40 MeV/nuc and much higher energy spectra from the PAMELA measurements of these two components up to 100 GeV/nuc can be accurately fit to within 10% assuming galactic propagation in a leaky box type of diffusion model in the galaxy with identical source spectra P-2.28 for He and C using a diffusion coefficient P0.50 above 1 GV rigidity. These same exponents also fit the H spectrum from 40 MeV to over 100 GeV. At low energies an excess of He relative to C is observed that would amount to about 20% of the modeled galactic component at 10 MeV/nuc., Comment: 12 pages, 2 figures

Voyager 1 data from beyond the heliopause provide the first direct measurements of the interstellar cosmic ray spectra below 1 GeVnuc. In this paper we combine these Voyager measurements of H and He nuclei from 3-600 MeVnuc with higher energy measurements at 1 AU from the BESS and PAMELA experiments up to 100 GeVnuc. Using a Weighted Leaky Box Model for propagation in the galaxy, we obtain an excellent fit to these new Voyager observations and the much higher energy spectra up to 100 GeVnuc by using source spectra which are P-2.28, with the exponent independent of rigidity from low to high rigidities; along with a rigidity dependence of the diffusion path length which is P-0.5 at rigidities 1.00 GV, and possibly changing to P1.0 at lower rigidities., Comment: 19 pages, 5 figures

Using data from the Voyager 1 and 2 CRS telescopes available on the web through the end of 2014 we have studied the intensity variations of termination shock H nuclei and anomalous cosmic ray H and He nuclei as a function of radial distance. In contrast to the inner part of the heliosheath where the intensity vs. radius profiles in the North and South heliosheaths are much different, these intensity vs. radius profiles, as well as the intensities themselves, are more similar in the outer North and South heliosheaths as measured by V1 and V2 respectively. In the N heliosheath, taken to be 27.6 AU thick beyond the HTS crossing distance of 94 AU, the intensities of termination shock particles and anomalous cosmic rays reach a maximum at between 110-112 AU or at a location ~halfway between the termination shock and the heliopause. They then decrease more or less continuously to an intensity ~2/3 of the maximum for each component just before the final dropout at ~121 AU, just inside the heliopause. This intensity-time behavior favors theories in which the acceleration and loss effects lead to a maximum near the middle of the heliosheath., Comment: 14 pages, 3 figures

We have used corresponding marker features in the intensity vs. time profile of termination shock particles coming from within the heliosheath and also 5-12 MeV electrons which are coming from beyond the heliopause that are both observed at both V1 and V2 in the outer N and S heliosheaths, to estimate the thickness of the S heliosheath. These features in the N heliosheath have been observed on the CRS instrument on V1 in the N heliosheath beyond 110 AU or within 12 AU of the heliopause. Although the intensity-time features in the S heliosheath are quite different overall, certain features stand out at both V1 and V2. The correspondence of these features in the N and S heliosheath allows us to estimate that V2 will reach the S heliopause near the end of 2014., Comment: 8 pages, 3 figures

We discuss two extraordinary increases of cosmic ray intensity observed by Voyager 1 in the last 1.1 AU before heliopause crossing, Aug 2012 at 121.7 AU. The two increases are roughly similar in amplitude and result in a total increase of cosmic ray nuclei around 1 GV of over 50 percent and of 0.01 GV electrons of a factor about 2. During the first increase, the changes in the magnetic, B, field are small. After the first increase, the B field variations and cosmic ray changes become large and during the second increase the B field variations and the cosmic ray changes are correlated to within a day. The intensity variations of H and He nuclei during these time intervals are measured from 0.1 to over 1 GV. The total GCR increse over the two events resemble those expected from a simple force-field 'like' solar modulation model with a modulation potential of about 80MV. This is nearly one third of the total modulation potential of about 250 GV required to produce the modulation of these particles observed at the earth at the 2009 sunspot minimum and adds a new aspect to ideas about heliospheric modulation., Comment: 11 pages, 3 figures

Voyager 1 has explored the solar wind-interstellar medium interaction region between the terminal shock and heliopause following the intensity distribution of galactic cosmic ray protons above 200 MeV energy. Before this component reached the galactic level at 121.7 AU, 4 episodes of rapid intensity change occured similar to the Forbush Decreases found near the sun, rather than the expected result of models related to those describing Long Term Modulation in the inner solar system. Because the mean solar wind flow is both expected and observed to be perpendicular to the radial direction close to the heliopause, explanation is given in terms of transient radial flows related to possible heliopause boundary flapping. It is necessary that radial flows are at the sound speed found for conditions downstream of the teminal shock and that the relevant perpendicular cosmic ray diffusion is controlled by 'slab' field fluctuations accounting for 20 percent or less of the total power in field variance. However, additional radial drift motion related to possible north to south gradients in the magnetic field may allow the inclusion of some diffusion according to 2-D turbulence theory. The required field gradients may arise due to variation in the field carried by the solar plasma deflected away from the solar equatorial plane. Modulation amounting to a total 30 percent drop in galactic intensity requires explanation by a combination of several transient episodes., Comment: 14 pages

The paper describes differences in the intensity as a function of radial distance of anomalous and galactic cosmic rays in the N-S heliosheaths as observed by the Voyager 1 and 2 spacecraft respectively. The anomalous cosmic ray (ACR) intensities above a few MeV in the N heliosheath reach a maximum at ~2009.5, about 16 AU beyond the heliospheric current sheet (HTS), thus indicating a possible source location for these higher energy particles. The galactic cosmic ray electron and nuclei intensities continue to increase rapidly throughout the entire N-heliosheath out to 121.7 AU. Two sudden increases of these electrons at 16.6 and 22.2 AU beyond the HTS suggest that the V1 spacecraft passed significant heliosheath structures at these times. Later, at 121.7 AU, which is a distance of 27.6 AU beyond the initial HTS crossing distance, V1 in the N heliosheath appears to pass beyond the ACR trapping region as the anomalous particles disappear suddenly and completely. At V2 in the S heliosheath, large 42-21 day periodic intensity variations were observed for a few MeV particles just beyond the HTS crossing distance at 83.7 AU and again about a year later when V2 was ~4 AU beyond this shock. These are the dominant features of the energetic particle populations in the inner part of the S-heliosheath. The ACR and electrons later decreased to almost background levels until a sudden increase at 2011.25, at a distance of about 10 AU beyond the HTS. The features observed by V2 in the S heliosheath relative to those at V1 indicate a much more structured S heliosheath in which the latitude of V2 relative to the HCS maximum latitude (sector zone) may play an important role. Estimates of a S heliosheath trapping/modulation boundary for energetic particles in the range 105-110 AU are obtained in this paper from a comparison with those at 121.7 AU observed in the N hemisphere., Comment: 28 pages, 7 Figures

The new Voyager measurements of cosmic ray electrons between 6-60 MeV beyond 122 AU are very sensitive indicators of cosmic ray propagation and acceleration in the galaxy at a very low modulation level. Using a Monte Carlo diffusion model with a source spectrum with a single spectral index of -2.2 at all energies we are able to fit this observed Voyager spectrum and the contemporary PAMELA electron spectrum over an energy range from 6 MeV to ~200 GeV. This spectrum has a break in it but this break is due to propagation effects, not changes in the primary spectrum. This break is gradual, starting at > 2 GeV where the spectrum is ~E^-3.2 and continuing down to ~100 MeV or below where the spectrum becomes ~E^-1.5. At the higher energies the loss terms due to synchrotron radiation and inverse Compton effects which are ~E^2.0 steepen the exponent of the source spectrum by 1.0. At lower energies, these terms become unimportant and the loss is governed by diffusion and escape from the galaxy. A diffusion term which is proportional to beta^-1 below ~0.32 GV (which also fit the H and He spectra measured at Voyager) and has a value = 3x1028 cm^2 x s^-1 at 1 GV and a boundary at +/-1 Kpc will fit the Voyager or other similar spectra at low energies., Comment: 9 pages, 4 figures

After the disappearance of lower energy heliospheric particles at Voyager 1 starting on August 25th, 2012, spectra of H, He and C/O nuclei were revealed that resembled those to be expected for galactic cosmic rays. These spectra had intensity peaks in the range of 30-60 MeV, decreasing at both lower energies down to a few MeV and at higher energies up to several hundred MeV. We have modeled the propagation of these particles in the galaxy using an updated Leaky Box Diffusion model which determines the spectra of these components from ~2 MeV to >200 GeV. The key parameters used in the model are a galactic input spectrum ~P^-2.24, the same for all components and independent of rigidity, and a diffusion coefficient that is ~P^0.5 above a lower rigidity and increases ~beta^-1.0 below a lower rigidity ~0.56 GV. These same parameters also fit the high energy H and He data from ~10-200 GeV/nuc from the PAMELA and BESS experiments. The new Voyager spectra for all three nuclei are thus consistent with rigidity spectra ~P^-2.24 from the lowest energies to at least 100 GeV. Deviations from this spectrum can reasonably be attributed to propagation effects. Some deviations between the calculated and newly observed spectra are noted, however, below ~30 MeV/nuc, particularly for C/O nuclei, that could be significant regarding the propagation and sources of these particles., Comment: 12 pages, 7 figures

This paper describes the unfolding of the solar modulated galactic cosmic ray H and He nuclei spectra beyond ~105 AU in the heliosheath. Between 2008.0 and 2012.3 when Voyager 1 went from about 105 to 120.5 AU the spectral intensities of these two components between about 30 and 500 MeV/nuc unfolded (increased) in a manner consistent with an average modulation potential decrease ~5 MV per AU as described by a Parker like cosmic ray transport in the heliosphere where the overall modulation is described by a modulation potential in MV. Between 120.5 and 121.7 AU, however, as a result of two sudden intensity increases starting on May 8th and August 25th, 2012, this modulation potential decreased by ~80 MV and spectra resembling possible local interstellar spectra for H and He were revealed. Considering these spectra to be the local interstellar spectra would imply that almost 1/3 of the total modulation potential of about 270 MV required to explain the spectra of these components observed at the Earth must occur in just a 1 AU radial interval in the outer heliosheath. As a result about ~80% of the total modulation potential observed at the Earth at this time occurs in the heliosheath itself. The remaining 20% of the total modulation occurs inside the heliospheric termination shock. The details of these intensity changes and their description by a simple modulation model are discussed., Comment: 21 pages, 6 figures

Voyager 1 has explored the solar wind-interstellar medium interaction region between the Terminal Shock and the Heliopause, following the intensity distribution of the shock accelerated anomalous component of cosmic rays in the MeV energy range. The sudden disappearance of this component at 121.7 AU from the sun is discussed in terms of three models for the transition into the interstellar plasma flow. Particles trapped flowing parallel to the boundary may penetrate up to one Larmour radius beyond. If the boundary is stationary, Voyager 1 directly samples this distance. The boundary could flap, depending on Heliosheath pressure changes and Voyager 1 then samples the extent of this motion. Finally, a turbulent boundary layer is considered in which the MeV particle distribution falls off with distance, thus measuring diffusion within the layer., Comment: 5 pages

At the Voyager 1 spacecraft in the outer heliosphere, after a series of complex intensity changes starting at about May 8th, the intensities of both anomalous cosmic rays (ACR) and galactic cosmic rays (GCR) changed suddenly and decisively on August 25th (121.7 AU from the Sun). The ACR started the intensity decrease with an initial e-folding rate of intensity decrease of ~1 day. Within a matter of a few days, the intensity of 1.9-2.7 MeV protons and helium nuclei had decreased to less than 0.1 of their previous value and after a few weeks, corresponding to the outward movement of V1 by ~0.1 AU, these intensities had decreased by factors of at least 300-500 and are now lower than most estimates of the GCR spectrum for these lower energies and also at higher energies. The decrease was accompanied by large rigidity dependent anisotropies in addition to the extraordinary rapidity of the intensity changes. Also on August 25th the GCR protons, helium and heavier nuclei as well as electrons increased suddenly with the intensities of electrons reaching levels ~30-50% higher than observed just one day earlier. This increase for GCR occurred over ~1 day for the lowest rigidity electrons, and several days for the higher rigidity nuclei of rigidity ~0.5-1.0 GV. After reaching these higher levels the intensities of the GCR of all energies from 2 to 400 MeV have remained essentially constant with intensity levels and spectra that may represent the local GCR. These intensity changes will be presented in more detail in this, and future articles, as this story unfolds., Comment: 13 Pages, 5 Figures

We have examined features in the structure of the heliosheath using the fine scale time variations of termination shock particles (TSP) between ~0.5 - 20 MeV and electrons between 2.5-14 MeV measured by the CRS instrument as the V2 spacecraft crossed the heliospheric termination shock in 2007. The very disturbed heliosheath at V2 is particularly noteworthy for strong periodic intensity variations of the TSP just after V2 crossed the termination shock (2007.66) reaching a maximum between 2007.75 and 2008.0. A series of 42/21 day periodicities was observed at V2 along with spectral changes of low energy TSP and the acceleration of 6-14 MeV electrons. Evidence is presented for the acceleration of TSP and electrons at the times of the 42/21 day periodicities just after V2 crossed the HTS. Spectra for TSP between 2-20 MeV and electrons between 2.5-14 MeV are derived for three time periods including the time of the HTS crossing. The energy spectra of TSP and electrons at these times of intensity peaks are very similar above ~3 MeV, with exponents of a power law spectrum between -3.0 and -3.6. The ratio of TSP intensities to electron intensities at the same energy is ~500. The electron intensity peaks and minima are generally out of phase with those of nuclei by ~1/2 of a 42 day cycle. These charge dependent intensity differences and the large periodic intensity changes could provide new clues as to a possible acceleration mechanism., Comment: 18 pages, 4 Figures

The recovery of cosmic ray Carbon nuclei of energy ~20-125 MeV/nuc in solar cycle #23 from 2004 to 2010 has been followed at three locations, near the Earth using ACE data and at V2 between 74-92 AU and also at V1 beyond the heliospheric termination shock at between 91-113 AU. To describe the observed intensity changes and to predict the absolute intensities measured at all three locations we have used a simple spherically symmetric (no drift) two-zone heliospheric transport model with specific values for the diffusion coefficient in both the inner and outer zones. The diffusion coefficient in the outer zone is determined to be ~5-10 times smaller than that in the inner zone out to 90 AU. For both V1 and V2 the calculated C nuclei intensities agree within an average of \pm 10% with the observed intensities. Because of this agreement between V1 and V2 observations and predictions there is no need to invoke an asymmetrical squashed heliosphere or other effects to explain the V2 intensities relative to V1 as is the case for He nuclei. The combination of the diffusion parameters used in this model and the interstellar spectrum give an unusually low overall solar modulation parameter \phi = 250 MV to describe the Carbon intensities observed at the Earth in 2009. At all times both the observed and calculated spectra are very closely ~ E1.0 as would be expected in the adiabatic energy loss regime of solar modulation., Comment: 12 pages, 10 figures

Voyager 1 has entered regions of different propagation conditions for energetic cosmic rays in the outer heliosheath beginning at a distance of about 111 AU from the Sun. This conclusion is based on the fact that the low energy 6-14 MeV galactic electron intensity suddenly increased by ~20% over a time period \leg 10 days and the electron radial intensity gradient abruptly decreased from ~19%/AU to ~8%/AU at 2009.7 at a radial distance of 111.2 AU. A sudden radial gradient change was also observed at this time for >200 MeV protons. The gradients were constant during the time period before and after the electron increase. At about 2011.2 at a distance of 116.6 AU a second abrupt intensity increase was observed, this time for both electrons and protons. The increase for electrons was ~25% and occurred over a time period ~15 days or less. For >200 MeV protons the increase at this time was ~5% (unusually large) and occurred over a longer time period ~50 days. Between about 2011.2 and 2011.6, radial intensity gradients ~18%/AU and 3%/AU were observed for electrons and protons, respectively. These gradients were very similar to those observed for these particles before the 1st sudden increase at 2009.7. These large positive gradients observed after 2011.2 indicate that V1, although it has entered a different propagation region, is still within the overall heliospheric modulating region at least up to a time ~2011.6 (118.0 AU). In this paper we will discuss these events in more detail and consider possibilities for their explanation that have recently been suggested., Comment: 13 pages, 2 figures

The recovery of cosmic ray protons of energy ~150-250 MeV/nuc in solar cycle #23 from 2004 to 2010 has been followed at the Earth using IMP, ACE and balloon data and also at V2 between 74-92 AU and at V1 beyond the heliospheric termination shock (91-113 AU). The correlation coefficient between the intensities the Earth and V1 during this time period, is 0.936, allowing for a ~0.9 year delay due to the solar wind propagation time from the Earth to the outer heliosphere. To describe these intensity changes and to predict the absolute intensities measured at all three locations we have used a simple spherically symmetric (no drift) two-zone heliospheric transport model with specific values for the diffusion coefficient in both the inner and outer zones. The diffusion coefficient in the outer zone, from about 90 to 120 (130) AU, is determined to be ~5-10 times smaller than that in the inner zone out to 90 AU. This means that the outer zone acts much like a diffusing barrier in this model. The absolute magnitude of the intensities and the intensity changes at V1 and the Earth are described to within a few percent by a diffusion coefficient that varies with time by a factor ~4 in the inner zone and only ~1.8 (1.25) in the outer zone over the time period from 2004-2010. These diffusion coefficients and their variations are essentially the same as those derived earlier from a similar study using He nuclei of the same energy. This model and the diffusion coefficients used provide a total modulation potential at the Earth ~250 MV in 2009. The difference ~10-20% between calculated and observed intensities at V2 can be explained if the heliosphere is squashed by ~10% in distance (non-spherical) so that the HTS is closer to the Sun in the direction of V2 compared to V1., Comment: 20 Pages, 7 figures

The recovery of cosmic ray He nuclei of energy ~150-250 MeV/nuc in solar cycle #23 from 2004 to 2010 has been followed at the Earth using IMP and ACE data and at V2 between 74-92 AU and also at V1 beyond the heliospheric termination shock (91-113 AU). The correlation coefficient between the intensities at the Earth and at V1 during this time period is remarkable (0.921), after allowing for a ~0.9 year delay due to the solar wind propagation time from the Earth to the outer heliosphere. To describe the intensity changes and to predict the absolute intensities measured at all three locations we have used a simple spherically symmetric (no drift) two-zone heliospheric transport model with specific values for the diffusion coefficient in both the inner and outer zones. The diffusion coefficient in the outer zone, assumed to be the heliosheath from about 90 to 120 (130) AU, is determined to be ~5 times smaller than that in the inner zone out to 90 AU. This means the Heliosheath acts much like a diffusing barrier in this model. The absolute magnitude of the intensities and the intensity changes at V1 and the Earth are described to within a few percent by a diffusion coefficient that varies with time by a factor ~4 in the inner zone and only a factor of ~1.5 in the outer zone over the time period from 2004-2010. For V2 the observed intensities follow a curve that is as much as 25% higher than the calculated intensities at the V2 radius and at times the observed V2 intensities are equal to those at V1. At least one-half of the difference between the calculated and observed intensities between V1 and V2 can be explained if the heliosphere is squashed by ~10% in distance (non-spherical) so that the HTS location is closer to the Sun in the direction of V2 compared to V1., Comment: 13 Pages, 8 Figures

We have extended our earlier calculations of the distance to the Heliospheric Termination Shock (HTS) - which covered the period from the launch of V1 and V2 in 1977 to 2005 - to the period from 2006 to 2011. During this latter period the solar wind speed, ram pressure and magnetic field decreased to the lowest levels in recent history, related to the sunspot minimum in 2008-2009. The HTS distance has decreased correspondingly so that V1, which was crossed by the HTS at 94 AU in late 2004, would now, in early 2011, be expected to reach the HTS at a distance ~80 AU, when the HTS distance would be expected to be at its minimum. Similarly V2, which was crossed by the HTS at 84 AU in mid 2007, would, in early 2011, reach the HTS at a distance of only 74 AU. These distances, in early 2011, are ~15% less than those at which V1 and V2 initially reached the HTS. The distance to the Heliopause (HP) is more uncertain but recent calculations place its equilibrium distance at between 1.4-1.6 times the HTS distance. Allowing for an additional 1 year for the HP to reach its equilibrium minimum distance relative to the HTS would mean that, assuming this distance remains a constant fraction larger than the HTS distance, the HP distance would be at its minimum distance of (1.4-1.6) x 80 AU = 112-128 AU at V1 in early 2012. At this time V1 will be at a distance of ~120 AU so that there is a possibility that V1 could cross the HP and enter interstellar space at the time 2012.0 \pm 1 year. If the crossing does not happen during this time period, then it is unlikely that V1 will reach this defining boundary before about 2016 because of the expected outward motion of the HTS and the HP towards their more normal distances of 85-96 and ~120 -140 AU coincident with the maximum of the new sunspot cycle., Comment: 23 pages including 7 figures

We have compared the yearly production rates of 10Be by cosmic rays in the Earths polar atmosphere over the last 50-70 years with 10Be measurements from two separate ice cores in Greenland. These ice cores provide measurements of the annual 10Be concentration and 10Be flux levels during this time. The scatter in the ice core yearly data vs. the production data is larger than the average solar 11 year production variations that are being measured. The cross correlation coefficients between the yearly 10Be production and the ice core 10Be measurements for this time period are <0.4 in all comparisons between ice core data and 10Be production, including 10Be concentrations, 10Be fluxes and in comparing the two separate ice core measurements. In fact, the cross correlation between the two ice core measurements, which should be measuring the same source, is the lowest of all, only ~0.2. These values for the correlation coefficient are all indicative of a "poor" correlation. The regression line slopes for the best fit lines between the 10Be production and the 10Be measurements used in the cross correlation analysis are all in the range 0.4-0.6. This is a particular problem for historical projections of solar activity based on ice core measurements which assume a 1:1 correspondence. We have made other tests of the correspondence between the 10Be predictions and the ice core measurements which lead to the same conclusion, namely that other influences on the ice core measurements, as large as or larger than the production changes themselves, are occurring. These influences could be climatic or instrumentally based. We suggest new ice core measurements that might help in defining more clearly what these influences are and-if possible-to correct for them., Comment: 24 pages, 6 figures

Using new calculations of 10Be production in the Earths atmosphere which are based on direct measurements of the 11-year solar modulation effects on galactic cosmic rays and spacecraft measurements of the cosmic ray energy spectrum, we have calculated the yearly average production of 10Be in the Earths atmosphere by galactic and solar cosmic rays since 1939. During the last six 11-year cycles the average amplitude of these production changes is 36%. These predictions are compared with measurements of 10Be concentration in polar ice cores in both the Northern and Southern hemisphere over the same time period. We find a large scatter between the predicted and measured yearly average data sets and a low cross correlation ~0.30. Also the normalized regression line slope between 10Be production changes and 10Be concentration changes is found to be only 0.4-0.6; much less than the value of 1.0 expected for a simple proportionality between these quantities, as is typically used for historical projections of the relationship between 10Be concentration and solar activity. The distribution of yearly averages in the 10Be concentration level in the data from the Dye-3 ice core in Greenland for the time period 1939-1985, contains a "spike" of high concentration one year averages which is not seen in the production calculations. These and other features suggest that galactic cosmic ray intensity changes which affect the production of 10Be in the Earths atmosphere are not the sole source of the 10Be concentration changes and confirm the importance of other effects, for example local and regional climatic effects, which could be of the same magnitude as the 10Be production changes., Comment: 17 pages, 3 figures

We have examined instigating events at the Sun that may be responsible for two of the most recent outer heliospheric kHz emissions detected by the University of Iowa plasma wave detector on Voyager 1 starting at 2004.64 and 2006.39, respectively. These interplanetary events have been followed outward from the Sun using plasma and cosmic ray data from Ulysses and Voyagers 1 and 2. For both intervals of kHz emissions, events originating near the Sun that turn out to be the most intense events in this 11-year solar cycle as observed by the plasma and cosmic ray variations in the outer heliosphere, reach V1 and V2 which are near the heliospheric termination shock at almost the same time that the two kHz radio emissions turn-on. These two events which originate near the Sun about 2003.89 (the 2003 Halloween event) and at 2005.71, are also unusual in that they develop solar wind ram pressure waves in the outer heliosphere with maximum pressures ~6-8 times the average solar wind pressure when they reach the heliospheric termination shock. We believe that this study suggests a possible new paradigm for the origin of these latest kHz emissions. This new paradigm is different from the current one describing earlier kHz events. It is related to the strength of these pressure waves in the outer heliosphere and involves the arrival of these large pressure waves at the heliospheric termination shock rather than the arrival of a shock at the heliopause as is the current paradigm., Comment: 12 pages