example solar proton event data - emmrem.unh.edu

M. Kim and F. Cucinotta

Example Solar Proton Event Data

NASA JSCAugust 30, 2006


Times of Occurrence of Large SPE’s

GCR Deceleration Potential

200

400

600

800

1000

1200

1400

1600

1800

1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 2015 2020Year

Φ, M

V

+ + + +- - -

1/1/1950 1/1/1960 1/1/1970 1/1/1980 1/1/1990 1/1/2000 1/1/2010 1/1/2020

F(>3

0 M

eV),

Pro

tons

/cm

2

108

109

1010F>108 solar protonevents only

Recent Era (1550-2000)McKracken et al.Modern Era (1956-2005)


Projections of Cycles and Mean Occurrence Frequency of SPE

0

20

40

60

80

100

120

140

160

180

200

1996 2001 2006 2011 2016

Year

Suns

pot n

umbe

r

0

2

4

6

8

10

12

14

< ν(t

)>, E

vent

s/ye

ar

Population distribution level, percent90

70

50

30

10

Measured sunspot number

Smoothed sunspot number

Projected smoothedsunspot number at level, percent

807570

Cycle 23 Cycle 24

<ν(t)> :Φ30>=105

Φ30>=106


Cycle Onset Time Φ30, protons/cm2 Time to Peak Flux, hr Comment19 11/12/1960 9.00 x 109 14 (a), note 120 8/2/1972 5.00 x 109 69 (a)22 10/19/1989 13:05 4.23 x 109 26.9 (b)

23 7/14/2000 10:45 3.74 x 109 25.8 (b)

23 10/26/2003 18:25 3.25 x 109 4.2 (b), note 223 11/4/2001 17:05 2.92 x 109 33.2 (b)

19 7/10/1959 2.30 x 109 note 3 (a)

23 11/8/2000 23:50 2.27 x 109 16.1 (b)

22 3/23/1991 8:20 1.74 x 109 19.5 (b)

22 8/12/1989 16:00 1.51 x 109 15.2 (b)

22 9/29/1989 12:05 1.35 x 109 14.1 (b)

23 1/16/2005 2:10 1.04 x 109 39.7 (b)19 2/23/1956 1.00 x 109 note 4 (a)

Large Solar Proton Events during Solar Cycles 19-23 with Φ30 > 109 protons/cm2

(a) Φ30 for solar cycle 19-21: data taken from Shea and Smart.(b) Φ30 for solar cycle 22 and 23: calculated using corrected 5-min average proton flux of GOES measurements.Note 1: There are large differences in the estimate of fluence in November 1960 SPE.

Data given by others are significantly smaller than this value (1.3 x 109 protons/cm2 by Freier and Webber).Note 2: Φ30 for the combined 3 major peaks occurred during 10/26-11/6/2003: 3.42 x 109 protons/cm2.Note 3: one day later on July 11, 1959 Note 4: in the same day on February 23, 1956


Proton Integral FluxAugust 2-11, 1972 SPE

10

100

1,000

10,000

100,000

1,000,000

0 50 100 150 200 250

Time, h

Flux

, Pro

tons

/cm

2 -s

E > 10 MeV

E > 30 MeV

E > 60 MeV


BFO Dose RateAugust 2-11, 1972 SPE

1.E-05

1.E-04

1.E-03

1.E-02

1.E-01

1.E+00

1.E+01

1.E+02

0 40 80 120 160 200 240

Time, hr

Dos

e R

ate,

cG

y-Eq

/h

AL(0)AL(1)AL(3)AL(5)AL(10)AL(15)AL(20)AL(30)1 cGy/h


BFO Cumulative DoseAugust 2-11, 1972 SPE

1.E-03

1.E-02

1.E-01

1.E+00

1.E+01

1.E+02

1.E+03

0 40 80 120 160 200 240

Time, h

Cum

ulat

ive

Dos

e Eq

uiva

lent

, cSv Current 30-day limit

Al thickness, g/cm2:0135

10152030


82 BFO Locations

● 32 location set● 50 location set


August 1972 SPE (1 g/cm2 Al shield)

BFO Location0 5 10 15 20 25 30 35 40 45 50

BFO

Dos

e E

q, c

Gy-

Eq

0

100

200

300

400

500

Marrow location, jHead and NeckUpper TorsoMiddle TorsoThighsAverage


Hourly-Averaged Proton Integral Flux during Oct 26 - Nov 6, 2003 SPE

0.1

1

10

100

1000

10000

100000

0 50 100 150 200 250 300

Time, h

Flux

, pro

tons

/cm

2 -s

E ≥ 30 MeVE ≥ 60 MeVE ≥ 100 MeV


0.000001

0.00001

0.0001

0.001

0.01

0.1

1

10

0 50 100 150 200 250 300

Time, h

Dos

e R

ate,

cSv

/h

1 rem/h

Al thickness,g/cm2:

0135

10152030

BFO Dose Rate during Oct 26 - Nov 6, 2003 SPE


0.1

1

10

100

1000

10000

100000

0 50 100 150 200 250 300

Time, h

Flux

, pro

tons

/cm

2 -s

E ≥ 30 MeVE ≥ 60 MeVE ≥ 100 MeV

Hourly-Averaged Proton Integral FluxOct 26 - Nov 6, 2003 SPE


BFO Dose RateOctober 26- November 6, 2003 SPE

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

10

0 50 100 150 200 250 300Time, h

Dos

e R

ate,

cG

y-Eq

/h

1 cGy/h

Al thickness,g/cm2:

0135

10152030


BFO Cumulative DoseOctober 26- November 6, 2003 SPE

1.E-05

1.E-04

1.E-03

1.E-02

1.E-01

1.E+00

1.E+01

1.E+02

0 50 100 150 200 250 300Time, h

Cum

ulat

ive

Dos

e Eq

uiva

lent

, cSv

AL(0)AL(1)AL(3)AL(5)AL(10)AL(15)AL(20)AL(30)

Current 30-day limit


1.E-01

1.E+00

1.E+01

1.E+02

1.E+03

1.E+04

1.E+05

0 20 40 60 80 100 120 140 160 180

Time, h

Flux

, pro

tons

/cm

2 -s

E ≥ 10 MeVE ≥ 30 MeVE ≥ 60 MeVE > 100 MeV

Hourly-Averaged Proton Integral FluxJanuary 16-22, 2005 SPE


BFO Dose RateJanuary 16-22, 2005 SPE

1.E-05

1.E-04

1.E-03

1.E-02

1.E-01

1.E+00

1.E+01

0 20 40 60 80 100 120 140 160 180

Time, h

Dos

e R

ate,

cG

y-Eq

/h

1 cGy/h

Al thickness, g/cm2

0 1 3 5

10 15 20 30


1.E-05

1.E-04

1.E-03

1.E-02

1.E-01

1.E+00

1.E+01

1.E+02

0 20 40 60 80 100 120 140 160 180

Time, h

Cum

ulat

ive

Dos

e Eq

uiva

lent

, cSv

AL(0)AL(1)AL(3)AL(5)AL(10)AL(15)AL(20)AL(30)

Current 30-day limit

BFO Cumulative DoseJanuary 16-22, 2005 SPE


Role of Dose-Rate and ShieldingShielding mitigates most SPE events

High-energy component (>100 MeV) often poorly knownProton biological damage is dependent on dose-rate

Effects increase above ~5 rad/hr

EVA Today (Y/N?)IVA (time to storm shelter)


216 Particle Events (1976-2005)

0

5

10

15

20

250

1.5 3

4.5 6

7.5 9

10.5 12

13.5 15

16.5 18

19.5 21

22.5 24

25.5 27

28.5 30

31.5 33

34.5 36

37.5 39

40.5 42

43.5 45

46.5

Time to Max Proton Flux, hr

Freq

uenc

y

.00%

10.00%

20.00%

30.00%

40.00%

50.00%

60.00%

70.00%

80.00%

90.00%

100.00%

FrequencyCumulative %


Large SPE Integral Fluence Spectra at 1AU

1.E+04

1.E+05

1.E+06

1.E+07

1.E+08

1.E+09

1.E+10

1.E+11

1.E+12

1 10 100 1000

Kinetic energy, MeV

Φp(

>E),

prot

ons/

cm2

Feb 1956 SPE

Aug 1972 SPE

Nov 1960 SPE

Oct 2003 SPE


Big SPEs (Cycles 22-23)

1.00E-08

1.00E-06

1.00E-04

1.00E-02

1.00E+00

1.00E+02

1.00E+04

1.00E+06

1.00E+08

1.00E+10

1.00E+12

1 10 100 1000

E, MeV/amu

Φ (>

E), c

m-2

10/19/1989 SPE7/14/2000 SPE9/29/1989 SPE11/8/2000 SPE10/26/2003 SPE11/4/2001 SPE1/16/2005 SPE8/12/1989 SPE10/30/1992 SPE6/4/1991 SPE9/24/2001 SPE11/6/1997 SPE6/14/1991 SPE3/23/1991 SPE4/21/2002 SPE11/2/2003 SPE11/22/2001 SPE4/20/1998 SPE11/30/1989 SPE


From Nymik- COSPAR


The Average BFO Doses of the Regions at 6 DLOCs from 1972 SPE

0

20

40

60

80

100

120

140

DLOC1 DLOC2 DLOC3 DLOC4 DLOC5 DLOC6

BFO

Dos

e, c

Gy-

Eq

Head & NeckChestAbdomenPelvisThighsLower LegsArms


Was Carrington Event (1859) Lethal?1859 event has largest F>30 Flux known

Proton Fluence >30 MeV per cm2

108 109 1010

% P

roba

bilit

y in

2-W

eek

Mis

sion

s

0.001

0.01

0.1

1

10

100

Blood Forming Organ Dose, cGy-Eq1 10 100

30-d

ay D

ose

Lim

it Vi

olat

ion

5% P

rodr

omal

Si

ckne

ss Mission disruption-days lost?

Increased fatal cancer riskand other late effects

Modern data(1956-2005)

Arctic ice-core data

5% A

cute

Let

halit

y U

nifo

rm D

ose

Single Mission

3 missions/year for5-yr Program

Conditions underApollo Spacecraft -type shielding

Ice-Core data-F>30MeV flux from1450-1990


Large SPE’s


Long-Term ForecastingClimax Neutron Monitor and Deceleration Potential (Φ)

1900

2400

2900

3400

3900

4400

1953 1963 1973 1983 1993 2003 2013

Time

Clim

ax C

osm

ic R

ay M

onth

ly M

eans

400

900

1400

1900

2400

2900

, MV

Measured ClimaxNMEstimated Cli(DR75%)PHI(T)3-month Ave PHI(T)


SPE Probability in 1-Week Missionand

BFO Exposure Level inside a Typical Equipment Room in Free Space

1.E-05

1.E-04

1.E-03

1.E-02

1.E-01

1.E+00

1.E+03 1.E+04 1.E+05 1.E+06 1.E+07 1.E+08 1.E+09 1.E+10 1.E+11

Size of Event (>Φ30)

SPE/

Mis

sion

0.1

1

10

100

1000

BFO

Dos

e, c

Gy-

Eq Average Probability of Space Era Extended Average ProbabilityImpulsive Nitrate EventsBFO Dose of Worst Case SPE ModelBFO Dose of SPE during Space Era

NCRP 30-day limit at BFO for LEO mission


Frequency of SPE Occurrence in 3-Month PeriodsΦ30 > 108 protons/cm2 for Solar Cycle 21.

0

1

2

3

4

5

6

7

8

3 12 21 30 39 48 57 66 75 84 93 102

111

120

Time from Solar Minimum, month

Freq

uenc

y

0

50

100

150

200

Smoo

thed

Mon

thly

Sun

spot

Num

ber

FrequencyMonthly sunspot number

Feb 1978

Apr 1978

Sept 1978Sept 1979

Apr 1981

Jan 1982

Oct 1981

Dec 1982

Apr 1984



0

1

2

3

4

5

6

7

8

3 12 21 30 39 48 57 66 75 84 93 102

111

120


Freq

uenc

y

0

50

100

150

200

Smoo

thed

Mon

thly

Sun

spot

Num

ber


Sept 1989Oct 1989Aug 1989

Mar 1991



0

1

2

3

4

5

6

7

8

3 12 21 30 39 48 57 66 75 84 93 102

111

120


Freq

uenc

y

0

50

100

150

200

Smoo

thed

Mon

thly

Sun

spot

Num

ber


Jul 2000

Nov 2000

Nov 2001

Oct 2003

Jan 2005


GCR and SPE Dose: Materials & TissueGCR higher energy >> secondary radiation

With Tissue ShieldingNo Tissue Shielding

Shielding Depth, g/cm2

0 5 10 15 20 25 30 35

Dos

e E

quiv

alen

t, cS

v/yr

1

10

100

1000

10000

GCR HydrogenGCR PolyethyleneGCR GraphiteGCR AluminumGCR RegolithSPE GraphiteSPE Regolith

Shielding Depth, g/cm2

0 5 10 15 20 25 30 35

Dos

e E

quiv

alen

t, cS

v/yr

1

10

100

1000

GCR HydrogenGCR PolyethyleneGCR GraphiteGCR AluminumGCR RegolithSPE GraphiteSPE RegolithSPE Hydrogen


Risk and Uncertainties increase with Linear Energy Transfer (LET)

LET, keV/µm1 10 100 1000

REI

D(%

) 0

1

2

3

4

5

6

7

8

Fold uncertainty

Dose = 0.01 Gy

TEPC Data on NASA-MIR 7 (1/21/1998 to 5/28/1998)

y (~LET), keV/µm0.1 1 10 100 1000

F(>y

), (d

ay c

m2 )-1

0.01

0.1

1

10

100

1000

10000

GCRTrappedTotal

95% CL of Risk Model

Dose = Flux x LETBiological Dose H = Dose X Q(L)REID = Risk of exposure induced death = H x R0(sex,age)


Accuracy of Space Radiation Transport Models


Model vs. Phantom Expt. (STS and ISS)

ISS Increment-2results


Phantom Torso TEPC Trapped + GCR Differential FluxJune 25 - July 3, 2001

Lineal Energy (Tissue, keV/µm)

10-1 100 101 102 103 104

Diff

eren

tial F

lux,

Num

ber/c

m2 s

r day

keV

/µm

10-5

10-4

10-3

10-2

10-1

100

101

102

103

104

105


NASA-MIR 7 (1/21/1998 to 5/28/1998)

y, keV/µm0.1 1 10 100 1000

F(>y

), (d

ay c

m2 )-1

0.01

0.1

1

10

100

1000

10000

GCRTrappedTotal


1.E-05

1.E-03

1.E-01

1.E+01

1.E+03

1.E+05

1.E+07

0.01 0.1 1 10 100 1000

0" (x100)

5" (x10)

7" (x1)

9" (x0.1)

1.E-05

1.E-03

1.E-01

1.E+01

1.E+03

1.E+05

1.E+07

0.01 0.1 1 10 100 1000

0" (x100)

5" (x10)

7" (x1)

9" (x0.1)

LET vs TEPC

TEPC model Vs TEPC (no TF)

example solar proton event data - emmrem.unh.edu

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