Nuclei vs Proton: Overview
Me in Nuclei SV (Men's - Women's - read my review).
I have all 5 items:
- Nuclei line: Niche products. Very warm at an instant, incredibly wind resistant and comfortable. But also not breathable at all and come with fragile outer fabrics.
- Nuclei (aka FL): Lesser warm Nuclei.
- Nuclei SV: Warmest Nuclei.
- Proton line: Versatile all round items. Very breathable and durable. But not that warm or wind resistant.
- Proton Lightweight (aka FL): Least warm Proton.
- Proton (aka LT): Mid warm Proton.
- Proton Heavyweight: Warmest Proton.
I love them all. As long as you know what you're getting, none of them will disappoint.
Find comparisons at arcteryx.com below.
- Nuclei (aka FL) vs Proton Lw (aka FL) vs Proton (aka LT):
- Nuclei SV vs Proton Hw:
First thing to note is that Nuclei are more niche products.
They're belay jackets, meaning that they're meant to be put on when you stop moving (whatever high output activity you're performing).
They're meant to get them out of the bag and put them on quick to maintain your core temp.
That's their main purpose. That's why they come with stuff sacks, offer terrible breathability, come with fragile face fabrics that cannot resist abrasion and are cut looser.
From top to bottom: Proton Lw (aka FL), Proton (aka LT), Proton Hw, Nuclei (aka FL) and Nuclei SV.
They are however also spectacularly warm, incredibly wind resistant and extremely comfortable with a bunch of pockets. Its outstanding warmth to weight ratio is mind blowing.
You feel the warmth inside a Nuclei at such an instant that it's insane. Unlike Proton, you don't even need to wait for the warmth to pick up.
This is why I look at Nuclei as down jackets that can get wet. I use them casually as well, as long as my output is none to low.
Luckily, the SV (the warmer) does come with a two way zipper. I primarily use this for comfort reasons when sitting down or driving (keeping only the upper half zipped).
Other use of two way zipper is for dumping excessive heat. Although it's not as effective as the Atom's side fleece panels it still helps a lot.
Proton, on the other hand, are far more versatile. They're perfect for any high output activity, including climbing and heavy backpack use where lots of abrasion is expected.
Their cutting edge face fabrics are much more developed than Nuclei. They're breathable, come with a trimmer cut and shorter hem length.
They're durable and can better resist against abrasion. You can wear them during high output activities or casually.
But even the warmest Proton, Proton Hw, isn't nearly as warm as the warmest Nuclei, Nuclei SV. On top of that, you've got to wait for it to heat you.
Although Proton and Nuclei are both water resistant, when it comes to wind resistance, the Nuclei has the edge by far.
If you rarely get jackets, you might want to get one of the Protons. If warmth and weather resistance are your only concerns, and you don't care about breathability at all, get a Nuclei.
If you're looking for maximizing the breathability, then you should stop reading here and visit Arc'teryx Proton vs Atom guide instead. I've got all the most recent Atoms, too (Hw (aka AR), base (aka LT) and SL (soon to be Lw)) and they're the most breathable line.
Find comparisons at arcteryx.com below.
Nuclei (aka FL) vs Proton Lw (aka FL) vs Proton (aka LT):
- Poll results: Giant Arc'teryx & Patagoina survey (Gore-Tex, pockets, hoods, fit, & more) [1000+ participated]
- Pics from outrageous discounts I ran into at Arc'teryx Parndorf Outlet
- I bought Gamma Lightweight (aka SL), Gamma (aka LT) and Gamma MX
- Patera Parka (one year update): Ain't worth the price...
- Alpha vs Beta: I bought all 4 Beta's and both Alpha's. Settling this for good
- Proton Hybrid: A "hidden" way to stuff it in itself!?
- Best Insulated Jackets: A hands-on Arc'teryx & Patagonia face-off
- 2024 Nano Air is in! Bought it immediately...
- I bought all 7 of Winter '24 Atom and Proton jackets
- Best Arc'teryx Ski Jackets: Rush is ideal, Sabre SV is overkill
- Arc’teryx colors: Most and least liked (poll results)
- Took my Nuclei SV to the Alps near Pfander, Austria
- Arc'teryx Alpha Parka Review: The most impressive jacket of all time
- Arc'teryx ReGEAR: OutdoorCrunch exclusive promo code!
- Beta Insulated Jacket is in: Pit zips AND two way zipper
- DropHood vs StormHood: Pros/cons and best uses
- 7 things all Arc'teryx newbies should know
Naming changes
After changing the names of some women's jackets last season (Fall/Winter 2023), this season Arc'teryx moved on to make the same changes for men's counterparts as well.
- Nuclei FL → Nuclei
- Proton FL → Proton Lightweight (in short, Lw)
- Proton LT → Proton
- There's also a new arrival, Proton Heavyweight.
Changes are exclusive to the naming and fit. Structural designs remain the same. The fit is being updated universally, for all Arc'teryx jackets.
Canberk is 5'11" and 165 pounds, with an athletic build. Size Medium fits him perfectly across almost all brands and product lines. 
Nuclei vs Proton: Warmth
Check out the table below.
You'll see not one but two different insulation thicknesses for Nuclei SV.
- Two layers of Coreloft (180 gsm) takes place at the front, back, and upper arms.
- Single layer of Coreloft (90 gsm) takes place at underarms, lower arm, sides, and hood.
Name Activity Temp (F/C) Breathability Weather Res. Durability Bottom line Review Pit zips? Two way zipper? Stuffs into itself? Face Fabric Fit Weight Length Alpha (aka AR) (Men's - Women's) Climbing N/A 8/10 9/10 8/10 4/10 Go-to climbing harshell. Review Yes No No N40d & N80d Most Rugged 3L Gore-Tex Pro Regular 430 g / 15.2 oz 79.5 cm / 31.25 in No Alpha FL (Men's - Women's) Climbing N/A 7/10 No data No data 10/10 No No Yes Hadron 3L Gore-Tex Trim 209 g / 7.4 oz 76.5 cm / 30 in Yes Alpha IS (Men's) Climbing 23/-5 7/10 5/10 No data 8/10 No Yes Yes N40p-X 2L Gore-Tex Regular 610 g / 1 lb 5.5 oz 78 cm / 30.75 in Yes Alpha SL (Men's - Women's) Climbing N/A 5/10 7/10 No data 9/10 No No Yes N40p 3L Gore-Tex Trim 326 g / 11.5 oz 77.5 cm / 30.5 in Yes Alpha SV (Men's - Women's) Climbing N/A 8/10 10/10 10/10 3/10 Strongest climbing hardshell. Review Yes No No N100d Most Rugged 3L Gore-Tex Pro Regular 510 g / 1 lb 2 oz 78 cm / 30.75 in No Andessa (Women's) Skiing 8/-13 10/10 No data No data 1/10 Yes No No N40d 3L Gore-Tex Trim 869 g / 1 lb 14.7 oz 67 cm / 26.4 in Yes Andessa Shell (Women's) Skiing N/A 5/10 No data No data 3/10 No No No N70p 3L Gore-Tex Trim 560 g / 1 lb 3.8 oz ? Yes Beta (Men's - Women's) All Round N/A 6/10 7/10 7/10 8/10 Streamlined all-doer shell. Review No No No N30p-X 3L Gore-Tex Trim 300 g / 10.6 oz 76 cm / 30 in No Beta AR (Men's - Women's) All Round N/A 8/10 9/10 9/10 4/10 Go-to all-round harshell. Review Yes No No N40d & N80d Most Rugged 3L Gore-Tex Pro Regular 460 g / 1 lb 76 cm / 30 in No Beta AR StormHood (Men's - Women's) All Round N/A 8/10 9/10 9/10 4/10 Review Yes No No N40d & N80d Most Rugged 3L Gore-Tex Pro Regular 460 g / 1 lb 76 cm / 30 in No Beta Coat (Women's) All Round N/A 6/10 5/10 No data 5/10 No Yes No 3L Gore-Tex Regular 320 g / 11.3 oz 88 cm / 34.5 in No Beta Down Insulated (Men's) All Round 0/-18 9/10 7/10 8/10 No data Yes Yes No 2L 40D Gore-Tex Regular 760 g / 1 lb 10.8 oz 79 cm / 31 in No Beta Insulated (Men's - Women's) All Round 21/-6 9/10 7/10 8/10 No data Go-to hybrid jacket. Review Yes Yes No N40d 2L Gore-Tex Regular 680 g / 1 lb 8 oz 78.5 cm / 31 in No Beta Insulated Coat (Women's) All Round 16/-9 7/10 No data No data No data No Yes No N40d 2L Gore-Tex Regular 600 g / 1 lb 5.2 oz 86 cm / 34 in No Beta Lightweight (Men's - Women's) All Round N/A 8/10 7/10 7/10 6/10 Review Yes No No N40p 3L Gore-Tex Fitted 380 g / 13.4 oz 75 cm / 29.5 in No Beta Long All Round N/A 4/10 9/10 No data 3/10 Review No No No N80p 3L Gore-Tex Regular 441 g / 15.6 oz 85 cm / 33.5 in Yes Beta LT (Men's - Women's) All Round N/A 7/10 7/10 8/10 6/10 Review Yes No No N40d 3L Gore-Tex Fitted 395 g / 13.9 oz 76 cm / 30 in No Beta LT Hadron All Round N/A 7/10 6/10 4/10 5/10 No No No Hadron 3L Gore-Tex Fitted 255 g / 9 oz 76 cm / 30 in Yes Beta SV (Men's - Women's) All Round N/A 8/10 10/10 10/10 3/10 Strongest all-round harshell. Review Yes No No N80p-X Most Rugged 3L Gore-Tex Pro Regular 495 g / 1 lb 1.5 oz 79 cm / 31 in Yes Cassiar (Men's) Skiing N/A 8/10 7/10 8/10 3/10 Review Yes No No N70p 3L Gore-Tex Trim 820 g / 1 lb 12.9 oz 74.5 cm / 29.3 in Yes Cassiar LT (Men's) Skiing N/A 6/10 6/10 6/10 5/10 Review Yes No No N70p 3L Gore-Tex Trim 605 g / 1 lb 5.3 oz 75 cm / 29.5 in Yes Cita (Women's) Running N/A 7/10 4/10 5/10 10/10 Review No No Yes Lumin Trim 120 g / 4.2 oz 67.5 cm / 26.5 in Yes Cita SL (Women's) Running N/A 7/10 4/10 4/10 10/10 Review Yes No Yes Permeair 20 Trim 65 g / 2.3 oz 61.5 cm / 24.2 in Yes Gamma (aka LT) (Men's - Women's) All Round N/A 7/10 3/10 7/10 3/10 Go-to softshell. Review No No No Wee Burly Double Weave Regular 545 g / 1 lb 3.2 oz 76 cm / 30 in No Gamma SL (aka lightweight) (Men's - Women's) All Round N/A 7/10 2/10 6/10 5/10 Review No No No Fortius 1.0 Trim 310 g / 10.9 oz 74 cm / 29.1 in Yes Gamma MX (Men's) All Round N/A 6/10 4/10 8/10 3/10 Strongest softshell. Review No No No Fortius 2.0 Regular 555 g / 1 lb 3.6 oz 74 cm / 29.1 in No Incendia (Women's) Skiing N/A 8/10 9/10 9/10 3/10 Review Yes No No NP100d 3L Gore-Tex Trim 610 g / 1 lb 5.5 oz 79 cm / 31 in Yes Incendo (Men's) Running N/A 7/10 4/10 5/10 10/10 Review No No Yes Lumin Trim 125 g / 4.4 oz ? Yes Incendo Airshell (Men's Running N/A No data No data No data No data No No Yes ? Trim 105 g / 3.7 oz ? Yes Incendo SL (Men's) Running N/A 7/10 4/10 4/10 10/10 Review No No Yes Permair 20 & Canim Trim 80 g / 2.8 oz 73 cm / 28.75 in Yes Indencia IS Skiing No data No data No data No data No data Yes No No N80p 2L Gore-Tex Regular ? 78 cm / 30.75 in Yes Macai (Men's) Skiing 5/-15 7/10 7/10 6/10 1/10 Review Yes No No N40p-X 3L Gore-Tex Regular 990 g / 2 lb 2.9 oz 75 cm / 29.5 in Yes Macai Lightweight (aka LT) (Men's) Skiing 8/-13 7/10 7/10 6/10 2/10 Review Yes No No N40p-X 3L Gore-Tex Regular 855 g / 1 lb 14.2 oz ? Yes Macai Shell (Men's) Skiing N/A No data No data No data No data Review Yes No No N80p-X 3L Gore-Tex Regular 775 g / 1 lb 11.3 oz ? Yes Micon (Men's) Skiing N/A No data No data No data No data Yes No No N80p 3L Gore-Tex Regular 685 g / 1 lb 8.2 oz 83 cm / 32.5 in Yes Micon Heather Skiing N/A No data No data No data No data Yes No No NP100-d 3L Gore-Tex Regular 685 g / 1 lb 8.2 oz 83 cm / 32.5 in Yes Nodin (Men's - Women's) Running N/A 8/10 5/10 5/10 10/10 No No Yes 20D Tyono Trim 130 g / 4.6 oz 75 cm / 29.5 in Yes Norvan LT (Men's - Women's) Running N/A 5/10 5/10 8/10 6/10 No No No N13p 3L Gore-Tex Trim 190 g / 6.7 oz ? Yes Norvan Shell (Men's Running N/A No data No data No data No data No No No 13D 3L Gore-Tex Trim 190 g / 6.7 oz 73 cm / 28.75 in No Norvan SL (Men's - Women's) Running N/A 7/10 6/10 8/10 8/10 Review No No Yes Gore-Tex Infinium Trim 120 g / 4.2 oz 77 cm / 30.4 in Yes Norvan SL Ins. (Women's) Running 39/4 No data No data No data No data No No Yes Gore-Tex ShakeDry Trim 270 g / 9.5 oz 71.5 cm / 28.1 in Yes Norvan Windshell (Men's Running N/A No data No data No data No data No No Yes Permeair 20 Trim 90 g / 3.2 oz 73 cm / 28.75 in Yes Procline (Men's) Skiing N/A No data No data No data No data Yes No No N70p Gore-Tex Infinium Trim 720 g / 1 lb 9.4 oz 76 cm / 30 in Yes Ravenna (Women's) Skiing N/A 8/10 7/10 8/10 3/10 Review Yes No No N70s-4 3L Gore-Tex Trim 725 g / 1 lb 9.6 oz 69.5 cm / 27.4 in Yes Ravenna LT (Women's) Skiing N/A 6/10 6/10 6/10 5/10 Review Yes No No N70p 3L Gore-Tex Trim 540 g / 1 lb 3 oz 69 cm / 27.2 in Yes Rush (Women's) Skiing N/A 8/10 9/10 9/10 3/10 Go-to ski jacket. Review Yes No No N80p-X & N100p-X 3L Most Rugged Gore-Tex Pro Regular 590 g / 1 lb 4.8 oz 79.5 cm / 31.25 in No Rush (Women's) Skiing 16/-9 3/10 5/10 5/10 9/10 Review No No Yes Hadron 2L Gore-Tex Infinium Regular 515 g / 1 lb 2.2 oz 79 cm / 31 in No Sabre (Men's) Skiing N/A 8/10 8/10 7/10 2/10 Review Yes No No N80p-X 3L Gore-Tex Regular 705 g / 1 lb 8.9 oz 79 cm / 31 in No Sabre AR (Men's) Skiing N/A 7/10 8/10 7/10 7/10 Review Yes No No N70p 3L Gore-Tex Regular 700 g / 1 lb 8.7 oz 79 cm / 31 in Yes Sabre Insulated (See related products) Skiing No data 7/10 No data 6/10 No data Review Yes No No N80p 2L Gore-Tex Regular 815 g / 1 lb 12.7 oz 76 cm / 30 in Yes Sabre LT (Men's) Skiing N/A 7/10 8/10 7/10 8/10 Review Yes No No N80p 3L Gore-Tex Regular 660 g / 1 lb 7.3 oz 83 cm / 32.5 in Yes Sabre SV (Men's) Skiing N/A 10/10 10/10 10/10 1/10 Strongest ski jacket. Review Yes Yes No N100d Most Rugged 3L Gore-Tex Pro Regular 595 g / 1 lb 5 oz 85 cm / 33.5 in Yes Sentinel (Women's) Skiing N/A 8/10 7/10 7/10 2/10 Go-to ski jacket. Review Yes No No N70p 3L Gore-Tex Regular 640 g / 1 lb 6.6 oz 73.7 cm / 29 in No Sentinel AR (Women's) Skiing N/A 7/10 8/10 7/10 7/10 Review Yes No No N70p 3L Gore-Tex Regular 590 g / 1 lb 4.8 oz 72.5 cm / 28.5 in Yes Sentinel Insulated (Women's) Skiing 21/-6 8/10 No data No data No data Review Yes No No N80p 2L Gore-Tex Regular 600 g / 1 lb 5.2 oz 79.8 cm / 31.5 in No Sentinel LT (Women's) Skiing N/A 7/10 8/10 7/10 8/10 Review Yes No No N80p 3L Gore-Tex Regular 565 g / 1 lb 3.9 oz 73.5 cm / 29 in Yes Sentinel Relaxed (Women's) Skiing N/A No data No data No data No data Yes No No N80p 3L Gore-Tex Regular 655 g / 1 lb 7.1 oz ? No Shashka Stretch (Women's) Skiing N/A No data No data No data No data Yes No No N70p Gore-Tex Infinium Trim 670 g / 1 lb 7.6 oz 71 cm / 28 in Yes Sidewinder (Women's) Skiing N/A 8/10 8/10 7/10 2/10 Yes No No N80p 3L Gore-Tex Regular 570 g / 1 lb 4.1 oz ? No Solano (Men's - Women's) Around Town N/A No data No data No data No data Review No No No Gore-Tex Infinium Relaxed 355 g / 12.5 oz 72 cm / 28.3 in No Squamish (Men's - Women's) Running N/A 5/10 4/10 7/10 9/10 Go-to running jacket. Review No No Yes 30D Tyono Trim 140 g / 4.9 oz 77.5 cm / 30.5 in No Theriss Down (Women's) Skiing No data 7/10 6/10 7/10 2/10 Review Yes No No N80p 2L Gore-Tex Regular 709 g / 1 lb 9 oz 63 cm / 24.8 in No Trino SL (Men's) Running N/A 8/10 5/10 7/10 6/10 Review No No No Gore-Tex Infinium Trim 340 g / 12 oz 74 cm / 29.1 in Yes Trino SL Anorak (Women's) Running N/A 8/10 7/10 8/10 7/10 Review No No No Gore-Tex Infinium Trim 290 g / 10.2 oz 65 cm / 25.5 in Yes Venda Anorak (Women's) Around Town N/A No data No data No data No data No No No Gore-Tex Relaxed 255 g / 9 oz 75.5 cm / 29.7 in Yes Zeta AR (Men's) Hiking N/A 7/10 8/10 7/10 4/10 Yes No No 3L Gore-Tex Regular 425 g / 15 oz 80 cm / 31.5 in Yes Zeta FL (Men's - Women's) Hiking N/A 4/10 6/10 4/10 6/10 No No No N20r 2L Gore-Tex Trim 221 g / 7.8 oz 76 cm / 30 in Yes Zeta LT (Men's - Women's) Hiking N/A 5/10 7/10 8/10 5/10 No No No N40P-X 3L Gore-Tex Trim 335 g / 11.8 oz 78 cm / 30.75 in Yes Zeta SL (Men's - Women's) Hiking N/A 3/10 5/10 4/10 5/10 Review No No No 2L Gore-Tex Trim 310 g / 10.9 oz 77.8 cm / 30.6 in Yes
Performance data axis of synthetic jackets (table above) and shell jackets (this table) are different. Don't compare them.
Nuclei vs Proton: Packability
Unfortunately, none of the Protons offer packability.
Both Nuclei come with attached stuff sacks.
Both Nuclei come with an attached stuff sack. They take place inside the dump pocket when not in use. Image belongs to Nuclei SV.
Nuclei SV is packed larger.
- Packed sizes:
- Nuclei SV: 11 in (or 28 cm) length x 7.1 in (or 18 cm) diameter
- Nuclei (aka FL): 10.2 in (or 26 cm) length x 5.1 in (or 13 cm) diameter
See images below.
Both offer a reinforced loop when packed (see packed sizes image).
Nuclei vs Proton: Pockets
Let's start with Protons.
- Proton Hw:
- Hand warmers: 9.1 in (or 23 cm) x 8.3 in (or 21 cm)
- Internal dump pockets: 7.9 in (or 20 cm) x 8.3 in (or 21 cm)
- External chest pockets: See image.
- Proton:
- Hand warmers: 9.4 in (or 24 cm) height x 7.5 in (or 19 cm) width
- External chest pocket: See image.
- Proton Lw:
- Hand warmers: 10.26 inches (or 26 cm) height x 7.1 inches (18 cm) width
- External chest pocket: See image.
Proton and Proton Lw offers 1, Proton Hw offers 2 chest pockets.
- Nuclei SV:
- Hand warmers: 11.8 in (or 30 cm) x 7.5 in (or 19 cm)
- External zippered chest pocket: 11 in (or 28 cm) x 8.3 in (or 21 cm)
- Dump pockets: 7.5 in (or 19 cm) x 10.2 in (or 26 cm)
- Nuclei (aka FL):
- Hand warmers: 7.5 in (or 19 cm) x 7.9 in (or 20 cm)
- Dump pockets: 7.5 in (or 19 cm) x 8.7 in (or 22 cm)
Nuclei vs Proton: Cuffs
Nuclei FL is different than the other four. One is not better than the other, it's simply up to you.
Left: Nuclei (aka FL). Right: Nuclei SV.
Poll results: Best colorways of Proton Series
Upvote your favorites.
Solace
Phenom
Black
Solitude
Lucent Multiverse
Phenom Bordeaux
Black
Serene
Black
Atmos
Sprint
Moonlit
Labyrinth
Black
Phenom
Quick links:
Find comparisons at arcteryx.com below.
Nuclei (aka FL) vs Proton Lw (aka FL) vs Proton (aka LT):
Best colors
Poll results: Best colorways of Proton Series
Upvote your favorites.
Solace
Phenom
Black
Solitude
Lucent Multiverse
Phenom Bordeaux
Black
Serene
Black
Atmos
Sprint
Moonlit
Labyrinth
Black
Phenom
Quick links:
Check out our other content on jackets:
Guide: Insulated & Shell Jackets
Start here:
Also see:
Canberk: Coming late to this post. As always your thoughts and experiences with the gear are pretty spot on. Many thanks! Teshekher ederum!
I personally use the Proton LT Hoody for my mountain-biking/higher exertion efforts and always carry a Squamish (Arc) or Houdini (Patagonia) windshell (easily pack-able, light weight, etc.) in case the winds come up.
Of course, living in Colorado, USA the chances of heavy rain are pretty unlikely, so I literally have no Goretex outer layers. That would change quickly if I were to travel to other climes.
Keep up the great work and stay healthy, safe, and sane!! 🙂
Hi! Do you think that proton lt and nuclei fl would layer well together? Wearing more windproof nuclei over breathable proton when (for example) having a little break in cold, windy conditions sounds perfect to me, but I’m not sure if nuclei has enough room for proton lt under and would it be comfortable to wear them both at once (I know I can size up but let’s suppose they are in same size) :))
Have you changed your warmth rating form the last season? I see that now Cerium LT and Nuclei FL went up by something like 7 degrees celsius in terms of lowest comfortable limit. Why?
BTW: I really appreciate your site and find it really useful.