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Title: Producing KDP and DKDP crystals for the NIF laser

Abstract

The cost and physics requirements of the NIF have established two important roles for potassium dihydrogen phosphate (KDP) crystals. 1. To extract more laser energy per unit of flashlamp light and laser glass, the NIF has adopted a multipass architecture as shown in Figure 1. Light is injected in the transport spatial filter, first traverses the power amplifiers, and then is directed to main amplifiers, where it makes four passes before being redirected through the power amplifiers towards the target. To enable the multipass of the main amplifiers, a KDP-containing Pockels cell rotates the polarization of the beam to make it either transmit through or reflect off a polarizer held at Brewster's angle within the main laser cavity. If transmitted, the light reflects off a mirror and makes another pass through the cavity. If reflected, it proceeds through the power amplifier to the target. the original seed crystal as the pyramid faces grow. Unfortunately, this pyramidal growth is very slow, and it takes about two years to grow a crystal to NIF size. To provide more programmatic flexibility and reduce costs in the long run, we have developed an alternative technology commonly called rapid growth. Through a combination of highermore » temperatures and higher supersaturation of the growth solution, a NIF-size boule can be grown in 1 to 2 months from a small ''point'' seed. However, growing boules of adequate size is not sufficient. Care must be taken to prevent inclusions of growth solution and incorporation of atomically substituted 2. Implosions for ICF work far better at shorter wavelengths due to less generation of hot electrons, which preheat the fuel and make it harder to compress. Compromising between optic lifetime and implosion efficiency, both Nova and the NIF operate at a tripled frequency of the 1053-nm fundamental frequency of a neodymium glass laser. This tripling is accomplished by two crystals, one made of KDP and one made of deuterated KDP (DKDP). The first one mixes two 1053-nm photons to make 526-nm light, and the second one combines a residual 1053-nm photon with a 526-nm photon to make 351-nm light.« less

Authors:
; ; ; ; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Lawrence Livermore National Lab., CA (US)
Sponsoring Org.:
USDOE Office of Defense Programs (DP) (US)
OSTI Identifier:
14145
Report Number(s):
UCRL-ID-135590; 39DP02000
39DP02000; TRN: US0110970
DOE Contract Number:  
W-7405-ENG-48
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: 2 Sep 1999
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; 36 MATERIALS SCIENCE; AMPLIFIERS; LASERS; POTASSIUM PHOSPHATES; POWER AMPLIFIERS; US NATIONAL IGNITION FACILITY; LASER MATERIALS; DEUTERIUM COMPOUNDS

Citation Formats

Atherton, L J, Burnham, A K, Combs, R C, Couture, S A, De Yoreo, J J, Hawley-Fedder, R A, Montesant, R C, Robey, H F, Runkel, M, Staggs, M, Wegner, P J, Yan, M, and Zaitseva, N P. Producing KDP and DKDP crystals for the NIF laser. United States: N. p., 1999. Web. doi:10.2172/14145.
Atherton, L J, Burnham, A K, Combs, R C, Couture, S A, De Yoreo, J J, Hawley-Fedder, R A, Montesant, R C, Robey, H F, Runkel, M, Staggs, M, Wegner, P J, Yan, M, & Zaitseva, N P. Producing KDP and DKDP crystals for the NIF laser. United States. doi:10.2172/14145.
Atherton, L J, Burnham, A K, Combs, R C, Couture, S A, De Yoreo, J J, Hawley-Fedder, R A, Montesant, R C, Robey, H F, Runkel, M, Staggs, M, Wegner, P J, Yan, M, and Zaitseva, N P. Thu . "Producing KDP and DKDP crystals for the NIF laser". United States. doi:10.2172/14145. https://www.osti.gov/servlets/purl/14145.
@article{osti_14145,
title = {Producing KDP and DKDP crystals for the NIF laser},
author = {Atherton, L J and Burnham, A K and Combs, R C and Couture, S A and De Yoreo, J J and Hawley-Fedder, R A and Montesant, R C and Robey, H F and Runkel, M and Staggs, M and Wegner, P J and Yan, M and Zaitseva, N P},
abstractNote = {The cost and physics requirements of the NIF have established two important roles for potassium dihydrogen phosphate (KDP) crystals. 1. To extract more laser energy per unit of flashlamp light and laser glass, the NIF has adopted a multipass architecture as shown in Figure 1. Light is injected in the transport spatial filter, first traverses the power amplifiers, and then is directed to main amplifiers, where it makes four passes before being redirected through the power amplifiers towards the target. To enable the multipass of the main amplifiers, a KDP-containing Pockels cell rotates the polarization of the beam to make it either transmit through or reflect off a polarizer held at Brewster's angle within the main laser cavity. If transmitted, the light reflects off a mirror and makes another pass through the cavity. If reflected, it proceeds through the power amplifier to the target. the original seed crystal as the pyramid faces grow. Unfortunately, this pyramidal growth is very slow, and it takes about two years to grow a crystal to NIF size. To provide more programmatic flexibility and reduce costs in the long run, we have developed an alternative technology commonly called rapid growth. Through a combination of higher temperatures and higher supersaturation of the growth solution, a NIF-size boule can be grown in 1 to 2 months from a small ''point'' seed. However, growing boules of adequate size is not sufficient. Care must be taken to prevent inclusions of growth solution and incorporation of atomically substituted 2. Implosions for ICF work far better at shorter wavelengths due to less generation of hot electrons, which preheat the fuel and make it harder to compress. Compromising between optic lifetime and implosion efficiency, both Nova and the NIF operate at a tripled frequency of the 1053-nm fundamental frequency of a neodymium glass laser. This tripling is accomplished by two crystals, one made of KDP and one made of deuterated KDP (DKDP). The first one mixes two 1053-nm photons to make 526-nm light, and the second one combines a residual 1053-nm photon with a 526-nm photon to make 351-nm light.},
doi = {10.2172/14145},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1999},
month = {9}
}

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